RESUMEN
In this work, a quantitative spectroscopic study of the bleaching phenomena occurring in plasticized formulations containing poly(vinyl chloride) was performed, proposing a general methodology to comparatively analyze the effect of degrading conditions on the polyene accumulation behaviors (PABs) exhibited by a set of tested formulations. In the study, a set of environmental indexes (temperature (T*), UV energy (UV*), and days with rain) were proposed, which allowed for the suitable globalization of the changing environmental conditions occurring throughout the different degrading periods. A procedure to numerically describe the PAB, followed by each formulation undergoing each degrading condition was also proposed, which required only two primary fitting parameters and four secondary fitting parameters. Then, the combined effects of certain environmental conditions on the PABs were studied, quantifying the stabilizing effects of the rain and the combined decrement on the T* and UV* indexes. Finally, on the basis of the proposed fitting equation and the values of its fitting parameters, the relative importance of the dehydrochlorination reactions as compared with the photo-oxidative reactions simultaneously occurring in the studied systems was estimated.
RESUMEN
Acute coronary syndrome (ACS) is the leading cause of death in elderly patients worldwide. Due its participation in apoptosis, fibrosis, and angiogenesis, transforming growth factor-ß (TGF-ß) isoforms had been categorized as risk factors for cardiovascular diseases. However, due their contradictory activities, a cardioprotective role has been suggested. The aim was to measure the plasma levels of TGF-ß1, 2, and 3 proteins in patients with ACS. This was a case-control study including 225 subjects. The three activated isoforms were measured in serum using the Bio-Plex Pro TGF-ß assay by means of magnetic beads; the fluorescence intensity of reporter signal was read in a Bio-Plex Magpix instrument. We observed a significant reduction of the three activated isoforms of TGF-ß in patients with ACS. The three TGF-ß isoforms were positively correlated with each other in moderate-to-strong manner. TGFß-2 was inversely correlated with glucose and low-density lipoprotein (LDL)-cholesterol, whereas TGF-ß3 was inversely correlated with the serum cholesterol concentration. The production of TGF-ß1, TGF-ß2, and TGF-ß3 are decreased in the serum of patients with ACS. Further follow-up controlled studies with a larger sample size are needed, in order to test whether TGF-ß isoforms could be useful as biomarkers that complement the diagnosis of ACS.