Browsing by Author "Teixeira-Lemos, Edite"
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- Anti-inflammatory, anti-proliferative and antioxidant profiles of selective cyclooxygenase-2 inhibition as chemoprevention for rat bladder carcinogenesisPublication . Parada, Belmiro; Sereno, Jose; Reis, Flavio; Teixeira-Lemos, Edite; Garrido, Patricia; Pinto, Angela Filipa; Cunha, Maria Fernanda; Pinto, Rui; Mota, Alfredo; Figueiredo, Arnaldo; Teixeira, FredericoPurpose: To evaluate the efficacy of a selective cyclooxygenase-2 (COX-2) inhibitor in rat bladder cancer chemoprevention, as well as to assess the relevance of inflammation, proliferation and oxidative stress in tumor growth and in its prevention. Results: The main findings were: (I) the incidence of carcinoma was: control: 0% (0/8); BBN: 65% (13/20); CEL: 0% (0/8) and BBN + CEL: 12.5% (1/8); (II) the mean tumor volume per rat with tumor and per tumor were significantly lower in the BBN + CEL group (21.2 and 5.3 +/- 0.4 mm(3)) vs. BBN (138.5 +/- 7.5 and 112.5 +/- 6.4 mm(3)); (III) the incidence of pre-neoplasic (hyperplasia and dysplasia) and neoplasic (papillary tumors and carcinoma in situ-CIS) lesions were notoriously reduced in the CEL + BBN treatment; (IV) CEL significantly reduced serum TGF beta 1 and CRP and increase TNF alpha and IL-1 beta (p 0.001); (V) CEL reduced MDA formation in serum (p 0.001) and liver (p 0.05) and also showed a trend to reduction in kidney. Methods: Drug treatments were performed during the first 8 w, followed by 12 w for tumor expression/prevention, in the following groups: control-vehicle; carcinogen-0.05% of N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN); celecoxib (CEL)-10 mg/kg/day and preventive CEL + BBN. The bladders were analyzed for number and volume of tumor and nature of urothelium lesions. Serum was assessed for markers of inflammation, proliferation and redox status. Conclusions: Celecoxib has demonstrated an outstanding inhibitory effect on bladder cancer chemoprevention, which might be due to its expected anti-inflammatory actions, as well as by anti-proliferatory and antioxidant actions. This data supports a pivotal role of cancer chemoprevention strategies based on COX-2 inhibition.
- Erythropoietin Promotes Deleterious Cardiovascular Effects and Mortality Risk in a Rat Model of Chronic Sports DopingPublication . Piloto, Nuno; Teixeira, Helena M.; Teixeira-Lemos, Edite; Parada, Belmiro; Garrido, Patricia; Sereno, Jose; Pinto, Rui; Carvalho, Lina; Costa, Elisio; Belo, Luis; Santos-Silva, Alice; Teixeira, Frederico; Reis, FlavioAthletes who abuse recombinant human erythropoietin (rhEPO) consider only the benefit to performance and usually ignore the potential short and long-term liabilities. Elevated haematocrit and dehydratation associated with intense exercise may reveal undetected cardiovascular risk, but the mechanisms underlying it remain to be fully explained. This study aimed to evaluate the cardiovascular effects of rhEPO in rats under chronic aerobic exercise. A ten week protocol was performed in four male Wistar rat groups: control-sedentary; rhEPO-50 IU kg(-1), 3 times/wk; exercised (EX)-swimming for 1 h, 3 times/wk; EX + rhEPO. One rat of the EX + rhEPO group suffered a sudden death episode during the week 8. rhEPO in trained rats promoted erythrocyte count increase, hypertension, heart hypertrophy, sympathetic and serotonergic overactivation. The suddenly died rat's tissues presented brain with vascular congestion; left ventricular hypertrophy, together with a "cardiac-liver", suggesting the hypothesis of heart failure as cause of sudden death. In conclusion, rhEPO doping in rats under chronic exercise promotes not only the expected RBC count increment, suggesting hyperviscosity, but also other serious deleterious cardiovascular and thromboembolic modifications, including mortality risk, which might be known and assumed by all sports authorities, including athletes and their physicians.