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1.
World Dev ; 135: 105072, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32834380

RESUMO

This note presents three important facts on the COVID-19 pandemic and 22 developing countries, namely those in the Pacific. First, social protection systems are less common in the Pacific than in the rest of the world, meaning the region is not particularly well equipped to deal with the sharp decline in economic activity associated with the disease and standard policy responses (e.g., lockdowns) without plunging a large share of the population into poverty. Second, aggressive travel restrictions and effective domestic policy responses have spared many Pacific countries from the worst impacts of COVID-19. Ten countries have not had a single confirmed case. The experience of the region thus offers helpful lessons for other developing countries in keeping the crisis at bay. Third, the relative success of Australia and New Zealand in managing the virus provides an opportunity to pilot and test in the region what a carefully managed pathway to allow the tourism, migration, and remittances, that many countries depend on, to begin flowing again. Against its relative success, the Pacific has a unique opportunity to show the world how to safely emerge from the current crisis and address underlying vulnerabilities before the next one.

2.
Ambio ; 48(10): 1195-1208, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30607718

RESUMO

Indonesia's oil palm expansion during the last two decades has resulted in widespread environmental and health damages through land clearing by fire and peat conversion, but it has also contributed to rural poverty alleviation. In this paper, we examine the role that decentralization has played in the process of Indonesia's oil palm development, particularly among independent smallholder producers. We use primary survey information, along with government documents and statistics, to analyze the institutional dynamics underpinning the sector's impacts on economic development and the environment. Our analysis focuses on revenue-sharing agreements between district and central governments, district splitting, land title authority, and accountability at individual levels of government. We then assess the role of Indonesia's Village Law of 2014 in promoting rural development and land clearing by fire. We conclude that both environmental conditionality and positive financial incentives are needed within the Village Law to enhance rural development while minimizing environmental damages.


Assuntos
Política , Planejamento Social , Humanos , Indonésia , População Rural , Solo
3.
Clin Pharmacokinet ; 52(8): 705-12, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23588536

RESUMO

BACKGROUND AND OBJECTIVE: Pentostatin is an irreversible inhibitor of adenosine deaminase and has been used to prevent graft-versus-host disease (GVHD) and to treat both acute and chronic GVHD. Dose reduction equations for patients with renal insufficiency are based on few patients with limited pharmacokinetic and clinical results. This phase II study (NCT00201786) was conducted to assess pentostatin efficacy and infectious complications seen from our previous phase I study in steroid-refractory acute GVHD (aGVHD). PATIENTS AND METHODS: Hospitalized patients with steroid-refractory aGVHD were given pentostatin 1.5 mg/m(2)/day intravenously on days 1-3 of each 14-day cycle. Prior to each dose, dose modifications were based on Cockcroft-Gault estimated creatinine clearance (eCrCL) with 30-50 mL/min/1.73 m(2) leading to a 50 % dose reduction and eCrCL less than 30 mL/min/1.73 m(2) leading to study removal. Plasma pentostatin area under the concentration-time curve (AUC) and incidence of infectious complications were evaluated. RESULTS: Two of the eight patients treated demonstrated excessive pentostatin exposure as determined by measurement of AUC. One of these patients had renal impairment, whereas the other patient demonstrated borderline renal function. Despite dose reduction to 0.75 mg/m(2), AUCs were significantly increased compared to the other patients in this study. Seven of eight patients treated with pentostatin had cytomegalovirus (CMV) viremia after pentostatin treatment; however none developed proven CMV disease. CONCLUSION: A 50 % dose reduction in patients with eCrCL 30-50 mL/min/1.73 m(2) seems reasonable. However, the eCrCL should be interpreted with extreme caution in patients who are critically ill and/or with poor performance status. Renal function assessment based on the Cockcroft-Gault method could be significantly overestimated thus risking pentostatin overdosing. These results imply a need to closely monitor pentostatin exposure in patients with renal insufficiency.


Assuntos
Inibidores de Adenosina Desaminase/administração & dosagem , Inibidores de Adenosina Desaminase/farmacocinética , Doença Enxerto-Hospedeiro/sangue , Pentostatina/administração & dosagem , Pentostatina/farmacocinética , Inibidores de Adenosina Desaminase/sangue , Adulto , Anticorpos Monoclonais/administração & dosagem , Área Sob a Curva , Transfusão de Sangue Autóloga , Creatinina/sangue , Ciclosporina/administração & dosagem , Resistência a Medicamentos , Feminino , Doença Enxerto-Hospedeiro/tratamento farmacológico , Humanos , Imunossupressores/administração & dosagem , Infliximab , Transfusão de Linfócitos , Masculino , Metotrexato/administração & dosagem , Metilprednisolona/uso terapêutico , Pessoa de Meia-Idade , Pentostatina/sangue , Insuficiência Renal/sangue , Insuficiência Renal/tratamento farmacológico , Transplante de Células-Tronco , Tacrolimo/administração & dosagem , Adulto Jovem
4.
Clin Cancer Res ; 18(17): 4600-11, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22791882

RESUMO

PURPOSE: During cell-cycle progression, D-cyclins activate cyclin-dependent kinases (CDKs) 4/6 to inactivate Rb, permitting E2F1-mediated S-phase gene transcription. This critical pathway is typically deregulated in cancer, and novel inhibitory strategies would be effective in a variety of tumors. The protein synthesis inhibitor silvestrol has potent activity in B-cell leukemias via the mitochondrial pathway of apoptosis, and also reduces cyclin D1 expression in breast cancer and lymphoma cell lines. We hypothesized that this dual activity of silvestrol would make it especially effective in malignancies driven by aberrant cyclin D1 expression. EXPERIMENTAL DESIGN: Mantle cell lymphoma (MCL), characterized by elevated cyclin D1, was used as a model to test this approach. The cyclin D/Rb/E2F1 pathway was investigated in vitro using MCL cell lines and primary tumor cells. Silvestrol was also evaluated in vivo using an aggressive model of MCL. RESULTS: Silvestrol showed low nanomolar potency both in MCL cell lines and primary MCL tumor cells. D-cyclins were depleted with just 10 nmol/L silvestrol at 16 hours, with subsequent reductions of phosphorylated Rb, E2F1 protein, and E2F1 target transcription. As showed in other leukemias, silvestrol caused Mcl-1 depletion followed by mitochondrial depolarization and caspase-dependent apoptosis, effects not related to inhibition of CDK4/6. Silvestrol significantly (P < 0.0001) prolonged survival in a MCL xenograft model without detectable toxicity. CONCLUSIONS: These data indicate that silvestrol effectively targets the cyclin/CDK/Rb pathway, and additionally induces cytotoxicity via intrinsic apoptosis. This dual activity may be an effective therapeutic strategy in MCL and other malignancies.


Assuntos
Ciclina D1 , Fator de Transcrição E2F1 , Linfoma de Célula do Manto , Triterpenos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Linhagem Celular Tumoral , Ciclina D1/genética , Ciclina D1/metabolismo , Fator de Transcrição E2F1/genética , Fator de Transcrição E2F1/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Linfoma de Célula do Manto/genética , Linfoma de Célula do Manto/metabolismo , Linfoma de Célula do Manto/patologia , Linfoma de Célula do Manto/terapia , Redes e Vias Metabólicas , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transplante Heterólogo
5.
AAPS J ; 13(3): 357-64, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21538216

RESUMO

Protein synthesis is a powerful therapeutic target in leukemias and other cancers, but few pharmacologically viable agents are available that affect this process directly. The plant-derived agent silvestrol specifically inhibits translation initiation by interfering with eIF4A/mRNA assembly with eIF4F. Silvestrol has potent in vitro and in vivo activity in multiple cancer models including acute lymphoblastic leukemia (ALL) and is under pre-clinical development by the US National Cancer Institute, but no information is available about potential mechanisms of resistance. In a separate report, we showed that intraperitoneal silvestrol is approximately 100% bioavailable systemically, although oral doses were only 1% bioavailable despite an apparent lack of metabolism. To explore mechanisms of silvestrol resistance and the possible role of efflux transporters in silvestrol disposition, we characterized multi-drug resistance transporter expression and function in a silvestrol-resistant ALL cell line generated via culture of the 697 ALL cell line in gradually increasing silvestrol concentrations. This resistant cell line, 697-R, shows significant upregulation of ABCB1 mRNA and P-glycoprotein (Pgp) as well as cross-resistance to known Pgp substrates vincristine and romidepsin. Furthermore, 697-R cells readily efflux the fluorescent Pgp substrate rhodamine 123. This effect is prevented by Pgp inhibitors verapamil and cyclosporin A, as well as siRNA to ABCB1, with concomitant re-sensitization to silvestrol. Together, these data indicate that silvestrol is a substrate of Pgp, a potential obstacle that must be considered in the development of silvestrol for oral delivery or targeting to tumors protected by Pgp overexpression.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/biossíntese , Resistencia a Medicamentos Antineoplásicos , Iniciação Traducional da Cadeia Peptídica/efeitos dos fármacos , Inibidores da Síntese de Proteínas/farmacologia , Triterpenos/farmacologia , Subfamília B de Transportador de Cassetes de Ligação de ATP , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Linhagem Celular Tumoral , Interpretação Estatística de Dados , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras , RNA Interferente Pequeno/farmacologia , Regulação para Cima
6.
PLoS One ; 5(6): e10941, 2010 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-20532179

RESUMO

BACKGROUND: While deacetylase (DAC) inhibitors show promise for the treatment of B-cell malignancies, those introduced to date are weak inhibitors of class I and II DACs or potent inhibitors of class I DAC only, and have shown suboptimal activity or unacceptable toxicities. We therefore investigated the novel DAC inhibitor AR-42 to determine its efficacy in B-cell malignancies. PRINCIPAL FINDINGS: In mantle cell lymphoma (JeKo-1), Burkitt's lymphoma (Raji), and acute lymphoblastic leukemia (697) cell lines, the 48-hr IC(50) (50% growth inhibitory concentration) of AR-42 is 0.61 microM or less. In chronic lymphocytic leukemia (CLL) patient cells, the 48-hr LC(50) (concentration lethal to 50%) of AR-42 is 0.76 microM. AR-42 produces dose- and time-dependent acetylation both of histones and tubulin, and induces caspase-dependent apoptosis that is not reduced in the presence of stromal cells. AR-42 also sensitizes CLL cells to TNF-Related Apoptosis Inducing Ligand (TRAIL), potentially through reduction of c-FLIP. AR-42 significantly reduced leukocyte counts and/or prolonged survival in three separate mouse models of B-cell malignancy without evidence of toxicity. CONCLUSIONS/SIGNIFICANCE: Together, these data demonstrate that AR-42 has in vitro and in vivo efficacy at tolerable doses. These results strongly support upcoming phase I testing of AR-42 in B-cell malignancies.


Assuntos
Linfoma de Burkitt/patologia , Inibidores de Histona Desacetilases/farmacologia , Linfoma de Célula do Manto/patologia , Fenilbutiratos/farmacologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Apoptose , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos , Humanos
7.
Blood ; 113(19): 4656-66, 2009 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-19190247

RESUMO

Therapeutic options for advanced B-cell acute lymphoblastic leukemia (ALL) and chronic lymphocytic leukemia (CLL) are limited. Available treatments can also deplete T lymphocytes, leaving patients at risk of life-threatening infections. In the National Cancer Institute cell line screen, the structurally unique natural product silvestrol produces an unusual pattern of cytotoxicity that suggests activity in leukemia and selectivity for B cells. We investigated silvestrol efficacy using primary human B-leukemia cells, established B-leukemia cell lines, and animal models. In CLL cells, silvestrol LC(50) (concentration lethal to 50%) is 6.9 nM at 72 hours. At this concentration, there is no difference in sensitivity of cells from patients with or without the del(17p13.1) abnormality. In isolated cells and whole blood, silvestrol is more cytotoxic toward B cells than T cells. Silvestrol causes early reduction in Mcl-1 expression due to translational inhibition with subsequent mitochondrial damage, as evidenced by reactive oxygen species generation and membrane depolarization. In vivo, silvestrol causes significant B-cell reduction in Emu-Tcl-1 transgenic mice and significantly extends survival of 697 xenograft severe combined immunodeficient (SCID) mice without discernible toxicity. These data indicate silvestrol has efficacy against B cells in vitro and in vivo and identify translational inhibition as a potential therapeutic target in B-cell leukemias.


Assuntos
Linfócitos B/efeitos dos fármacos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Triterpenos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linfócitos B/metabolismo , Western Blotting , Deleção Cromossômica , Cromossomos Humanos Par 17/genética , Feminino , Humanos , Técnicas In Vitro , Leucemia Linfocítica Crônica de Células B/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos SCID , Camundongos Transgênicos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Proteína de Sequência 1 de Leucemia de Células Mieloides , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Proteínas Proto-Oncogênicas/fisiologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de Sobrevida , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Transplante Heterólogo
8.
Blood ; 108(4): 1334-8, 2006 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-16670263

RESUMO

Drug development in human chronic lymphocytic leukemia (CLL) has been limited by lack of a suitable animal model to adequately assess pharmacologic properties relevant to clinical application. A recently described TCL-1 transgenic mouse develops a chronic B-cell CD5(+) leukemia that might be useful for such studies. Following confirmation of the natural history of this leukemia in the transgenic mice, we demonstrated that the transformed murine lymphocytes express relevant therapeutic targets (Bcl-2, Mcl-1, AKT, PDK1, and DNMT1), wild-type p53 status, and in vitro sensitivity to therapeutic agents relevant to the treatment of human CLL. We then demonstrated the in vivo clinical activity of low-dose fludarabine in transgenic TCL-1 mice with active leukemia. These studies demonstrated both early reduction in blood-lymphocyte count and spleen size and prolongation of survival (P = .046) compared with control mice. Similar to human CLL, an emergence of resistance was noted with fludarabine treatment in vivo. Overall, these studies suggest that the TCL-1 transgenic leukemia mouse model has similar clinical and therapeutic response properties to human CLL and may therefore serve as a useful in vivo tool to screen new drugs for subsequent development in CLL.


Assuntos
Antineoplásicos/farmacologia , Transformação Celular Neoplásica/genética , Leucemia Linfocítica Crônica de Células B/genética , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas Proto-Oncogênicas/genética , Vidarabina/análogos & derivados , Animais , Antineoplásicos/uso terapêutico , Antígenos CD5/metabolismo , Transformação Celular Neoplásica/efeitos dos fármacos , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Leucemia Linfocítica Crônica de Células B/sangue , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Camundongos , Camundongos Transgênicos , Proteínas de Neoplasias/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Células Tumorais Cultivadas , Vidarabina/farmacologia , Vidarabina/uso terapêutico
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