9,331 research outputs found

    Adamantinomatous craniopharyngioma as a model to understand paracrine and senescence-induced tumourigenesis

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    Cellular senescence is a process that can prevent tumour development in a cell autonomous manner by imposing a stable cell cycle arrest after oncogene activation. Paradoxically, senescence can also promote tumour growth cell non-autonomously by creating a permissive tumour microenvironment that fuels tumour initiation, progression to malignancy and metastasis. In a pituitary tumour known as adamantinomatous craniopharyngioma (ACP), cells that carry oncogenic β-catenin mutations and overactivate the WNT signalling pathway form cell clusters that become senescent and activate a senescence-associated secretory phenotype (SASP). Research in mouse models of ACP has provided insights into the function of the senescent cell clusters and revealed a critical role for SASP-mediated activities in paracrine tumour initiation. In this review, we first discuss this research on ACP and subsequently explore the theme of paracrine tumourigenesis in other tumour models available in the literature. Evidence is accumulating supporting the notion that paracrine signalling brought about by senescent cells may underlie tumourigenesis across different tumours and cancer models

    The Influence of Adiposity Levels on the Relation between Perfluoroalkyl Substances and High Depressive Symptom Scores in Czech Adults

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    The extensive use and bioaccumulation of Perfluoroalkyl Substances (PFAS) over time raise concerns about their impact on health, including mental issues such as depression. This study aims to evaluate the association between PFAS and depression. In addition, considering the importance of PFAS as an endocrine disruptor and in adipogenesis, the analyses will also be stratified by body fat status. A cross-sectional study with 479 subjects (56.4% women, 25–89 years) was conducted. Four PFAS were measured: perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluorooctane sulfonate (PFOS). The Poisson regression model was applied using robust error variances. The fully adjusted model included age, sex, educational level, income, smoking, physical activity, body fat percentage, and the questionnaire to assess depression. The prevalence of depression and high body fat was 7.9% and 41.1%, respectively. Only PFOA was significantly associated with depression in the entire sample (prevalence rate (PR): 1.91; confidence interval (CI95%): 1.01–3.65). However, in the group with normal adiposity, PFOA (3.20, CI95%: 1.46–7.01), PFNA (2.54, CI95%: 1.29–5.00), and PFDA (2.09, CI95%: 1.09–4.00) were also significant. Future research should investigate the role of obesity as well as the biological plausibility and possible mechanisms increasing the limited number of evidences between PFAS and depression

    The Economics of the Public Option: Evidence from Local Pharmaceutical Markets

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    We study the effects of competition by state-owned firms, leveraging the decentralized entry of public pharmacies to local markets in Chile. Public pharmacies sell the same drugs at a third of private pharmacy prices, because of stronger upstream bargaining and market power in the private sector, but are of lower quality. Public pharmacies induced market segmentation and price increases in the private sector, which benefited the switchers to the public option but harmed the stayers. The countrywide entry of public pharmacies would reduce yearly consumer drug expenditure by 1.6 percent

    Stem cells and their role in pituitary tumorigenesis

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    The presence of adult pituitary stem cells (PSCs) has been described in murine systems by comprehensive cellular profiling and genetic lineage tracing experiments. PSCs are thought to maintain multipotent capacity throughout life and give rise to all hormone-producing cell lineages, playing a role in pituitary gland homeostasis. Additionally, PSCs have been proposed to play a role in pituitary tumorigenesis, in both adenomas and adamantinomatous craniopharyngiomas. In this manuscript, we discuss the different approaches used to demonstrate the presence of PSCs in the murine adult pituitary, from marker analyses to genetic tracing. In addition, we review the published literature suggesting the existence of tumor stem cells in mouse and human pituitary tumors. Finally, we discuss the potential role of PSCs in pituitary tumorigenesis in the context of current models of carcinogenesis and present evidence showing that in contrast to pituitary adenoma, which follows a classical cancer stem cell paradigm, a novel mechanism has been revealed for paracrine, non-cell autonomous tumor initiation in adamantinomatous craniopharyngioma, a benign but clinically aggressive pediatric tumor

    The response of a neutral atom to a strong laser field probed by transient absorption near the ionisation threshold

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    We present transient absorption spectra of an extreme ultraviolet attosecond pulse train in helium dressed by an 800 nm laser field with intensity ranging from 2times10122times10^{12} W/cm2^2 to 2times10142times10^{14} W/cm2^2. The energy range probed spans 16-42 eV, straddling the first ionisation energy of helium (24.59 eV). By changing the relative polarisation of the dressing field with respect to the attosecond pulse train polarisation we observe a large change in the modulation of the absorption reflecting the vectorial response to the dressing field. With parallel polarized dressing and probing fields, we observe significant modulations with periods of one half and one quarter of the dressing field period. With perpendicularly polarized dressing and probing fields, the modulations of the harmonics above the ionisation threshold are significantly suppressed. A full-dimensionality solution of the single-atom time-dependent Schr odinger equation obtained using the recently developed ab-initio time-dependent B-spline ADC method reproduce some of our observations

    Dysglycemia-Based Chronic Disease and Lifestyle Medicine: Mechanistic Interpretation Using the Allostatic Load Model

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    Dysglycemia-based chronic disease (DBCD) comprises insulin resistance, prediabetes, and type 2 diabetes, and their staged progression, complications, and impact contribute to one of the largest public health burdens worldwide. The clinical and economic effects of DBCD are fueled by external stressors related to modern society and lifestyles, especially in low socioeconomic strata. Chronic stressor exposure leads to chronic stress, characterized by immune-neuroendocrine activation and mobilization/depletion of metabolic resources. This complex adaptive response engaging many different signaling pathways is termed allostasis and principally regulates homeostatic mechanisms. Allostatic load is the metabolic cost of adaptation to environmental factors and can lead to numerous adverse health outcomes and behaviors. In this narrative review, the bidirectional relationship between allostatic load and unhealthy behaviors is analyzed in the context of DBCD development and progression, with a focus to reduce individual vulnerabilities

    Intracellular trafficking and cellular uptake mechanism of PHBV nanoparticles for targeted delivery in epithelial cell lines

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    Indexación: Web of Science; Scopus; Scielo.Background: Nanotechnology is a science that involves imaging, measurement, modeling and a manipulation of matter at the nanometric scale. One application of this technology is drug delivery systems based on nanoparticles obtained from natural or synthetic sources. An example of these systems is synthetized from poly(3-hydroxybutyrate-co-3-hydroxyvalerate), which is a biodegradable, biocompatible and a low production cost polymer. The aim of this work was to investigate the uptake mechanism of PHBV nanoparticles in two different epithelial cell lines (HeLa and SKOV-3). Results: As a first step, we characterized size, shape and surface charge of nanoparticles using dynamic light scattering and transmission electron microscopy. Intracellular incorporation was evaluated through flow cytometry and fluorescence microscopy using intracellular markers. We concluded that cellular uptake mechanism is carried out in a time, concentration and energy dependent way. Our results showed that nanoparticle uptake displays a cell-specific pattern, since we have observed different colocalization in two different cell lines. In HeLa (Cervical cancer cells) this process may occur via classical endocytosis pathway and some internalization via caveolin-dependent was also observed, whereas in SKOV-3 (Ovarian cancer cells) these patterns were not observed. Rearrangement of actin filaments showed differential nanoparticle internalization patterns for HeLa and SKOV-3. Additionally, final fate of nanoparticles was also determined, showing that in both cell lines, nanoparticles ended up in lysosomes but at different times, where they are finally degraded, thereby releasing their contents. Conclusions: Our results, provide novel insight about PHBV nanoparticles internalization suggesting that for develop a proper drug delivery system is critical understand the uptake mechanism.https://jnanobiotechnology.biomedcentral.com/articles/10.1186/s12951-016-0241-

    Patterns of Individual Shopping Behavior

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    Much of economic theory is built on observations of aggregate, rather than individual, behavior. Here, we present novel findings on human shopping patterns at the resolution of a single purchase. Our results suggest that much of our seemingly elective activity is actually driven by simple routines. While the interleaving of shopping events creates randomness at the small scale, on the whole consumer behavior is largely predictable. We also examine income-dependent differences in how people shop, and find that wealthy individuals are more likely to bundle shopping trips. These results validate previous work on mobility from cell phone data, while describing the unpredictability of behavior at higher resolution.Comment: 4 pages, 5 figure

    Senescence drives non-cell autonomous tumorigenesis in the pituitary gland

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    Novel detrimental functions of senescent cells have been recently uncovered in the context of cancer development and progression, which they mainly exert through the secretion of several pro-tumorigenic factors. Here we discuss how cellular senescence and its secretory phenotype can be involved in the widely unexplored phenomenon of paracrine tumorigenesis
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