Browsing by Author "Peixoto, Armando"
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- Association between Polymorphisms in Antioxidant Genes and Inflammatory Bowel DiseasePublication . Costa Pereira, Cristiana; Durães, Cecília; Coelho, Rosa; Grácio, Daniela; Silva, Marco; Peixoto, Armando; Lago, Paula; Pereira, Márcia; Catarino, Telmo; Pinho, Salomé; Teixeira, João Paulo; Macedo, Guilherme; Annese, Vito; Magro, FernandoInflammation is the driving force in inflammatory bowel disease (IBD) and its link to oxidative stress and carcinogenesis has long been accepted. The antioxidant system of the intestinal mucosa in IBD is compromised resulting in increased oxidative injury. This defective antioxidant system may be the result of genetic variants in antioxidant genes, which can represent susceptibility factors for IBD, namely Crohn's disease (CD) and ulcerative colitis (UC). Single nucleotide polymorphisms (SNPs) in the antioxidant genes SOD2 (rs4880) and GPX1 (rs1050450) were genotyped in a Portuguese population comprising 436 Crohn's disease and 367 ulcerative colitis patients, and 434 healthy controls. We found that the AA genotype in GPX1 is associated with ulcerative colitis (OR = 1.93, adjusted P-value = 0.037). Moreover, we found nominal significant associations between SOD2 and Crohn's disease susceptibility and disease subphenotypes but these did not withstand the correction for multiple testing. These findings indicate a possible link between disease phenotypes and antioxidant genes. These results suggest a potential role for antioxidant genes in IBD pathogenesis and should be considered in future association studies.
- Cancer Survivor Study (CASUS) on colorectal patients: longitudinal study on physical activity, fitness, nutrition, and its influences on quality of life, disease recurrence, and survivalPublication . Soares-Miranda, Luísa; Abreu, Sandra; Silva, Marco; Peixoto, Armando; Ramalho, Rosa; Correia da Silva, Pedro; Costa, Carla; Teixeira, João Paulo; Gonçalves, Carla; Moreira, Pedro; Mota, Jorge; Macedo, GuilhermePurpose: Evidence suggests that being physically active in combination with a healthy diet contributes to diminish colorectalcancerrisk.However,ifthisistruefor colorectalcancer primary prevention, the same is not clear for its recurrence after colorectal cancer treatments. Data on cancer survival are scarce, and there is a need for greater attention on these survivors’ lifestyle behavior. This manuscript describes rationale and design of the Cancer Survival Study (CASUS) on colorectalpatients,alongitudinalobservationalstudywiththe aim of investigating how physical activity, physical fitness, and dietary intakeare related with their quality of life, disease recurrence, and survival. Methods: The CASUS on colorectal patients is a longitudinal cohort study on colorectal survivors, aged 18 years or older, recruited 6,12,and 24 months after surgery.Upon recruitment, patients fill in a battery of questionnaires about physical activity, dietary intake, and quality of life, donate blood samples,do physical fitness tests, and use an accelerometer during 7 days. Repeated analyses will be performed to assess changes over time in physical activity, physical fitness, dietary intake, and other factors in relation t recurrence and survival. Conclusions: Results will contribute to highlight the role of physical activity, physical fitness, and nutrition in the quality of life of colorectal cancer survivors, recurrence, and survival. This study will provide important information for policy makers on the potential benefits of future physical activity and nutritional interventions, which are inexpensive, as a way to improve general health of colorectal cancer survivors.
- DNA Damage and Oxidative DNA Damage in Inflammatory Bowel DiseasePublication . Pereira, Cristiana; Coelho, Rosa; Grácio, Daniela; Dias, Cláudia; Silva, Marco; Peixoto, Armando; Lopes, Pedro; Costa, Carla; Teixeira, João Paulo; Macedo, Guilherme; Magro, FernandoBackground and aims: Inflammation has long been regarded as a major contributor to cellular oxidative damage and to be involved in the promotion of carcinogenesis. Methods: We aimed to investigate the oxidative damage in inflammatory bowel disease [IBD] patients through a case–control and prospective study involving 344 IBD patients and 294 healthy controls. DNA damage and oxidative DNA damage were measured by comet assay techniques, and oxidative stress by plasmatic lipid peroxidation, protein carbonyls, and total antioxidant capacity. Results: Higher DNA damage [p < 0.001] was found both in Crohn’s disease [CD] (9.7 arbitrary units [AU]; interquartile range [IQR]: 6.2–14.0) and ulcerative colitis [UC] [7.1 AU; IQR: 4.4–11.7], when compared with controls [5.4 AU; IQR: 3.8–6.8], and this was also the case with oxidative DNA damage [p < 0.001] [CD: 3.6 AU; IQR: 1.8–6.8; UC: 4.6 AU; IQR: 2.4–8.1], when compared with controls: 2.3 AU; IQR: 1.2–4.2]. Stratifying patients into groups according to therapy (5-aminosalicylic acid [5-ASA], azathioprine, anti-TNF, and combined therapy [azathioprine and anti-TNF]) revealed significant between-group differences in the level of DNA damage, both in CD and UC, with the combined therapy exhibiting the highest DNA damage levels [11.6 AU; IQR: 9.5–14.3, and 12.4 AU; IQR: 10.6–15.0, respectively]. Among CD patients, disease behaviour [B1 and B2], and age at diagnosis over 40 years [A3] stand as risk factors for DNA damage. For UC patients, the risk factors found for DNA damage were disease activity, treatment, age at diagnosis under 40 years [A1 + A2] and disease locations [E2 and E3]. Conclusions: In IBD there is an increase in DNA damage, and treatment, age at diagnosis and inflammatory burden seem to be risk factors.