RESUMO
The ability of a human B-cell lymphoma cell line to grow subcutaneously as tumors in nude mice was investigated. The effect of pretreating mice with cyclophosphamide or whole-body irradiation (WBI) was compared with no pretreatment of the mice. Both methods of pretreatment resulted in a higher tumor implantation rate, compared with that for non-pretreated controls. In mice that underwent WBI-pretreatment, a tumor implantation rate of 100% was observed, whereas mice pretreated with cyclophosphamide had a tumor implantation rate of 80%. In non-pretreated control mice, an implantation rate of only 50% was observed. Three weeks after injection, tumor size was significantly larger in mice of the pretreated groups, compared with that in mice of the group that did not receive pretreatment. Furthermore, particularly in the group pretreated with WBI, the tumors grew more synchronously, compared with tumors in the control group. Results of this study indicate that pretreatment with cyclophosphamide or WBI improves the tumor implantation rate of Ramos cells in nude mice, providing a workable animal model for studying human B-cell lymphoma.
Assuntos
Linfoma de Células B/patologia , Animais , Transplante de Células , Modelos Animais de Doenças , Feminino , Linfoma de Células B/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Neoplasias/métodos , Células Tumorais Cultivadas , Irradiação Corporal TotalRESUMO
Euthyroid multinodular goitre is caused by excessive replication of thyroid epithelial cells, due to various stimuli. With time there is a gradual increase in size and in nodularity. The clinical manifestations arise solely from thyroid enlargement. Treatment of euthyroid multinodular goitre is indicated only when thyroid enlargement causes symptoms of obstruction, such as dysphagia and dyspnoea. Treatment options are radioiodine (iodine-131), surgery and TSH suppression therapy. In this review we compare these treatment modalities. In our opinion, radioiodine is the treatment of choice in elderly patients, in patients in whom surgery is contra-indicated and in patients who are unwilling to undergo surgery. The life-time risk of fatal and non-fatal cancer due to radioiodine is negligible in patients over 65 years of age, compared with the life-time risk of fatal cancer in the non-exposed population.