Navegando por Palavras-chave "retinoblastoma"
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- ItemSomente MetadadadosThe addition of ifosfamide/etoposide to cisplatin/teniposide improves the survival of children with retinoblastoma and orbital involvement(Lippincott Williams & Wilkins, 2007-10-01) Antoneli, Celia Beatriz Gianotti; Ribeiro, Karina Braga; Rodriguez-Galindo, Carlos; Soares, Fernando Augusto; Arias, Victor Eduardo Arrúa; Novaes, Paulo Eduardo Ribeiro dos Santos; Chojniak, Martha Maria Motono [UNIFESP]; Malogolowkin, Márcio; Universidade Federal de São Paulo (UNIFESP); Hosp Canc AC Camargo; St Jude Childrens Hosp; Childrens Hosp Los AngelesThis study aimed to determine the impact of the addition of ifosfamide/etoposide to a regimen containing cisplatin/temposide on the survival of patients with retinoblastoma with orbital involvement. Thirty patients were treated at the A. C. Camargo Hospital, Brazil, from 1986 to 2002. From 1986 to April 1992 (period 1, n = 12), treatment consisted of 3 cycles of induction chemotherapy with cisplatin and teniposide, followed by maintenance with same drugs alternating with cyclophosphamide. vincristine, and doxorubicin every 21 days for 60 weeks. Since April 1992 (period 11, n = 18), the treatment consisted of 3 cycles of ifamide and etoposide followed by maintenance with same drugs, alternating with cisplatin and teniposide every 21 days for 36 weeks. In both periods, children were submitted to exenteration with eyelid preservation and orbital radiation therapy with 45cGy, and also received intrathecal therapy with methotrexate plus dexamethasone and cytarabine. Kaplan-Meier method was used for survival analysis. The median age was 31 months. Most patients (86.7%) presented unilateral tumors. The 3-year overall survival was 34.4% and 72.2%, respectively, for patients treated during periods I and 11 (P = 0.061). The addition of ifosfamide/etoposide to chemotherapy with cisplatin/teniposide improves survival in these patients, but further studies are still necessary.
- ItemSomente MetadadadosThe effect of a selective cyclooxygenase-2 (COX-2) inhibitor on the proliferation rate of retinoblastoma cell lines(Nature Publishing Group, 2006-05-01) Souza, J. P. de; Corrêa, Zélia Maria da Silva [UNIFESP]; Marshall, J. C.; Anteka, E.; Coutinho, A. B.; Martins, M. C.; Burnier, M. N.; McGill Univ; Universidade Federal de São Paulo (UNIFESP); Retina & Oncol ServPurpose To examine the effect of nepafenac, a selective cyclooxygenase-2 (COX-2) inhibitor, on the proliferation rate of two human retinoblastoma (Rb) cell lines.Methods Two human Rb cell lines (WERI-RB and Y79) were cultured. COX-2 expression in these cell lines was verified by imunocytochemical analysis of cytospin sections and Western blotting. An MTT-based proliferation assay was used to compare Rb cell growth with and without amfenac, the active metabolite of nepafenac. the averaged results per condition were recorded. the Student's t-test was used to compare results from the cells cultured with and without amfenac.Result the Y79 cell line showed a higher proliferative rate than the WERI-RB cell line. Both cell lines were negative for COX-2 expression by immunocytochemical analysis; however, both cell lines were positive for COX-2 expression by Western blot. When amfenac was added to both of the cell lines, a statistically significant reduction in proliferation was observed in both cell lines. the two Rb cell lines were positive for COX-2 only in the Western blot, indicating that they probably express low levels of COX-2, which was undetectable by immucytochemical analysis.Conclusion the selective, anti-COX-2 molecule amfenac inhibited proliferation of both tested Rb cell lines. Further trials should be undertaken to study the effect of selective COX-2 inhibitors on Rb.
- ItemSomente MetadadadosThe effect of imatinib mesylate on the proliferation, invasive ability, and radiosensitivity of retinoblastoma cell lines(Nature Publishing Group, 2013-01-01) Moura, L. R. de; Marshall, J-C; Di Cesare, S.; Fernandes, B. F.; Antecka, E.; Burnier, M. N.; McGill Univ; Henry C Witelson Ocular Pathol Lab; Inst Brasileiro Oftalmol; Universidade Federal de São Paulo (UNIFESP)Purpose Our aim was to evaluate the potential effect of imatinib mesylate (IM), a small molecule that specifically inhibits the tyrosine quinase receptors, on the proliferation and invasive abilities of two human retinoblastoma (Rb) cell lines. Furthermore, the ability of IM to radiosensitize Rb cells was evaluated. the potential targets of IM (C-kit, PDGRF-alpha and -beta, and c-Abl) were also investigated in these cell lines.Methods Two human Rb cell lines (WERI-RB-1 and Y79) were cultured under normal growth conditions. An MTT-based proliferation assay and a Matrigel invasion assay were performed with and without exposure to 10 mu M of IM. the cells were also irradiated with graded dosages of 0, 2, 4, 6, 8, and 10 Gy with and without IM and their proliferations rates were analyzed. Western blot and immunocytochemical analysis of cytospins were performed to evaluate the expression of C-kit, PDGRF-alpha and -beta, and c-Abl.Results When IM was added to both cell lines a statistically significant (P<0.05) reduction in proliferation and invasive ability were observed. Exposure to IM also significantly increased the radiosensitivity of both Rb cell lines. the c-Abl expression was strongly positive, PDGRF-alpha and -beta expression were also positive but the C-kit expression was negative in both cell lines.Conclusions These results indicate that Gleevec may be useful as an adjuvant treatment in Rb patients, specially those considered for radiation therapy. Eye (2013) 27, 92-99; doi:10.1038/eye.2012.231; published online 16 November 2012
- ItemSomente MetadadadosLeydig cell tumor and mature teratoma: Unusual non-ocular tumors associated with sexual pseudo-precocity six years after unilateral retinoblastoma(Wiley-Blackwell, 2002-04-01) Seber, A.; Antoneli, CBG; Spinola-Castro, A. M.; Oyafuso, M. S.; Universidade Federal de São Paulo (UNIFESP); AC Camargo Hosp
- ItemSomente MetadadadosRelationship between histopathological features of chemotherapy treated retinoblastorna and P-glycoprotein expression(Blackwell Publishing, 2005-06-01) Souza, J. P.; Martins, M. C.; Caissie, A. L.; Torres, VLL; Fernandes, LHCF; Erwenne, C. M.; Burnier, M. N.; Universidade Federal de São Paulo (UNIFESP); McGill UnivBackground: P-glycoprotein (P-gp) has been identified as a possible mediator of chemoresistance in retinoblastoma. the aim of this study was to determine the expression of P-gp in retinoblastoma treated with chemotherapy prior to enucleation.Methods: Seventeen enucleated specimens of retinoblastoma from 16 patients were studied. Nine had been treated with chemotherapy alone, and eight had been treated with chemotherapy and other forms of local treatment. Tumour differentiation as well as choroidal and optic nerve invasion were assessed. P-gp immunohistochemical staining was performed and evaluated as negative, low or high.Results: Histopathological assessment of the cases showed that 14 of 17 eyes (82.3%) had viable retinoblastoma cells. Nine retinoblastomas were considered regressed with a well-differentiated component, five regressed retinoblastomas had viable cells with poor differentiation and three retinoblastomas had regressed leaving no viable cells. Sixteen of 17 retinoblastomas were P-gp positive. in the one case with optic nerve invasion and the three cases with massive choroidal invasion, P-gp expression was found in invading retinoblastoma cells.Conclusion: Almost all retinoblastomas expressed P-gp. High levels of P-gp expression might play a role in chemotherapy resistance of retinoblastoma or, conversely, chemotherapy might induce P-gp expression. These results might have an impact on management of bilateral retinoblastoma.
- ItemSomente MetadadadosRetinoblastoma in an adult: case report and literature review(Canadian Ophthal Soc, 2005-04-01) Odashiro, Alexandre Nakao [UNIFESP]; Pereira, P. R.; Souza Filho, João Pessoa de [UNIFESP]; Cruess, SR; Burnier Júnior, Miguel Noel Nascente [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); McGill UnivRetinoblastoma (RB) is a malignant neoplasm derived from photoreceptor precursor cells.' In more than 90% of cases, the diagnosis is established before the patient reaches 5 years of age.(2) RB is the most common intraocular malignant disease of childhood.(3) It is rare in adults and for this reason is not usually considered in the differential diagnosis of a retinal or intraocular mass in an adult.(4) We report a unilateral RB, with histopathological and immunohistochemical confirmation, in a 21-year-old woman. The base of the tumour had an area of well-differentiated cells resembling retinocytoma (RC), and in our view the RB came from this benign neoplasm.
- ItemSomente MetadadadosRetinoblastoma in children older than 5 years of age(Wiley-Blackwell, 2007-03-01) Aguirre Neto, Joaquim Caetano de; Gianotti Antoneli, Celia Beatriz; Ribeiro, Karina Braga; Simoes, Marcus; Novaes, Paulo Eduardo R. S.; Chojniak, Martha M. M.; Arias, Victor; Hosp Canc AC Camargo; Universidade Federal de São Paulo (UNIFESP)Background Retinoblastoma is a malignant tumor of the embryonic neural retina. About 80% of cases are diagnosed before age 4, with a median age at diagnosis of 2 years. Objective. To determine characteristics and prognosis of retinoblastoma in children older than 5 years. Procedures. From 1986 to 2002, medical records of 16 patients out of 453 cases referred to Hospital do Uncer AC Camargo, São Paulo, Brazil. Results. Median age at diagnosis was 73.7 months (range 65-144) and there was an equal gender distribution. Fifteen patients presented with unilateral disease. the mean time between first symptoms and diagnosis was 9.6 months (range 0-48). Most cases were diagnosed in advanced stages and 15 eyes were enucleated. Eleven patients presented with intraocular tumor (1 Reese II and 10 Reese V) and five presented with extraocular disease (one CCG II and four CCG III). Twelve patients are still alive with a median follow-up of 92 months (range 65-199). Conclusions. Because of its low incidence at this age, diagnosis of retinoblastoma is usually delayed due to low level of suspicion. Therefore, it is important that physicians are aware of this disease in orderto perform an earlier diagnosis, and decrease treatment-related morbidity.