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1.
Support Care Cancer ; 23(7): 1987-95, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25516211

RESUMO

INTRODUCTION: Currently, very few guidelines for supportive care for children with cancer exist. In the Netherlands, nationwide guidelines are over 10 years old and mostly based on expert opinion. Consequently, there is growing support and need for clinical practice guidelines (CPGs), which ought to be developed with a well-defined methodology and include a systematic search of literature, evidence summaries, and a transparent description of the decision process for the final recommendations. Development of CPGs is time consuming; therefore, it is important to prioritize topics for which there is the greatest clinical demand. OBJECTIVES: This study aims to prioritize childhood cancer supportive care topics for development of CPGs. METHODS: A Delphi survey consisting of two rounds was conducted to prioritize relevant childhood cancer supportive care topics for the development of CPGs. A group of experts comprising 15 pediatric oncologists, 15 pediatric oncology nurses, and 15 general pediatricians involved in care for childhood cancer patients were invited to participate. All relevant supportive care topics in childhood cancer were rated. RESULTS: In both rounds, 36 panellists (82%) responded. Agreement between panellists was very good, with an intraclass correlation coefficient of 0.918 (95% confidence interval (CI) = 0.849-0.966, p < 0.001) in round 2. The ten topics with the highest score in the final round were infection, sepsis, febrile neutropenia, pain, nausea/vomiting, restrictions in daily life and activities, palliative care, procedural sedation, terminal care, and oral mucositis. CONCLUSION: We successfully used a Delphi survey to prioritize childhood cancer supportive care topics for the development of CPGs. This is a first step towards uniform and evidence-based Dutch guidelines in supportive care in childhood cancer. Even though performed nationally, we believe that this study can also be regarded as an example starting point for international development of CPGs in the field of supportive care in cancer or any other field for that matter.


Assuntos
Técnica Delphi , Oncologia/normas , Neoplasias/terapia , Cuidados Paliativos/normas , Pediatria/normas , Guias de Prática Clínica como Assunto , Criança , Necessidades e Demandas de Serviços de Saúde , Humanos , Oncologia/métodos , Países Baixos , Cuidados Paliativos/métodos , Pediatria/métodos
2.
Transpl Infect Dis ; 16(2): 188-94, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24438482

RESUMO

BACKGROUND AND AIMS: Varicella zoster virus (VZV) reactivation following hematopoietic stem cell transplantation (HSCT) may cause significant morbidity and mortality. We undertook a retrospective study to determine the frequency and risk factors associated with VZV reactivation, including underlying disease, the use of fludarabine in high-risk leukemia chemotherapy protocols, and immune status before HSCT. PATIENTS AND METHODS: We studied 163 children who underwent a first HSCT between 2002 and 2008, before introduction of routine VZV prophylaxis on our unit. VZV diagnosis was based on clinical features and supported by polymerase chain reaction on plasma and/or vesical fluid. Patient data and possible risk factors pre- and post HSCT were recorded and compared using a multivariate regression analysis. RESULTS: Within this cohort, 41 (25%) patients developed VZV reactivation during the first year after transplantation at a median of 60 days post HSCT. VZV reactivation occurred more often within the subgroup of patients with acute leukemia compared with the remainder of patients (38% vs. 15%, P < 0.01). Multivariate Cox regression analysis revealed that, besides positive VZV serology in patients pre-HSCT (P = 0.03), acute leukemia as the indication for HSCT remained the only independent risk factor for VZV reactivation (P = 0.025, odds ratio 2.5, 95% confidence interval 1.1-5.6). This was associated with low pre-transplant T-cell counts, especially in the CD4(+) subset. No differences were found in relation to donor type, age, or use of serotherapy. CONCLUSION: VZV reactivation after HSCT predominates in acute leukemia patients and is associated with low T CD4(+) lymphocyte counts. This finding demonstrates the impact of pre-HSCT host immune suppression on VZV reactivation patterns after HSCT.


Assuntos
Antineoplásicos/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Herpesvirus Humano 3/fisiologia , Terapia de Imunossupressão/efeitos adversos , Vidarabina/análogos & derivados , Ativação Viral/imunologia , Adolescente , Contagem de Linfócito CD4 , Criança , Pré-Escolar , Humanos , Imunidade Celular/imunologia , Lactente , Leucemia Mieloide Aguda/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Estudos Retrospectivos , Linfócitos T/imunologia , Vidarabina/efeitos adversos , Adulto Jovem
3.
Psychooncology ; 21(2): 168-75, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22271537

RESUMO

UNLABELLED: Hematopoietic stem cell transplantation is an effective therapy for life-threatening hematological diseases. Parents may be asked to donate hematopoietic stem cells for their child when no compatible related or unrelated donor is available. OBJECTIVE: Parents donating G-CSF mobilized peripheral blood stem cells simultaneously and uniquely fulfill the dual role of donor and caregiver for their ill child. The experiences of both sibling and unrelated stem cell donors have been extensively reported but not those of parental donors. METHODS: We therefore undertook a study specifically to investigate the experiences and coping strategies of parental stem cell donors. In-depth qualitative interviews were conducted with 13 parental donors, which were subsequently transcribed and subjected to thematic analysis. In addition, parental coping was assessed utilizing the Utrecht Coping List. RESULTS: Qualitative analyses revealed four main thematic categories describing the way parental stem cell donation was experienced, namely 'Hope and Fear', 'Need for Information', 'Do Anything for your Child' and 'Transplant Outcome' In addition parents noted similar difficulties which were unrelated to their specific role as a donor, for example they felt socially isolated. CONCLUSIONS: Individual information for the parents needs to address not only the transplantation procedure but particularly those aspects related to the donation process. We feel there is a need for a protocol specifically designed to support and coach parental donors.


Assuntos
Cuidadores/psicologia , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Mobilização de Células-Tronco Hematopoéticas , Transplante de Células-Tronco Hematopoéticas , Pais/psicologia , Doadores de Tecidos/psicologia , Adaptação Psicológica , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Haplótipos , Mobilização de Células-Tronco Hematopoéticas/métodos , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Hospitais de Ensino , Humanos , Lactente , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Neoplasias/cirurgia , Países Baixos , Pesquisa Qualitativa , Fatores Socioeconômicos , Transplante Homólogo
4.
Transfus Apher Sci ; 41(1): 73-6, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19525147

RESUMO

G-CSF/dexamethasone stimulated donor derived granulocyte transfusion (GTX) has been shown in non-randomized studies to be a useful co-therapy in immune-compromised patients unresponsive to conventional antimicrobial treatments. Reports of GTX are however usually single institution adult experiences. Substantiated pediatric data, other than in neonates, is less common.


Assuntos
Granulócitos/transplante , Adulto , Criança , Humanos , Hospedeiro Imunocomprometido/fisiologia , Recém-Nascido , Consentimento Livre e Esclarecido , Países Baixos , Neutropenia/terapia , Seleção de Pacientes , Guias de Prática Clínica como Assunto , Sistema de Registros
5.
Bone Marrow Transplant ; 41 Suppl 2: S58-64, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18545246

RESUMO

Allogeneic hematopoietic SCT (HSCT) is an established treatment for some children with life-threatening hematological disease, immune deficiencies and inborn errors of metabolism. Despite advances in prevention and post transplant immuno-suppressive strategies, acute GvHD (aGvHD) remains a major cause of morbidity and mortality in children undergoing SCT. Although reported incidence rates differ, it has been estimated that, depending upon the patient and donor cohort studied, 20-50% of all transplanted patients will experience grade 2 or more aGvHD despite immuno-suppressive prophylaxis. aGvHD occurs when transplanted donor T lymphocytes recognize antigenic disparities between the host and recipient. Pathways other than direct T-cell-mediated cytotoxicity have been shown to be important in the pathogenesis. Inflammatory cytokine release has been implicated as the primary mediator of aGvHD and activation of T cells is one step in the complex process. Deregulated cytokine release by cells other than T cells leads to tissue damage associated with aGvHD. GvHD is a factor that compromises the overall success rate of allogeneic HSCT and remains a challenge, which, in turn, requires an understanding of the pathophysiology, clinical presentation and management of this complication. The authors concentrate on the most recent knowledge of the pathogenesis as well as the classification of aGvHD.


Assuntos
Doença Enxerto-Hospedeiro/genética , Doença Enxerto-Hospedeiro/fisiopatologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Criança , Predisposição Genética para Doença/genética , Doença Enxerto-Hospedeiro/imunologia , Humanos , Imunidade Celular/imunologia , Polimorfismo de Nucleotídeo Único/genética , Transplante Homólogo
6.
Int J STD AIDS ; 29(2): 185-194, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28750577

RESUMO

Malawi launched Option B+, a program for all pregnant or breastfeeding HIV-positive women to begin lifelong combination antiretroviral therapy (cART), in July 2011. This study characterises a portion of the continuum of care within an antenatal setting in Lilongwe. Women testing HIV-positive and having a cART initiation record at Bwaila Antenatal Clinic from July 2013 to January 2014 were included. Using logistic regression models, we analysed relationships between maternal characteristics and return for infant testing. Among 490 HIV-positive women with a cART initiation record, 360 (73%) were retained at three months. Of these, 203 (56%) were adherent. Records of infant testing were located for 204 women (42%). Women who were not retained were less likely to have an early infant diagnosis record (aOR = 0.20; 95% CI: 0.10, 0.41). Among the women retained, there was a non-significant association between maternal adherence and infant testing (OR = 1.35; 95% CI: 0.89, 2.06). Women lost at earlier continuum stages, who are at higher risk for mother-to-child-transmission, were less likely to bring infants for testing. Even with a test-and-treat program, many women did not remain in care or bring their infant for testing. Facilitating strategies to improve these measures remains an important unmet need.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Continuidade da Assistência ao Paciente , Infecções por HIV/tratamento farmacológico , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Cooperação do Paciente/estatística & dados numéricos , Pacientes Desistentes do Tratamento/estatística & dados numéricos , Complicações Infecciosas na Gravidez/tratamento farmacológico , Avaliação de Programas e Projetos de Saúde/métodos , Adulto , Aleitamento Materno , Feminino , Seguimentos , Infecções por HIV/prevenção & controle , Infecções por HIV/transmissão , Soropositividade para HIV/tratamento farmacológico , Humanos , Lactente , Recém-Nascido , Perda de Seguimento , Malaui , Avaliação de Processos e Resultados em Cuidados de Saúde , Cooperação do Paciente/psicologia , Gravidez , Cuidado Pré-Natal/psicologia , Cuidado Pré-Natal/estatística & dados numéricos , Estudos Retrospectivos , Adulto Jovem
7.
Bone Marrow Transplant ; 52(7): 984-988, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28319079

RESUMO

Permanent alopecia after haematopoietic stem cell transplantation (HSCT) is distressing and few studies have investigated this late effect. The aim of the study was to assess the percentage of patients with alopecia and investigate risk factors for alopecia. Patients who underwent allogeneic HSCT before age 19 years, from January 1990 to January 2013, who were at least 2 years after transplant and in follow-up in our clinic were included. Alopecia was defined as clinically apparent decreased hair density. Possible risk factors considered for alopecia after HSCT included: gender, age, diagnosis, donor type, conditioning regimen: cranial irradiation (TBI/cranial radiotherapy) and/or chemotherapy, which chemotherapeutic agents were used and acute/chronic GvHD. The percentage of permanent alopecia in our cohort was 15.6% (41/263 patients). All patients had diffuse alopecia except for one with alopecia totalis. In multivariate analysis, a conditioning regimen with busulphan and busulphan plus fludarabine (odds ratio (OR) 5.7 (confidence interval (CI): 2.5-12.7) and OR 7.4 (CI: 3.3-16.2), respectively, was the main risk factor and associated with alopecia independent of acute/chronic GvHD. Neither TBI nor other alkylating chemotherapy, including treosulfan, was associated with alopecia. In conclusion, permanent alopecia after HSCT is associated with busulphan and GvHD and occurs in 16% of patients.


Assuntos
Alopecia/epidemiologia , Bussulfano/efeitos adversos , Neoplasias Hematológicas/terapia , Transplante de Células-Tronco Hematopoéticas , Condicionamento Pré-Transplante/efeitos adversos , Vidarabina/análogos & derivados , Doença Aguda , Adolescente , Adulto , Alopecia/etiologia , Alopecia/patologia , Bussulfano/administração & dosagem , Criança , Pré-Escolar , Estudos Transversais , Feminino , Seguimentos , Doença Enxerto-Hospedeiro/epidemiologia , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/patologia , Neoplasias Hematológicas/epidemiologia , Neoplasias Hematológicas/patologia , Humanos , Lactente , Masculino , Fatores de Risco , Condicionamento Pré-Transplante/métodos , Vidarabina/administração & dosagem , Vidarabina/efeitos adversos
8.
Ned Tijdschr Geneeskd ; 161: D857, 2017.
Artigo em Holandês | MEDLINE | ID: mdl-28294926

RESUMO

Every child with a life-limiting or threatening illness, and his or her family, has a right to palliative care. Palliative care is not limited to end-of-life care, but starts from the moment of diagnosis and is independent of whether there are curative options. To optimise quality of life of both the child and the family, the emphasis of care should be on both somatic and psychosocial and spiritual aspects from the very start, and goals should be set together with the child and the family. A multidisciplinary and pro-active approach is essential if this is to be achieved. It is, therefore, strongly recommended that at least every academic hospital should have a multidisciplinary paediatric palliative care team.


Assuntos
Cuidados Paliativos , Equipe de Assistência ao Paciente/organização & administração , Qualidade de Vida , Assistência Terminal/métodos , Criança , Humanos , Lactente , Comunicação Interdisciplinar , Masculino
9.
Bone Marrow Transplant ; 35 Suppl 1: S35-8, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15812528

RESUMO

For many children with life-threatening hematological diseases, hematopoietic stem cell transplantation (HSCT) is the only curative option. In children lacking a matched related or unrelated donor and with the certainty that, left untreated, death will ensue alternative donors must be sought. Haplo-identical peripheral blood stem cell transplantation (PBSCT) from a healthy parent is a feasible alternative. To reduce the risk of fatal graft-versus-host disease (GvHD) as a complication of transplant across major histocompatibility antigens, intense T-cell depletion is required. Large numbers of purified, cytokine mobilized peripheral stem cells (the so-called mega-dose concept) are required to compensate for the significantly increased risk of either graft failure or early rejection. In our unit, despite this approach, graft dysfunction has, in a significant group of children, proved problematic and, despite salvage attempts at re-transplantation, usually fatal. In children with hematological malignant disease, our overall relapse-free survival is 41%. However, successful transplant outcome has been associated with considerable delays in immune reconstitution that can be implicated in subsequent viral reactivation. We are investigating new strategies to improve the outcome of haplo-identical PBSCT, which may allow us to offer this form of treatment to more children requiring urgent HSCT.


Assuntos
Rejeição de Enxerto , Doenças Hematológicas/terapia , Sistema Imunitário , Transplante de Células-Tronco de Sangue Periférico , Recuperação de Função Fisiológica , Adolescente , Antígenos CD34 , Criança , Pré-Escolar , Feminino , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/mortalidade , Doença Enxerto-Hospedeiro/prevenção & controle , Doenças Hematológicas/mortalidade , Humanos , Lactente , Depleção Linfocítica/métodos , Masculino , Transplante de Células-Tronco de Sangue Periférico/mortalidade , Terapia de Salvação/métodos , Terapia de Salvação/mortalidade , Linfócitos T/imunologia
10.
Bone Marrow Transplant ; 35(5): 455-61, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15654356

RESUMO

Juvenile myelomonocytic leukemia (JMML) is a childhood leukemia for which allogeneic BMT is the only curative therapy. At our pediatric stem cell transplantation unit, we performed 26 BMTs in 23 children (age 0.5-12.7 years). Conditioning was CY/TBI based (1980-1996, n=14) or BU/CY/melphalan based (1996-2001, n=9). Donors were HLA-identical siblings (n=11), unrelated volunteers (n=9) or mismatched family members (n=3). A total of 10 patients survive in CR (median follow-up 6.8 years, range 3.1-22.2 years). Relapse or persistent disease was observed in eight and two patients, respectively. Nine of these patients died, one achieved a second remission following acute nonlymphatic leukemia chemotherapy (duration to date 5.3 years). Transplant-related mortality occurred in four patients. Overall survival at 5 and 10 years was 43.5%. Using T-cell-depleted, one-antigen mismatched unrelated donors was the only significant adverse factor associated with relapse in multivariate analysis (P=0.039, hazard ratio 4.9). Together with a trend towards less relapse in patients with graft-versus-host-disease and in patients transplanted with matched unrelated donors, this suggests a graft-versus-leukemia effect of allogeneic BMT in JMML.


Assuntos
Transplante de Medula Óssea/métodos , Leucemia Mielomonocítica Crônica/terapia , Transplante de Medula Óssea/mortalidade , Criança , Pré-Escolar , Feminino , Doença Enxerto-Hospedeiro , Efeito Enxerto vs Leucemia , Histocompatibilidade , Humanos , Lactente , Leucemia Mielomonocítica Crônica/mortalidade , Depleção Linfocítica , Masculino , Análise Multivariada , Recidiva , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida , Condicionamento Pré-Transplante/métodos , Condicionamento Pré-Transplante/mortalidade , Transplante Homólogo , Resultado do Tratamento
11.
Bone Marrow Transplant ; 35(1): 17-23, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15502853

RESUMO

We studied the pharmacokinetics of intravenous busulfan (Bu) in children in order to further optimize intravenous Bu dosing in relation to toxicity and survival. A total of 31 children undergoing Bu-based conditioning for allogeneic SCT were enrolled in a study. The starting dose was 1.0 mg/kg (age < 4 years) and 0.8 mg/kg (age > or =4 years), four doses per day during 4 days. Dose adjustment was allowed up to a maximum dose of 1.0 mg/kg per dose if the target area under the serum concentration-time curve (AUC) was not reached. Pharmacokinetic studies were performed after the first dose. Donor engraftment was established in 28 out of 31 patients. The average AUC after the first dose was the same in children < 4 years as in children > or =4 years. Mean clearance was higher in children < 4 years than in children > or =4 years. In 35% of all patients, total AUC was within the target AUC. The other children's AUCs were below the target range. No relationships were found between systemic exposure to Bu and toxicity or clinical outcome. We concluded that, in accordance with previous data, within the observed AUCs no clear relationship was observed between Bu AUC and outcome with respect to toxicity, engraftment and relapse.


Assuntos
Bussulfano/administração & dosagem , Transplante de Células-Tronco/métodos , Condicionamento Pré-Transplante , Adolescente , Área Sob a Curva , Bussulfano/farmacocinética , Bussulfano/toxicidade , Criança , Pré-Escolar , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Feminino , Hepatopatia Veno-Oclusiva/prevenção & controle , Humanos , Imunossupressores/administração & dosagem , Imunossupressores/farmacocinética , Imunossupressores/toxicidade , Lactente , Infusões Intravenosas , Fígado/efeitos dos fármacos , Masculino , Fatores de Tempo , Transplante Homólogo/métodos , Resultado do Tratamento
12.
Stem Cell Res ; 14(2): 198-210, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25679997

RESUMO

Pediatric myelodysplastic syndrome (MDS) is a heterogeneous disease covering a spectrum ranging from aplasia (RCC) to myeloproliferation (RAEB(t)). In adult-type MDS there is increasing evidence for abnormal function of the bone-marrow microenvironment. Here, we extensively studied the mesenchymal stromal cells (MSCs) derived from children with MDS. MSCs were expanded from the bone-marrow of 17 MDS patients (RCC: n=10 and advanced MDS: n=7) and pediatric controls (n=10). No differences were observed with respect to phenotype, differentiation capacity, immunomodulatory capacity or hematopoietic support. mRNA expression analysis by Deep-SAGE revealed increased IL-6 expression in RCC- and RAEB(t)-MDS. RCC-MDS MSC expressed increased levels of DKK3, a protein associated with decreased apoptosis. RAEB(t)-MDS revealed increased CRLF1 and decreased DAPK1 expressions. This pattern has been associated with transformation in hematopoietic malignancies. Genes reported to be differentially expressed in adult MDS-MSC did not differ between MSC of pediatric MDS and controls. An altered mRNA expression profile, associated with cell survival and malignant transformation, of MSC derived from children with MDS strengthens the hypothesis that the micro-environment is of importance in this disease. Our data support the understanding that pediatric and adult MDS are two different diseases. Further evaluation of the pathways involved might reveal additional therapy targets.


Assuntos
Células-Tronco Mesenquimais/fisiologia , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/patologia , Adolescente , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Células Cultivadas , Criança , Pré-Escolar , Citogenética/métodos , Feminino , Humanos , Técnicas In Vitro , Lactente , Masculino , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/patologia , Síndromes Mielodisplásicas/metabolismo , Transcriptoma
13.
J Med Chem ; 34(2): 546-9, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1995875

RESUMO

The possibility of bay-region activation of the cyclopenta PAH (polycyclic aromatic hydrocarbon with a peripherally fused cyclopenta ring) benz[j]aceanthrylene (1) was investigated by synthesis and bioassay of the bay-region metabolites trans-9,10-dihydroxy-9,10-dihydrobenz[j]aceanthrylene (4), trans-9,10-dihydroxy-anti-7,8-epoxy-7,8,9,10-tetrahydrobenz[j]a ceanthrylene (2), and 9,10-dihydrobenz[j]aceanthrylene 9,10-oxide (3). The known 1,2-dihydrobenz[j]aceanthrylene-9,10-dione (5) was obtained by published methods; however, the direct route to target dihydrodiol 4, dehydrogenation of the saturated five-membered ring of 5 followed by NaBH4 reduction, gave a poor yield of 4 contaminated with tetrahydrogenated products. Acceptable yields of 4 were obtained by reduction of 5 to the corresponding tetrahydro diol, diacetylation of the diol, and dehydrogenation of the five-membered ring followed by base-catalyzed deacetylation to 4. anti-Diol epoxide 2 was generated by m-chloroperoxybenzoic acid oxidation of 4. Oxide 3 was synthesized by treatment of the monotosylate of 4 with NaOH in monoglyme. Diol epoxide 2 was an active mutagen in Salmonella typhimurium strain TA98 in the absence of metabolic activation, 3 showed marginal activity, while 3 and 4 were mutagenic with metabolic activation. These results coupled with previous studies support activation of benz[j]aceanthrylene via both 2 and cyclopenta ring epoxidation.


Assuntos
Metilcolantreno/síntese química , Mutagênicos/síntese química , Animais , Metilcolantreno/metabolismo , Metilcolantreno/toxicidade , Testes de Mutagenicidade , Mutagênicos/metabolismo , Mutagênicos/toxicidade , Ratos , Salmonella typhimurium/efeitos dos fármacos
14.
Cancer Lett ; 74(1-2): 25-30, 1993 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-8287368

RESUMO

Cyclopenta-fused homologs of polycyclic aromatic hydrocarbons (PAH) have proven to be more genotoxic and tumorigenic than their parent PAHs. In an effort to uncover their mechanisms of metabolic activation, the morphological transforming activities of dibenzo[k,mno]acephenanthrylene (CP(3,4)B[a]P), dibenzo[j,mno]acephenanthrylene (CP(1,12)B[a]P) and naphtho[1,2,3,4-mno]acephenanthrylene (CPB[e]P) were studied in C3H10T1/2CL8 mouse embryo fibroblasts. CP(3,4)B[a]P, a PAH with a blocked K region and unblocked bay region, was highly active inducing an average of 1.1 Type II and III foci/dish at 5 micrograms/ml with an average of 67% of the dishes containing foci. This activity was similar to that of benzo[a]pyrene. CP(1,12)B[a]P and CPB[e]P were inactive. The relative positions of the cyclopenta-ring and bay region may play an essential role in the metabolic activation of these PAHs and their biological activities.


Assuntos
Benzopirenos/toxicidade , Transformação Celular Neoplásica/metabolismo , Fibroblastos/efeitos dos fármacos , Mutagênicos/toxicidade , Compostos Policíclicos/toxicidade , Poluentes Atmosféricos/metabolismo , Poluentes Atmosféricos/toxicidade , Análise de Variância , Animais , Benzo(a)pireno/análogos & derivados , Benzo(a)pireno/metabolismo , Benzo(a)pireno/toxicidade , Benzopirenos/metabolismo , Biotransformação , Linhagem Celular Transformada , Metilcolantreno/análogos & derivados , Metilcolantreno/metabolismo , Metilcolantreno/toxicidade , Camundongos , Camundongos Endogâmicos C3H , Testes de Mutagenicidade , Compostos Policíclicos/metabolismo , Relação Estrutura-Atividade
15.
Cancer Lett ; 22(3): 255-62, 1984 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-6713366

RESUMO

The mutagenicity of 1-nitropyrene metabolites from rabbit lung S9 incubates was evaluated using the Salmonella typhimurium plate incorporation assay with strain TA98, with and without Aroclor-induced rat liver S9. The following metabolites were isolated, identified and quantitated by HPLC: 1-nitropyrene -4,5- or -9,10-dihydrodiol (K-DHD), N-acetyl-1-aminopyrene ( NAAP ), 1-aminopyrene (1-AMP), 10-hydroxy-1-nitropyrene, 4-, 5-, 6-, 8- or 9-monohydroxy-1-nitropyrene (phenols) and 3-hydroxy-1-nitropyrene. The predominant metabolites formed by lung S9 incubates were K-DHD, 3-OH-1-nitropyrene and phenols. All of the metabolites were mutagenic in the absence of the exogenous rat liver S9 metabolic activation system, and several, including two unidentified metabolites were more potent than the parent 1-nitropyrene. The mutagenicity of 3 of the metabolites ( NAAP , 10-OH-1-nitropyrene and phenols) were enhanced by S9 while most of the other metabolites were less mutagenic in the presence of S9. These results indicate that lung tissue is capable of both oxidative and reductive metabolism which produced mutagenic metabolites, several of which were more potent than the parent compound, 1-NP.


Assuntos
Pulmão/metabolismo , Mutagênicos/metabolismo , Pirenos/metabolismo , Animais , Biotransformação , Técnicas In Vitro , Masculino , Testes de Mutagenicidade , Oxirredução , Pirenos/toxicidade , Coelhos
16.
Cancer Lett ; 19(3): 241-6, 1983 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6883310

RESUMO

Binding of 1-nitro[14C]pyrene (1-NP) or its metabolites to cellular DNA and protein in cultures of rabbit alveolar macrophages and lung and tracheal tissues was examined. DNA binding was highest in tracheal tissue (136.9 +/- 18.3 pmol 1-NP/mg DNA). DNA binding in macrophages and lung tissue was one-fifth of the level observed in tracheal tissue. Also, 1-NP was bound to cellular protein in tracheal and lung tissues, and at a lower level in macrophages. Co-cultivation of the macrophages with lung and tracheal tissues decreased the DNA binding in tracheal tissue and increased the protein binding in macrophages. This study shows that lung cells and tissue are capable of binding 1-NP or its metabolites to DNA and protein.


Assuntos
DNA/metabolismo , Pulmão/metabolismo , Macrófagos/metabolismo , Proteínas/metabolismo , Pirenos/metabolismo , Traqueia/metabolismo , Animais , Radioisótopos de Carbono , Células Cultivadas , Cinética , Masculino , Coelhos
17.
Environ Health Perspect ; 62: 193-6, 1985 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-4085423

RESUMO

The recently characterized environmental mutagen and potential carcinogen 1-nitropyrene (NP) is known to bind DNA in Salmonella typhimurium, and also in anaerobic incubations catalyzed by purified xanthine oxidase. In this study we show that rat liver S9 supernatant, microsomal and cytosolic subcellular fractions are also able to catalyze the binding of 1-nitropyrene labeled with 14C to calf thymus DNA in vitro. In incubations conducted under air, S9 and microsomes from Charles River CD rats were the most active fractions, and NADPH was required for maximum activity (25-100 pmole NP bound/mg DNA/mg protein in 1 hr). S9 and microsomes had about one-fourth the activity under nitrogen, although less of this activity was NADPH-dependent. Binding in cytosolic incubations was generally low (1 to 5 pmole NP/mg DNA/mg protein in 1 hr), was somewhat enhanced under N2, and was more extensive in the absence of NADPH. Treatment of rats (Harlan Sprague-Dawley) with the inducing agents phenobarbital (PB), Aroclor 1254 (A), or 3-methylcholanthrene (3-MC) enhanced NADPH-dependent binding in aerobic S9 (2- to 5-fold) and microsomal (10- to 20-fold) incubations. The effects of induction regimen on binding assays conducted under N2 were more equivocal: 3-MC produced a 2-fold increase in binding in both S9 and microsomes, while the other two agents decreased binding from 50 to 75%. These results indicate that classic cytochrome P-450 inducers were able to stimulate activation of NP, but that this activation is not mediated solely by cytochrome P-450.


Assuntos
DNA/metabolismo , Fígado/metabolismo , Pirenos/metabolismo , Aerobiose , Animais , Arocloros/farmacologia , Radioisótopos de Carbono , Bovinos , Sistema Enzimático do Citocromo P-450/metabolismo , Citosol/metabolismo , Masculino , Metilcolantreno/farmacologia , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Fenobarbital/farmacologia , Ratos , Frações Subcelulares/metabolismo , Timo
18.
Environ Health Perspect ; 62: 203-7, 1985 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3841313

RESUMO

Binding of 1-nitro (14C)pyrene (NP) or its metabolites to cellular DNA and protein in cultures of rabbit alveolar macrophages, lung tissue, and tracheal tissue was examined. DNA binding in tracheal tissue (136 +/- 18.3 pmole NP/mg DNA) was four to five times the levels measured in either lung tissue (38 +/- 9.4 pmole NP/mg DNA) or macrophages (26 +/- 7.5 pmole NP/mg DNA). Adduct analysis of DNA isolated from lung tissue incubated with 1-nitro[H3]pyrene in vitro resulted in the identification of 2 to 5% of the NP adducts as C8-deoxyguanosine 1-aminopyrene. NP was also bound to cellular protein in tracheal tissue and lung tissue, and at a lower level in macrophages. Cocultivation of the macrophages with lung and tracheal tissue decreased the DNA binding in tracheal tissue by 45%. Following intratracheal instillation of diesel particles (5 mg) vapor-coated with 14C-NP (380 ppm, 0.085 muCi/mg) particles into rats, 5-8% of the radioactivity remained in the lungs after 20 hr. Most of the diesel particles were also deposited in the lung. Examination of DNA and protein binding in this tissue showed 5 to 12% of the pulmonary 14C bound to protein and no detectable levels of 14C bound to DNA.


Assuntos
DNA/metabolismo , Pulmão/metabolismo , Macrófagos/metabolismo , Pirenos/metabolismo , Traqueia/metabolismo , Animais , Radioisótopos de Carbono , Células Cultivadas , Pulmão/citologia , Macrófagos/citologia , Masculino , Ligação Proteica , Proteínas/metabolismo , Coelhos , Ratos , Ratos Endogâmicos , Traqueia/citologia , Trítio
19.
Environ Health Perspect ; 108(4): 333-9, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10753092

RESUMO

Cigarette smoking is associated with an increased risk of leukemia; benzene, an established leukemogen, is present in cigarette smoke. By combining epidemiologic data on the health effects of smoking with risk assessment techniques for low-dose extrapolation, we assessed the proportion of smoking-induced total leukemia and acute myeloid leukemia (AML) attributable to the benzene in cigarette smoke. We fit both linear and quadratic models to data from two benzene-exposed occupational cohorts to estimate the leukemogenic potency of benzene. Using multiple-decrement life tables, we calculated lifetime risks of total leukemia and AML deaths for never, light, and heavy smokers. We repeated these calculations, removing the effect of benzene in cigarettes based on the estimated potencies. From these life tables we determined smoking-attributable risks and benzene-attributable risks. The ratio of the latter to the former constitutes the proportion of smoking-induced cases attributable to benzene. Based on linear potency models, the benzene in cigarette smoke contributed from 8 to 48% of smoking-induced total leukemia deaths [95% upper confidence limit (UCL), 20-66%], and from 12 to 58% of smoking-induced AML deaths (95% UCL, 19-121%). The inclusion of a quadratic term yielded results that were comparable; however, potency models with only quadratic terms resulted in much lower attributable fractions--all < 1%. Thus, benzene is estimated to be responsible for approximately one-tenth to one-half of smoking-induced total leukemia mortality and up to three-fifths of smoking-related AML mortality. In contrast to theoretical arguments that linear models substantially overestimate low-dose risk, linear extrapolations from empirical data over a dose range of 10- to 100-fold resulted in plausible predictions.


Assuntos
Benzeno/efeitos adversos , Leucemia Mieloide Aguda/etiologia , Leucemia/etiologia , Fumar/efeitos adversos , Adolescente , Adulto , Idoso , Animais , Criança , Pré-Escolar , Estudos de Coortes , Cães , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Leucemia/mortalidade , Leucemia Mieloide Aguda/mortalidade , Tábuas de Vida , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional , Medição de Risco , Poluição por Fumaça de Tabaco/efeitos adversos , Poluição por Fumaça de Tabaco/análise
20.
Bone Marrow Transplant ; 13(6): 811-5, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7920319

RESUMO

DNA amplification using polymerase chain reaction (PCR) primers aiming at eukaryotic or prokaryotic repetitive DNA motifs enables discrimination between individual Candida albicans isolates. This PCR-mediated DNA fingerprinting procedure was used to monitor yeast colonisation in immune-compromised leukaemia patients (n = 11) who were undergoing bone marrow transplantation (BMT). The leukaemia patients remained colonised by the same strain throughout a 5 month study period, irrespective of intermediate treatment with fungostatics or application of BMT-related therapies. All 11 strains could be identified separately by PCR fingerprinting. This implies that spreading of C. albicans from patient to patient does not seem to occur in this study group, despite the fact that medical employees frequently travel between wards which are in close proximity to other departments harbouring neutropenic patients. Several of the patients (n = 35) were also monitored for C. albicans colonisation and strain typing corroborated the lack of extensive cross-contamination during the study period. The application of PCR-mediated genotyping of fungi in epidemiological analyses and evaluation of hospital hygiene is discussed.


Assuntos
Transplante de Medula Óssea , Candida albicans/genética , Sequência de Bases , Medula Óssea/química , Medula Óssea/microbiologia , Células da Medula Óssea , Transplante de Medula Óssea/efeitos adversos , Candida albicans/imunologia , Candida albicans/isolamento & purificação , Candidíase/etiologia , Criança , Pré-Escolar , Impressões Digitais de DNA , DNA Fúngico/análise , DNA Fúngico/genética , Genoma Fúngico , Genótipo , Humanos , Lactente , Dados de Sequência Molecular , Reação em Cadeia da Polimerase
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