Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Ann Oncol ; 24(8): 2043-7, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23609186

RESUMO

BACKGROUND: The aim of the present study was to demonstrate that radical hysterectomy (RH) leads to improved survival outcomes in FIGO stage IB2-IIB cervical cancer when compared with standard brachytherapy (BCT) after identical external beam chemoradiation (EBRT-CT). PATIENTS AND METHODS: EBRT-CT treatment consisted of six courses of cisplatin at 40 mg/m² and gemcitabine at 125 mg/m² per week concurrent with 50.4 Gy of radiation. In the BCT arm, EBRT-CT was followed by BCT to reach a point A dose of 85 Gy, whereas in the experimental arm, a type III RH with bilateral pelvic lymph node dissection and para-aortic lymph node sampling (RH) was carried out within 4-6 weeks after EBRT-CT. RESULTS: Between May 2004 and June 2009, 211 patients were enrolled (BCT, 100 and RH, 111). At a median follow-up time of 36 months (3-80), progression-free survival (PFS) and overall survival (OS) rates were similar in both the arms. PFS rates were 74.8% and 71.7% in the BCT and RH arms [HR 0.6516 (95% confidence interval (CI) 0.3504-1.2116)], P = 0.186. OS rates were 76.3% in the BCT versus 74.5% in the surgical arm [HR 0.6981 (95% CI 0.3106-1.3439)], P = 0.236. No differences were observed in the pattern of local and systemic failures. CONCLUSIONS: This study failed to demonstrate that RH after EBRT-CT is superior to standard BCT.


Assuntos
Braquiterapia , Cisplatino/uso terapêutico , Desoxicitidina/análogos & derivados , Histerectomia , Neoplasias do Colo do Útero , Adulto , Idoso , Quimiorradioterapia , Desoxicitidina/uso terapêutico , Intervalo Livre de Doença , Feminino , Humanos , Pessoa de Meia-Idade , Radiossensibilizantes/uso terapêutico , Sobrevida , Resultado do Tratamento , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/mortalidade , Neoplasias do Colo do Útero/radioterapia , Neoplasias do Colo do Útero/cirurgia , Adulto Jovem , Gencitabina
2.
Br J Cancer ; 97(3): 322-6, 2007 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-17609666

RESUMO

The blood-brain barrier (BBB) hampers delivery of several drugs including chemotherapeutics to the brain. The drug efflux pump P-glycoprotein (P-gp), expressed on brain capillary endothelial cells, is part of the BBB. P-gp expression on capillary endothelium decreases 5 days after brain irradiation, which may reduce P-gp function and increase brain levels of P-gp substrates. To elucidate whether radiation therapy reduces P-gp expression and function in the brain, right hemispheres of rats were irradiated with single doses of 2-25 Gy followed by 10 mg kg(-1) of the P-gp substrate cyclosporine A (CsA) intravenously (i.v.), with once 15 Gy followed by CsA (10, 15 or 20 mg kg(-1)), or with fractionated irradiation (4 x 5 Gy) followed by CsA (10 mg kg(-1)) 5 days later. Additionally, four groups of three rats received 25 Gy once and were killed 10, 15, 20 or 25 days later. The brains were removed and P-gp detected immunohistochemically. P-gp function was assessed by [(11)C]carvedilol uptake using quantitative autoradiography. Irradiation increased [(11)C]carvedilol uptake dose-dependently, to a maximum of 20% above non irradiated hemisphere. CsA increased [(11)C]carvedilol uptake dose-dependently in both hemispheres, but more (P<0.001) in the irradiated hemisphere. Fractionated irradiation resulted in a lost P-gp expression 10 days after start irradiation, which coincided with increased [(11)C]carvedilol uptake. P-gp expression decreased between day 15 and 20 after single dose irradiation, and increased again thereafter. Rat brain irradiation results in a temporary decreased P-gp function.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Encéfalo/efeitos da radiação , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/fisiologia , Animais , Autorradiografia , Encéfalo/metabolismo , Carbazóis/metabolismo , Carvedilol , Imuno-Histoquímica , Masculino , Propanolaminas/metabolismo , Ensaio Radioligante , Ratos , Ratos Wistar
3.
Eur J Cancer ; 40(14): 2064-70, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15341980

RESUMO

The drug-efflux pumps P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1) are present in the blood-testis barrier (BTB) and may hamper the delivery of cytotoxic drugs to the testis. The precise localisation of P-gp and MRP1 in testicular tissue and the presence of the efflux pumps MRP2 and breast cancer resistance protein (BCRP) in the BTB are unknown. We therefore studied the localisation of these pumps in the BTB in normal testis (n = 12), in non-seminoma (n = 10) seminoma (n = 10), and testicular lymphoma (n = 9). Slides were scored semi-quantitatively for P-gp, MRP1, MRP2 and BCRP and blood vessels with factor VIII antibody. In normal testis, P-gp and BCRP were strongly expressed by myoid cells and luminal capillary endothelial wall and P-gp also by Leydig cells. MRP1 was observed at the basal side of Sertoli cells and on Leydig cells. MRP2 was only weakly expressed by myoid cells. Seminomas and non-seminomas expressed P-gp and/or BCRP and/or MRP1, lymphomas strongly expressed P-gp, weakly expressed BCRP and did not or showed weak expression of MRP1. There was very little staining for MRP2 in the tumours. Newly formed vessels in all tumours only expressed P-gp and BCRP. P-gp, BCRP and MRP1 are present in different cell layers of the normal testis, suggesting the optimal protection of spermatogenesis. In germ cell tumours, this expression pattern may explain the chemoresistance observed to P-gp, BCRP and MRP1 substrates. In germ cell tumours and testicular lymphomas, P-gp and BCRP expression by tumour cells and by newly formed vessels may also contribute to chemoresistance. These findings underscore the importance of removing the affected testis in cases of primary germ cell tumours and testicular lymphomas, irrespective of whether the patient has already undergone chemotherapy.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/análise , Transportadores de Cassetes de Ligação de ATP/análise , Barreira Hematotesticular/química , Proteínas Associadas à Resistência a Múltiplos Medicamentos/análise , Seminoma/química , Neoplasias Testiculares/química , Humanos , Imuno-Histoquímica , Masculino
4.
Appl Radiat Isot ; 57(4): 505-7, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12361330

RESUMO

This paper describes an improved preparation of [11C]verapamil by reaction of [11C]methyl triflate with desmethylverapamil. The optimal reaction temperature, amount of precursor and reaction time were assessed. With this method [11C]verapamil can be prepared with a reproducible radiochemical yield of 66 +/- 4% (EOB, based on [11C]methyltriflate). Total synthesis time was 60 min. Radiochemical purity was >99% and specific activities varied between 5 and 30TBq/mmol.


Assuntos
Radioisótopos de Carbono , Verapamil/análogos & derivados , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Radioisótopos de Carbono/química , Resistencia a Medicamentos Antineoplásicos , Humanos , Mesilatos , Métodos , Radioquímica , Temperatura , Tomografia Computadorizada de Emissão , Verapamil/síntese química , Verapamil/isolamento & purificação
5.
Neurochem Int ; 40(2): 145-55, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11738481

RESUMO

Five potent, lipophilic beta-adrenoceptor antagonists (carvedilol, pindolol, toliprolol and fluorinated analogs of bupranolol and penbutolol) were labeled with either carbon-11 or fluorine-18 and evaluated for cerebral beta-adrenoceptor imaging in experimental animals. The standard radioligand for autoradiography of beta-adrenoceptors, [125I]-iodocyanopindolol, was also included in this survey. All compounds showed either very low uptake in rat brain or a regional distribution that was not related to beta-adrenoceptors, whereas some ligands did display specific binding in heart and lungs. Apparently, the criteria of a high affinity and a moderately high lipophilicity were insufficient to predict the suitability of beta-adrenergic antagonists for visualization of beta-adrenoceptors in the central nervous system.


Assuntos
Antagonistas Adrenérgicos beta/síntese química , Encéfalo/diagnóstico por imagem , Receptores Adrenérgicos beta/análise , Tomografia Computadorizada de Emissão/métodos , Antagonistas Adrenérgicos beta/farmacocinética , Animais , Encéfalo/metabolismo , Bupranolol/síntese química , Bupranolol/farmacocinética , Carbazóis/síntese química , Carbazóis/farmacocinética , Radioisótopos de Carbono , Carvedilol , Radioisótopos de Flúor , Masculino , Modelos Animais , Especificidade de Órgãos , Pindolol/síntese química , Pindolol/farmacocinética , Propanolaminas/síntese química , Propanolaminas/farmacocinética , Propranolol/síntese química , Propranolol/farmacocinética , Ensaio Radioligante , Ratos , Ratos Wistar , Distribuição Tecidual
6.
Synapse ; 35(1): 62-7, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10579809

RESUMO

The muscarinic antagonist N-[(11)C]methyl-piperidin-4-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate (VC-004) 1 was tested for visualization of muscarinic receptors in the brain. The active (R)-isomer (pKb = 10.92) was labeled by reacting [(11)C]-CH(3)I with the secondary amine precursor (40-60% decay-corrected radiochemical yield, specific activity 13.0-34.3 TBq/mmol, 45 min after end of bombardment). Biodistribution studies were performed in male Wistar rats. Brain uptake of (R)-[(11)C]-VC-004 was high, standard uptake values (SUVs) ranging from 1.6 in cerebellum to 3.3 in frontal cortex. In all brain regions, the nonsubtype selective muscarinic antagonist scopolamine (2.5 mg/kg) blocked (R)-[(11)C]-VC-004 binding to the same extent (84.6 +/- 3.3%) as nonlabeled (R)-VC-004 (2.0 mg/kg, 83.2 +/- 4.6%). In contrast, the fraction of [(11)C]VC-004 binding which was blocked by atropine (2.5 mg/kg) was significantly smaller (54 +/- 17%). The reduction of (R)-[(11)C]-VC-004 binding by low-dose atropine (0.5 mg/kg) was not significantly different from that caused by (R)-(-)-QNB (20 microg/kg). The decrease in specific binding of (R)-[(11)C]VC-004 after (R)-(-)-QNB block correlated well with literature values for the percentages of M(2) receptors in the brain regions studied. (R)-[(11)C]VC-004 was rapidly cleared from plasma (92% with a half-life of 0.27 min) and the fraction of total plasma radioactivity representing parent compound decreased from 99% to 42% at 10 min postinjection. Although (R)-[(11)C]VC-004 can visualize muscarinic receptors in the brain, it does not show selectivity for the M(2)-subtype. A low dose (0.5 mg/kg) of atropine seems to preferentially block M(2)-receptors in vivo, as has been reported for (R)-(-)-QNB.


Assuntos
Encéfalo/diagnóstico por imagem , Fenilacetatos/farmacocinética , Receptores Muscarínicos/metabolismo , Animais , Masculino , Antagonistas Muscarínicos/farmacologia , Quinuclidinil Benzilato/farmacologia , Ensaio Radioligante , Ratos , Ratos Wistar , Tomografia Computadorizada de Emissão
7.
Clin Pediatr (Phila) ; 33(12): 720-5, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7874824

RESUMO

Routine supplementation with multivitamins is recommended for all patients with cystic fibrosis (CF). The purpose of this study was to investigate how well patients at a large CF clinic follow recommendations for taking multivitamins and what factors affect use. A questionnaire was developed and sent to the 150 patients actively followed at our center. Of the 80 patients who returned the survey, only 47% followed clinic recommendations. Of those patients not taking extra supplements, serum vitamin A and E levels varied widely, although most were within the normal range (vitamin A 11-87 micrograms/dL, tocopherol 0.4-2.3 mg/dL, tocopherol/cholesterol 3.0-9.6 mg/g). Only 25% of respondents had known insurance coverage for vitamins. Gender or educational level did not affect adherence; however, those with minimal pulmonary disease (forced vital capacity [FVC] greater than 70% of predicted) were more likely to take vitamins than those with moderate or severe disease (P < .05). In addition to malabsorption, poor adherence should be considered by both CF specialists and primary-care providers as a cause of low serum vitamin A and E levels, especially in patients with moderate to severe lung disease.


Assuntos
Fibrose Cística/tratamento farmacológico , Cooperação do Paciente , Vitaminas/uso terapêutico , Criança , Pré-Escolar , Fibrose Cística/sangue , Humanos , Inquéritos e Questionários , Vitamina A/sangue , Vitamina E/sangue , Vitaminas/administração & dosagem
8.
Clin Exp Immunol ; 88(1): 10-6, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1563094

RESUMO

The European collaborative study of HIV-infected pregnant women in Europe now indicates a 13% risk of fetal HIV infection (originally thought to be about 30%, and possibly higher in some countries). Several reports suggest trans-placental passage. However, the detailed mechanisms associated with such vertical transmission have not yet been clarified. We have examined the possibility that HIV enters placental tissue from maternal blood via binding to CD4 and Fc receptors (FcR) at the trophoblast level, allowing intraplacental infection. Here we report the detection of several FcR with distinct localization in the placental villus as well as CD4 surface expression on human trophoblast cells. In addition, we show that trophoblastic cells interact specifically with the gp120/gp160 viral envelope protein. By their tissue localization, these receptors could be responsible for the entry of HIV into the fetal placental cells. Furthermore, purified placental cells can be directly infected by HIV in vitro, and the infection is inhibited by soluble CD4. This suggests a crucial role of the CD4 receptor but an additional way of entry cannot be excluded. Such an in vitro model may be suitable for further studies concerning placental HIV transmission and its prevention.


Assuntos
Antígenos CD4/análise , HIV-1/crescimento & desenvolvimento , Trofoblastos/microbiologia , Antígenos CD4/fisiologia , Células Cultivadas , Feminino , Humanos , Gravidez , Receptores Fc/análise , Trofoblastos/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...