Browsing by Author "Arantes-Rodrigues, R."
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- Mice: An Animal Model for Bladder CancerPublication . Vasconcelos-Nóbrega, C.; Arantes-Rodrigues, R.; Colaço, A.; Santos, L.; Vala, Helena; Palomino, L. F.; Lopes, C.; Oliveira, P. A.Background: Bladder cancer is a common malignancy and an important cause of morbidity and mortality in western world. Animal models are the centre of experimental researches aiming to elucidate our knowledge about carcinogenesis, its treatment and prevention. Mice have a lower urinary tract comparable to humans. Methods: 22 ICR male mice were randomized into two groups (I and II). Group I was the negative control drinking tap water, and group II received N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) in drinking water during twelve weeks. Euthanasia was executed one week after BBN exposition. Results: All animals from Group I exhibited normal urothelium. In Group II, 100% of animals exhibited histological changes. 62.79% were preneoplastic lesions (simple hyperplasia, nodular hyperplasia, dysplasia) and 37.21% were neoplastic lesions (carcinoma in situ, invasive carcinoma, epidermoid metaplasia). Conclusions: Experimental urinary bladder tumours are useful models for the study of urinary bladder carcinogenesis and for the evaluation of new therapeutic strategies. In mice, chemically induced bladder cancer is nearly always of the invasive type and the incidence of spontaneous tumours is very rare. The similarity between human’s and mice’s bladder cancer allows the investigation of several aspects that can’t be studied under clinical conditions, such as pharmacokinetics and toxicity.
- Sex differences in bladder cancer chemoprevention by green teaPublication . Videira-Henriques, A.; Ferreira, S.; Almeida, L.; Arantes-Rodrigues, R.; Vasconcelos-Nóbrega, C.; Vala, Helena; Colaço, A.; Oliveira, P. A.; Oliveira, P. A .Background: In bladder cancer prevention studies, is important to investigate how both sexes respond to different agents. The purpose of this experiment was to evaluate the protective effect of green tea consumption in bladder cancer induced by N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in Mus musculus of both sexes. Methods: 21 male and 20 female mice were randomly assigned into three groups (I-Green tea+BBN, II-BBN and III-Green tea), in both sexes. The green tea was prepared daily at a concentration of 0,5% during 20 weeks and BBN was administrated by gavage in mean doses of 7,25 mg/mouse for week, through 10 weeks. After 20 weeks, animals were sacrificed and all bladders were collected for histological study. Results: In males, the group that showed a higher incidence of lesions was BBN + Green tea group. In females, the BBN group was the one with more histological lesions. A higher incidence of inflammatory infiltrate was observed in group exposed to BBN, followed the BBN+Green tea group, and finally green tea group. These observations were consistent for both sexes. Conclusions: We can conclude that green tea has a potential prevention effect of bladder cancer in females. The histological alterations were probably due to the influence of green tea in the metabolism acceleration of females and the protective effect of estrogens.
- Urethral tumor in mice induced by N-butyl-N-(4-hydroxybutyl) nitrosamine.Publication . Vasconcelos-Nóbrega, C.; Arantes-Rodrigues, R.; Henriques, A.; Colaço, A. A.; Ginj, M. D.; Santos, L. L.; Vala, Helena; Palomino, L. F.; Lopes, C. S.; Oliveira, P. A,Os tumores uretrais são patologias extremamente raras, representando menos de 1% de todas as neoplasias e menos de 0,1% das neoplasias genitourinárias. Até à data, estão descritos em humanos apenas cerca de 600 casos, quer do sexo masculino como feminino. A uretra, o tracto geniturinário e também a bexiga derivam embriologicamente de uma mesma estrutura, no entanto, os tumores que surgem nestes diferentes locais são distintos. O tumor mais frequentemente observado a nível uretral é o carcinoma das células escamosas, seguido pelo carcinoma das células de transição. A infecção e a irritação crónica são apontadas como factores etiológicos na carcinogénese da neoplasia uretral. No presente estudo, administrámos na água de bebida, N-butil-N-(4-hidroxibutil) nitrosamina (BBN) a um grupo de murganhos ICR, durante 12 semanas. Um outro grupo foi utilizado como controlo negativo. Os animais foram eutanasiados em três períodos diferentes e a bexiga e a uretra foram colhidas para procedimento histopatológico. Com este estudo, pretendemos mostrar as alterações pré-neoplásicas e neoplásicas induzidas pela BBN na uretra destes animais. De acordo com a bibliografia consultada, este é, até à data, o primeiro relato do efeito directo da BBN no epitélio uretral.