Publications by authors named "Miguel Vargas"

Introduction: Breast cancer (BC) is the leading cause of cancer-related deaths among women, with triple-negative breast cancer (TNBC) representing one of the most aggressive and treatment-resistant subtypes. In this study, we aimed to evaluate the antitumor potential of C14 and P8 molecules in both TNBC and radioresistant TNBC cells. These compounds were chosen for their ability to stabilize the complex formed by the overactivated form of K-Ras4B and its membrane transporter (PDE6δ).

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Among malignant neoplasms, pancreatic ductal adenocarcinoma (PDAC) has one of the highest fatality rates due to its late detection. Therefore, it is essential to discover a noninvasive, early, specific, and sensitive diagnostic method. MicroRNAs (miRNAs) are attractive biomarkers because they are accessible, highly specific, and sensitive.

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Pancreatic ductal adenocarcinoma (PDAC) has the worst prognosis among all human cancers as it is highly resistant to chemotherapy. K-Ras mutations usually trigger the development and progression of PDAC. We hypothesized that compounds stabilizing the KRas4B/PDE6δ complex could serve as PDAC treatments.

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In 40-50% of colorectal cancer (CRC) cases, K-Ras gene mutations occur, which induce the expression of the K-Ras4B oncogenic isoform. K-Ras4B is transported by phosphodiesterase-6δ (PDE6δ) to the plasma membrane, where the K-Ras4B-PDE6δ complex dissociates and K-Ras4B, coupled to the plasma membrane, activates signaling pathways that favor cancer aggressiveness. Thus, the inhibition of the K-Ras4B-PDE6δ dissociation using specific small molecules could be a new strategy for the treatment of patients with CRC.

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Student satisfaction is a crucial determinant of success in online education, but studies on satisfaction with virtual classes during the COVID-19 outbreak are still scarce. This research contributes empirical evidence regarding the determinants of overall satisfaction with online classes and academic performance through the domain satisfaction approach. Additionally, we introduce to the psychological literature the two-layer model, a well-known econometric methodology, to estimate the effect of domain satisfaction while controlling the impact of unobserved individual differences.

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Renal involvement in COVID-19 infection is varied and worsens its outcome and prognosis. However, the association of COVID-19 infection with glomerulonephritis is exceptional. We report a 46-year-old woman with COVID-19 who had an acute kidney injury and ANCA associated glomerulonephritis two weeks after the onset of the disease.

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The effect of weight loss on the periodontal condition remains unclear. The present prospective study thus aimed to evaluate the effect of weight loss on the periodontal status of 57 obese patients (BMI ≥30 kg/m) with ages ranging from 18 to 60 years, at 12 months following bariatric surgery. Demographic, biological and behavioral variables were analyzed.

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In the nematode Caenorhabditis elegans, signals derived from bacteria in the diet, the animal's major nutrient source, can modulate both behavior and healthspan. Here we describe a dual role for trimethylamine (TMA), a human gut flora metabolite, which acts as a nutrient signal and a neurotoxin. TMA and its associated metabolites are produced by the human gut microbiome and have been suggested to serve as risk biomarkers for diabetes and cardiovascular diseases.

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Pancreatic cancer is highly lethal and has a poor prognosis. The most common alteration during the formation of pancreatic tumors is the activation of KRAS (Kirsten rat sarcoma 2 viral oncogene homolog) oncogene. As a new therapeutic strategy, the C19 molecule ((2S)--(2,5-dichlorophenyl)-2-[(3,4-dimethoxyphenyl)-methylamine]propanamide) blocks the KRAS-membrane association in cancer cells.

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This paper investigates the structure and composition of the social network formed on the campus of the Faculty of Economics and Business of Diego Portales University, Chile, exposing a series of characteristics that are aligned with similar research in the field of networks. We use a model of social networks formation in order to understand socioeconomic and academic factors that predict the formation of friendship between two students. Specifically, we test empirically our model, using students' administrative information.

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Our aim is to cast light on socioeconomic residential segregation effects on life satisfaction (LS). In order to test our hypothesis, we use survey data from Chile (Casen) for the years 2011 and 2013. We use the Duncan Index to measure segregation based on income at the municipality level for 324 municipalities.

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Epigenetic mechanisms such as histone acetylation and deacetylation participate in regulation of the genes involved in encystation of Entamoeba invadens. However, the histones and target residues involved, and whether the acetylation and deacetylation of the histones leads to the regulation of gene expression associated with the encystation of this parasite, remain unknown. In this study, we found that E.

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Obesity and periodontitis are among the most common non-communicable diseases, and epidemiological studies report the influence of obesity in the onset and progression of periodontitis. Data indicate that increased body mass index, waist circumference, percentage of subcutaneous body fat, and serum lipid levels are associated with increased risk to develop periodontitis. The underlying biological mechanisms of this association involve adipose tissue-derived cytokines, such as tumour necrosis factor-α and interleukin-6, which affect whole-body metabolism and contribute to the development of a low-grade systemic inflammation.

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Post-translational modifications of histone H3 N-terminal tails are key epigenetic regulators of virulence gene expression and sexual commitment in the human malaria parasite Here, we identify proteolytic clipping of the N-terminal tail of nucleosome-associated histone H3 at amino acid position 21 as a new chromatin modification. A cathepsin C-like proteolytic clipping activity is observed in nuclear parasite extracts. Notably, an ectopically expressed version of clipped histone H3, PfH3p-HA, is targeted to the nucleus and integrates into mononucleosomes.

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Background: The GTPase KRas4B has been utilized as a principal target in the development of anticancer drugs. PDE6δ transports KRas4B to the plasma membrane, where it is released to activate various signaling pathways required for the initiation and maintenance of cancer. Therefore, identifying new small molecules that prevent activation of this GTPase by stabilizing the KRas4B-PDE6δ molecular complex is a practical strategy to fight against cancer.

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Actin is one of the most conserved, abundant, and ubiquitous proteins in all eukaryotes characterised to date. Posttranslation modifications of actin modify the organisation of the actin-rich cytoskeleton. In particular, chemical modifications of actin's amino-terminal region determine how filamentous actin is organised into scaffolds.

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Background: Colorectal cancer is the third most common cancer worldwide; and in 40% of all cases, KRAS4b-activating mutations occur. KRAS4b is transported by phosphodiesterase-6δ (PDEδ) to the plasma membrane, where it gets activated. PDEδ downregulation prevents redistribution and activation of KRAS4b.

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The telomeres of the malaria parasite Plasmodium falciparum are essential not only for chromosome end maintenance during blood stage development in humans but also to generate genetic diversity by facilitating homologous recombination of subtelomeric, multigene virulence families such as var and rifin. However, other than the telomerase PfTERT, proteins that act at P. falciparum telomeres are poorly characterised.

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RhoGDI proteins have been implicated in several human cancers; changes in their expression levels have shown pro- or anti-tumorigenic effects. Pancreatic Ductal Adenocarcinoma (PDAC) is a complex pathology, with poor prognosis, and most patients die shortly after diagnosis. Efforts have been focused on understanding the role of RhoGDI's in PDAC, specially, RhoGDI1 and RhoGDI2.

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Small GTPases are signalling molecules that regulate important cellular processes. GTPases are deactivated by GTPase-activating proteins (GAPs). While human GAPs have been intensively studied, no GAP has yet been characterized in Entamoeba histolytica.

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Background: The aim of this systematic review is to evaluate whether use of local or systemic antimicrobials would improve clinical results of non-surgical periodontal therapy for smokers with chronic periodontitis (CP).

Methods: Medical Literature Analysis and Retrieval System Online, Excerpta Medica Database, and The Cochrane Central Register of Controlled Trials were searched up to and including March 2016. Randomized clinical trials of duration of at least 6 months were included if they reported on treatment of smokers (≥10 cigarettes per day for minimum 12 months) with CP with non-surgical periodontal therapy either alone or associated with local or systemic antimicrobials.

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In this work, the authors present two eHealth platforms that are examples of how health systems are migrating from client-server architecture to the web-based and ubiquitous paradigm. These two platforms were modeled, designed, developed and implemented with positive results. First, using ambient-assisted living and ubiquitous computing, the authors enhance how palliative care is being provided to the elderly patients and patients with terminal illness, making the work of doctors, nurses and other health actors easier.

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Background: In human hosts, Entamoeba histolytica cysts can develop into trophozoites, suggesting that the life cycle of this parasite are regulated by changes in gene expression. To date, some evidence has suggested that epigenetic mechanisms such as DNA methylation and histone modification are involved in the regulation of gene expression in Entamoeba. Some post-translational modifications (PTMs) at the N-terminus of E.

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Thyrotropin-releasing hormone (TRH) synthesized in hypothalamic paraventricular nucleus directs hypothalamus-pituitary-thyroid (HPT) axis function, regulating thyrotropin release from adenohypophysis and thyroid hormones serum concentration. Pyroglutamyl aminopeptidase II (PPII), a Zn-dependent metallopeptidase located in adenohypophysis and medial-basal-hypothalamus degrades TRH released from the median eminence and participates in HPT axis function by regulating TRH-induced thyrotropin release from adenohypophysis. It is unknown whether dietary Zn deficiency down-regulates PPII.

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