RESUMO
Translation initiation of the human immunodeficiency virus-type 1 (HIV-1) genomic mRNA (vRNA) is cap-dependent or mediated by an internal ribosome entry site (IRES). The HIV-1 IRES requires IRES-transacting factors (ITAFs) for function. In this study, we evaluated the role of the heterogeneous nuclear ribonucleoprotein K (hnRNPK) as a potential ITAF for the HIV-1 IRES. In HIV-1-expressing cells, the depletion of hnRNPK reduced HIV-1 vRNA translation. Furthermore, both the depletion and overexpression of hnRNPK modulated HIV-1 IRES activity. Phosphorylations and protein arginine methyltransferase 1 (PRMT1)-induced asymmetrical dimethylation (aDMA) of hnRNPK strongly impacted the protein's ability to promote the activity of the HIV-1 IRES. We also show that hnRNPK acts as an ITAF for the human T cell lymphotropic virus-type 1 (HTLV-1) IRES, present in the 5'UTR of the viral sense mRNA, but not for the IRES present in the antisense spliced transcript encoding the HTLV-1 basic leucine zipper protein (sHBZ). This study provides evidence for a novel role of the host hnRNPK as an ITAF that stimulates IRES-mediated translation initiation for the retroviruses HIV-1 and HTLV-1.
Assuntos
Ribonucleoproteínas Nucleares Heterogêneas Grupo K , Retroviridae , Humanos , Regiões 5' não Traduzidas , Ribonucleoproteínas Nucleares Heterogêneas Grupo K/genética , Ribonucleoproteínas Nucleares Heterogêneas Grupo K/metabolismo , Sítios Internos de Entrada Ribossomal/genética , Fosforilação , Biossíntese de Proteínas , Processamento de Proteína Pós-Traducional , Proteína-Arginina N-Metiltransferases/metabolismo , Proteínas Repressoras/metabolismo , Retroviridae/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
Luminescent solar concentrators (LSCs) have become an attractive way to produce green energy via their integration into buildings as photovoltaic windows. Recently, carbon quantum dots (C-QDs) have become the most studied luminescent material for the manufacture of luminescent solar concentrators due to their advantages, such as low toxicity, sustainability, and low cost. Despite the advantages of carbon quantum dots, they remain a low-efficiency material, and it is difficult to fabricate LSCs with a good performance. To address this problem, some of the research has used SiO2 nanoparticles (Nps) to produce a light-scattering effect that helps to improve the system performance. However, these studies are limited and have not been discussed in detail. In this regard, this research work was designed to evaluate the contribution of the scattering effect in different systems of carbon quantum dots used in a possible luminescent solar concentrator. To carry out this study, C-QDs and SiO2 Nps were synthesized by hydrothermal methods and the Stober method, respectively. We used different concentrations of both materials to fabricate film LSCs (10 × 10 cm2). The results show that the light scattered by the SiO2 Nps has a double contribution, in terms of light redirected towards the edges of the window and as a secondary source of excitation for the C-QDs; thus, an improvement in the performance of the LSC is achieved. The best improvement in photoluminescence is achieved when the films are composed of 20% wt carbon quantum dots and 10% wt SiO2 Nps, reaching a gain of 16% of the intensity of the light incident on the edges of the window with respect to the LSCs where only C-QDs were used.
RESUMO
AIM: To assess the oncological outcomes of patients with early breast cancer treated with breast-conserving surgery and adjuvant hypofractionated radiation therapy. METHODS AND MATERIAL: This retrospective analysis included all patients ≥50 year of age with T1-2 N0 M0 breast cancer treated at our Radiation Oncology Unit between 2008 and 2011. Whole-breast radiation therapy was delivered to a dose of 42.5â¯Gy in 16 fractions, without boost. The primary outcome was local control. RESULTS: 212 patients were identified. With a median follow up of 60 months, we found 3% local recurrence and 5.3% regional and/or distant recurrences. At the moment of data analysis, 17 patients had died. Out of 5 local recurrences, 2 had previously had a distant recurrence, both of them died. The other three were still alive at the last follow up. These results are comparable to those observed in Phase III trials that use this fractionation scheme. CONCLUSIONS: The results obtained with this retrospective analysis are comparable to those obtained in large randomized trials. This data also supports the use of hypofractionated radiation therapy in Latin America. Hypofractionated radiation therapy for early breast cancer patients should be the standard adjuvant treatment.
RESUMO
The Systolic Blood Pressure Intervention Trial (SPRINT) tested whether a systolic blood pressure (SBP) value <120 mm Hg reduces adverse clinical outcomes compared with the goal of <140 mm Hg. Here the authors describe the baseline characteristics of Hispanic participants in SPRINT. Nondiabetic hypertensive patients 50 years and older with SBP 130-180 mm Hg taking zero to four blood pressure (BP) medications were enrolled from the mainland United States and Puerto Rico. Cross-sectional, bivariate analysis was employed comparing sociodemographic and clinical factors in Hispanics vs non-Hispanics. Multivariable logistic regression models restricted to Hispanics were used to identify factors associated with achieved BP control (SBP <140 mm Hg and diastolic BP <90 mm Hg) at baseline. Eleven percent (n=984) of SPRINT participants were Hispanic; 56% (n=549) of Hispanics were living in Puerto Rico and the remainder were living on the US mainland. Hispanics overall were younger, more often female, less likely to live alone, and more likely to have lower education and be uninsured, although just as likely to be employed compared with non-Hispanics. BP control was not different between Hispanics vs non-Hispanics at baseline. However, a significantly higher percentage of Hispanics on the US mainland (compared with Hispanics in Puerto Rico) had controlled BP. BP control was independently associated with cardiovascular disease history and functional status among Hispanics, specifically those living in Puerto Rico, whereas functional status was the only independent predictor of BP control identified among mainland Hispanics. These findings highlight the diversity of the SPRINT population. It remains to be seen whether factors identified among Hispanics impact intervention goals and subsequent clinical outcomes.