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1.
Oncogene ; 21(29): 4473-80, 2002 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-12085225

RESUMO

The Epstein-Barr virus (EBV) transforms B cells in part by inhibiting the cellular apoptotic programme. This is also observed when Burkitt lymphoma cell lines are infected with EBV. Induction of apoptosis is one of the mechanisms by which fludarabine inhibits the growth of cells with low proliferative capacity. This compound can also inhibit several other mechanisms in the cell, including inhibition of the synthesis of factors such as STAT1. To analyse the relationship between EBV status, fludarabine-induced apoptosis, and transcription factors we studied the EBV-negative Burkitt lymphoma cell line BL2, its EBV-infected counterpart BL2.B95.8 and the EBV-transformed cell line PRI. The BL2 cell line was found to be very sensitive to fludarabine. The BL2.B95.8 and PRI cells were both resistant but the latter to a lesser extent. In the PRI cells fludarabine activated p53, but not in the BL2.B95.8 cells in which the p53 pathway is inactivated. We observed that this inactivation results in part from the lack of expression of the MDM2 inhibitor p14ARF. Conversely, there was a substantial constitutive activation of STAT1, and not of the other STATs, in the BL2.B95.8 cells and a modest one in the PRI cells. Furthermore, expression of STAT1 was significantly reduced by fludarabine treatment in the PRI cells, but not in the BL2.BL95.8 cells. Finally, the expression of p21WAF1/CIP1 was detected only in the BL2.B95.8 and PRI cells. This protein, known to play a role in cell survival, may therefore be involved in the resistance of the BL2.B95.8 cells to fludarabine.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Linfócitos B/efeitos dos fármacos , Linfócitos B/virologia , Resistencia a Medicamentos Antineoplásicos , Herpesvirus Humano 4/fisiologia , Vidarabina/farmacologia , Linfócitos B/patologia , Western Blotting , Linhagem Celular , DNA/metabolismo , Proteínas de Ligação a DNA/metabolismo , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Reação em Cadeia da Polimerase , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fator de Transcrição STAT1 , Transativadores/metabolismo , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/metabolismo , Vidarabina/análogos & derivados
2.
Clin Infect Dis ; 40(8): 1141-7, 2005 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15791514

RESUMO

UNLABELLED: BACKGROUND; Bone aspergillosis remains a rare but potentially devastating fungal disease. Although voriconazole is effective for invasive pulmonary aspergillosis, evidence of its efficacy for aspergillosis located in bone is limited. METHODS: We report our experience with voriconazole in 4 cases of invasive bone aspergillosis. In addition, all cases of probable and definite bone aspergillosis from the Pfizer clinical database were reviewed and analyzed to determine the safety and efficacy of voriconazole treatment. Global response was evaluated at the end of therapy on the basis of a composite assessment of overall clinical, radiological, and mycological responses. RESULTS: Twenty patients are described, of whom 18 had definite bone involvement diagnosed (spondylodiskitis in 9, sternum/rib osteomyelitis in 6, and peripheral bone involvement in 5). Of 20 patients, 14 were immunocompromised. Oral or intravenous voriconazole was given as salvage therapy for 18 patients; 2 patients received voriconazole as first-line therapy. Median duration of voriconazole treatment was 83.5 days (range, 4-395 days). Global response at end of therapy was satisfactory in 11 (55%) of 20 patients, including complete responses in 4 patients and partial responses in 7 patients; there were no relapses of infection in the 4 patients with complete response to therapy with voriconazole. Treatment was generally well tolerated. CONCLUSIONS: Long-term voriconazole treatment is a new therapeutic option for invasive aspergillosis with bone involvement.


Assuntos
Aspergilose/tratamento farmacológico , Osteíte/tratamento farmacológico , Osteomielite/tratamento farmacológico , Pirimidinas/uso terapêutico , Espondilite/tratamento farmacológico , Triazóis/uso terapêutico , Adolescente , Adulto , Idoso , Antifúngicos/efeitos adversos , Antifúngicos/uso terapêutico , Pré-Escolar , Humanos , Pessoa de Meia-Idade , Osteíte/microbiologia , Osteomielite/microbiologia , Pirimidinas/efeitos adversos , Terapia de Salvação , Espondilite/microbiologia , Triazóis/efeitos adversos , Voriconazol
3.
Liver Transpl ; 13(10): 1422-7, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17902128

RESUMO

Hepatitis C virus (HCV) has been proposed to have immunomodulatory effects in transplant recipients and may promote herpesvirus reactivation. To assess this, we compared the incidence of herpesvirus reactivation in HCV-positive and HCV-negative liver transplant recipients. Quantitative viral load testing was performed at regular intervals posttransplantation for cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesviruses (HHV) 6, 7, and 8, and varicella zoster virus (VZV) in 177 liver transplant patients who were HCV-positive (n=60) or HCV-negative (n=117). The incidence of CMV disease, CMV viremia, and the peak CMV viral load was not significantly different in HCV-positive vs. HCV-negative patients. Similarly, no differences in HHV-6 or EBV reactivation were observed. HHV-8 or VZV viremia was not detected in any patient in the study. A lower incidence of HHV-7 infection occurred in HCV-positive patients vs. HCV-negative patients (47.6% vs. 72.7%; P=0.006). In conclusion, these results suggest that HCV infection does not appear to promote herpesvirus reactivation after liver transplantation.


Assuntos
Hepacivirus/imunologia , Hepatite C/virologia , Infecções por Herpesviridae/virologia , Herpesviridae/fisiologia , Transplante de Fígado , Ativação Viral/fisiologia , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Hepatite C/epidemiologia , Anticorpos Anti-Hepatite C/imunologia , Infecções por Herpesviridae/epidemiologia , Humanos , Incidência , Falência Hepática/cirurgia , Masculino , Pessoa de Meia-Idade , Carga Viral , Replicação Viral/fisiologia
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