Obstructive Sleep Apnea: New insights into antioxidant activity and cellular response to stress

This work was approved by the Ethical Committee of INSA.I.P.-Lisboa, Centro Hospitalar Lisboa-Norte., Faculdade de Ciências Médicas da Universidade Nova de Lisboa and Comissão Nacional de Proteção de Dados, Portugal.DIGE images were obtained in ITQB.Obstructive sleep apnea (OSA) is a sleep¬related breathing disorder characterized by recurrent episodes of apnea/and hypopnea during sleep with resultant intermittent hypoxia and sleep fragmentation, leading to cardiometabolic diseases. OSA affects 3.7% to 26% of adult population, but frequently is underdiagnosed. By 2DIGE-proteomics approach, we have investigated red blood cells (RBC) in OSA to uncover new insights into putative chronic stress-induced RBC dysfunction that lead to inflammation and metabolic syndrome associated with OSA. A number of proteins as potential candidate biomarkers for OSA, such as the cytosolic antioxidant regulators, catalase (CAT) and peroxiredoxin2 (PRX2) was identified, needing additional biochemical research validation.Project - Obstructive sleep apnea and associated metabolic/cardiovascular disorders: understanding mechanisms towards early diagnosis and prognosis prediction. Work partially supported by Harvard Medical School-Portugal Program (HMSP-ICJ/0022/2011), FCT/Poly-Annual Funding Program and FEDER/Saúde XXI Program (Portugal)

Polyamide synthesis from 6-aminocapronitrile, Part 2: Heterogeneously catalyzed nitrile hydrolysis with consecutive amine amidation

To test the potential of heterogeneous catalysts for the nylon-6 synthesis from 6-aminocapronitrile, a number of zeolites, aluminum silicate, and metal oxides were tested as catalysts for the model reaction of pentanenitrile with water and hexylamine to N-hexylpentanamide. All zeolitic and aluminum silicate systems showed an insufficient performance, while the metal oxides (TiO2, ZrO2, Nb2O5) showed very promising results. The kinetic behavior of the metal oxides was further investigated. First the nitrile was catalytically hydrolyzed to the terminal amide and subsequently the amidation of the hexylamine occurred. To polymerize 6-aminocapronitrile into nylon-6, more than 99 % nitrile conversion was required to obtain a high-molecular-weight polymer. Pentanenitrile conversions larger than 99 % can be obtained within six hours, at 230 °C, by using ZrO2 as the catalyst. A kinetic study (by using IR spectroscopy) on the behavior of the metal oxides demonstrated that the adsorbed nitrile was catalytically hydrolyzed at the surface, but remained tightly bound to the surface. Zirconia-catalyzed polymerizations of 6-amino-capronitrile demonstrated that high-molecular-weight nylon-6 is feasible by using this route