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1.
Ann Oncol ; 33(3): 259-275, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34923107

RESUMO

BACKGROUND: Several commercial and academic autologous chimeric antigen receptor T-cell (CAR-T) products targeting CD19 have been approved in Europe for relapsed/refractory B-cell acute lymphoblastic leukemia, high-grade B-cell lymphoma and mantle cell lymphoma. Products for other diseases such as multiple myeloma and follicular lymphoma are likely to be approved by the European Medicines Agency in the near future. DESIGN: The European Society for Blood and Marrow Transplantation (EBMT)-Joint Accreditation Committee of ISCT and EBMT (JACIE) and the European Haematology Association collaborated to draft best practice recommendations based on the current literature to support health care professionals in delivering consistent, high-quality care in this rapidly moving field. RESULTS: Thirty-six CAR-T experts (medical, nursing, pharmacy/laboratory) assembled to draft recommendations to cover all aspects of CAR-T patient care and supply chain management, from patient selection to long-term follow-up, post-authorisation safety surveillance and regulatory issues. CONCLUSIONS: We provide practical, clinically relevant recommendations on the use of these high-cost, logistically complex therapies for haematologists/oncologists, nurses and other stakeholders including pharmacists and health sector administrators involved in the delivery of CAR-T in the clinic.


Assuntos
Hematologia , Receptores de Antígenos Quiméricos , Acreditação , Adulto , Medula Óssea , Humanos , Imunoterapia Adotiva , Receptores de Antígenos de Linfócitos T
2.
Curr Res Transl Med ; 67(3): 79-88, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31182380

RESUMO

PURPOSE OF THE STUDY: Two chimeric antigen receptor (CAR) T-cell therapies - Tisagenlecleucel (Kymriah™) and Axicabtagene ciloleucel (Yescarta™) - have been approved for commercial use. In order to inform forthcoming EBMT guidelines on the management of adults and children undergoing autologous CAR T-cell therapy, we undertook a survey of experienced clinicians. METHODS: An online survey with a dual focus on (1) 'real world' patient eligibility criteria and (2) models of care for patient follow-up was sent to experienced physicians. RESULTS: There were 41 respondents (10 countries) and 93% worked in FACT-JACIE-accredited transplant centres. Most felt that a history of malignancy (57%), prior allo-HCT for B-NHL (78%-81%) and prior treatment with anti-CD19/CD3 BiTE antibodies (76%-86%) do not constitute contra-indications to CAR T therapy. Clinicians were divided as to whether CNS involvement represented an exclusion criterion. There was agreement that patients with viral infections (HIV, Hepatitis B or Hepatitis C) are not eligible. There is no common model of care for long-term follow-up. Most respondents believed that patients should attend the hospital two (43%) to three (33%) times weekly during the first month following discharge. A majority (69%) of respondents work in centres where there is an MDT meeting with a specific focus on follow-up following CAR T Therapy. Follow-up care is currently delivered either in HCT or haematology-oncology outpatient clinics. CONCLUSION: The responses reveal wide variation in perceived patient eligibility criteria and highlight the need for consensus guidelines. The findings also illustrate the embryonic nature of current follow-up arrangements.


Assuntos
Neoplasias Hematológicas/epidemiologia , Neoplasias Hematológicas/terapia , Imunoterapia Adotiva/métodos , Receptores de Antígenos Quiméricos/genética , Linfócitos T/transplante , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD19/uso terapêutico , Produtos Biológicos , Criança , Pré-Escolar , Doença Crônica , Europa (Continente)/epidemiologia , Seguimentos , Neoplasias Hematológicas/imunologia , Humanos , Imunoterapia Adotiva/normas , Imunoterapia Adotiva/estatística & dados numéricos , Lactente , Internacionalidade , Pessoa de Meia-Idade , Neoplasias/epidemiologia , Neoplasias/terapia , Seleção de Pacientes , Receptores de Antígenos de Linfócitos T/uso terapêutico , Receptores de Antígenos Quiméricos/imunologia , Receptores de Antígenos Quiméricos/metabolismo , Sociedades Médicas , Inquéritos e Questionários , Linfócitos T/metabolismo , Adulto Jovem
3.
J Thromb Haemost ; 14(6): 1200-5, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26991062

RESUMO

UNLABELLED: Essentials Treatment options are limited for refractory bleeding in acquired von Willebrand Syndrome (AVWS). Lenalidomide therapy was studied in two patients with AVWS due to monoclonal gammopathy (MG). Lenalidomide increased von Willebrand factor (VWF), lowered VWF clearance and resolved bleeding. Lenalidomide is a potential treatment option for refractory bleeding in AVWS secondary to MG. SUMMARY: Background Acquired von Willebrand syndrome (AVWS) is associated with lymphoproliferative disorders, including monoclonal gammopathy (MG) of undetermined significance (MGUS) and multiple myeloma. Patients commonly present with significant bleeding complications that are difficult to manage, owing to a markedly reduced von Willebrand factor (VWF) half-life. Objectives To investigate the use of the immunomodulatory drug lenalidomide in two patients with severe refractory bleeding caused by AVWS associated with MGs. Results In both patients, lenalidomide treatment resulted in significant clinical improvement, and marked increases in plasma VWF antigen (VWF:Ag) and VWF ristocetin cofactor levels. This normalization in plasma VWF levels was sustained for > 2 years in both patients. Furthermore, in one patient, plasma VWF levels remain normal for at least 14 months following discontinuation of lenalidomide treatment. To investigate the molecular mechanisms underlying these observations, VWF propeptide (VWFpp)/VWF:Ag ratios were analyzed to assess VWF clearance. At enrolment, plasma VWFpp/VWF:Ag ratios were significantly elevated in both patients. Importantly, lenalidomide treatment resulted in normalization of VWFpp/VWF:Ag ratios in both patients. These novel data suggest that lenalidomide functions to attenuate enhanced VWF clearance in AVWS. Interestingly, in a patient with MGUS, lenalidomide treatment was associated with a significant increase in plasma VWF levels, despite no major change in paraprotein level. Conclusions Collectively, our findings suggest that lenalidomide constitutes a novel therapeutic option for the management of AVWS associated with MG. The biological mechanism(s) through which lenalidomide causes a sustained increase in plasma VWF levels in AVWS independently of paraprotein level requires further study, but is in part modulated through inhibition of enhanced VWF clearance.


Assuntos
Paraproteinemias/tratamento farmacológico , Talidomida/análogos & derivados , Doenças de von Willebrand/tratamento farmacológico , Idoso , Anticoagulantes/uso terapêutico , Esquema de Medicação , Hemorragia , Humanos , Lenalidomida , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/imunologia , Paraproteinemias/sangue , Paraproteinemias/complicações , Indução de Remissão , Talidomida/uso terapêutico , Resultado do Tratamento , Doenças de von Willebrand/sangue , Doenças de von Willebrand/complicações , Fator de von Willebrand/uso terapêutico
4.
Ir J Med Sci ; 174(2): 26-32, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16094909

RESUMO

BACKGROUND: High-dose treatment with autologous stem cell transplantation (ASCT) has become the standard of care for patients with myeloma below the age of 65 years. AIMS: We report an audit of 60 patients (median age: 52.5 years) who underwent ASCT in the National Bone Marrow Transplant centre in St James's Hospital in Dublin between 1997 and 2003 inclusive. METHODS: Clinical and laboratory data were retrieved from patient medical records and hospital information management systems. RESULTS: Thirty-six patients had IgG, 11 IgA, 1 IgD, 9 light chain and 3 non-secretory MM. Fifty-seven (95%) patients received anthracycline-corticosteroid combination chemotherapy prior to autografting. There was no transplant-related mortality (TRM). Complete (CR) and Partial Responses (PR) were seen in 16 (29.6%) and 29 (53.7%) of those evaluable (n = 54 (90%)). The actuarial Progression-Free (PFS) and Overall Survival (OS) rates at five years are 13% and 55% respectively. CONCLUSION: Centre outcome is comparable to published international series and supports the use of ASCT in the treatment of this malignancy.


Assuntos
Mieloma Múltiplo/cirurgia , Transplante de Células-Tronco de Sangue Periférico , Transplante Autólogo , Resultado do Tratamento , Idoso , Progressão da Doença , Feminino , Humanos , Irlanda , Masculino , Auditoria Médica , Pessoa de Meia-Idade , Mieloma Múltiplo/mortalidade , Mieloma Múltiplo/fisiopatologia , Estudos Retrospectivos , Análise de Sobrevida
5.
Bone Marrow Transplant ; 34(6): 545-56, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15343272

RESUMO

A total of 75 patients underwent sibling allogeneic stem cell transplantation (SCT) for chronic myeloid leukaemia in first chronic phase from 1984 to 2000. Of these patients, 51 (68%) were alive at a median follow-up of 98 months (range 34-217 months). Nine (18%) patients relapsed and seven (14%) received donor lymphocyte transfusions. Quality of life (QoL) was assessed cross-sectionally using the EORTC QLQ-C30, a Leukaemia-BMT-specific module and questionnaires on sexual functioning, fertility and late effects. A total of 46 (90%) replied. Scores for Role (P=0.018) and Cognitive (P<0.001) function were significantly lower when compared to an age-adjusted general population. Dyspnoea (P=0.022) and Financial Difficulties (P<0.001) were significantly more common in the SCT group. No difference was found for scores in the Physical, Emotional and Social domains or the overall Global Health Status/QoL. Decreased sexual functioning was found in one-third of respondents. Although most BMT recipients reported a good QoL, a minority have difficulty with reintegration into professional roles and consequent monetary problems. Identified cognitive and sexual impairments highlight the need for long-term access to psychosocial support.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva/psicologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Qualidade de Vida , Transplante de Células-Tronco/psicologia , Sistema ABO de Grupos Sanguíneos , Adolescente , Adulto , Incompatibilidade de Grupos Sanguíneos , Transplante de Medula Óssea/psicologia , Transtornos Cognitivos/epidemiologia , Feminino , Seguimentos , Humanos , Depleção Linfocítica , Masculino , Pessoa de Meia-Idade , Psicoterapia , Estudos Retrospectivos , Comportamento Sexual , Irmãos , Inquéritos e Questionários , Fatores de Tempo , Transplante Homólogo
6.
Int J Lab Hematol ; 34(4): 417-21, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22313586

RESUMO

Hairy cell leukaemia (HCL) has distinct clinical, morphological and immunophenotypic features with no recurrent cytogenetic or molecular abnormalities reported until the recent description of the BRAF V600E mutation in patients with classical HCL. The incidence of this mutation was sought in 27 patients with either classical HCL or HCL variant by an allele-specific PCR approach and findings related to morphology, cytochemistry and immunophenotype. A high degree of correlation was noted between the presence of BRAF V600E and established diagnostic criteria in 26/27 patients with HCL/HCL variant. Detection of the BRAF V600E mutation is therefore a useful adjunct in the differential diagnosis of HCL and HCL variant and highlights the value of a multifaceted approach to the diagnosis of this malignancy.


Assuntos
Leucemia de Células Pilosas/diagnóstico , Leucemia de Células Pilosas/genética , Mutação , Proteínas Proto-Oncogênicas B-raf/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Células da Medula Óssea/patologia , Diagnóstico Diferencial , Feminino , Variação Genética , Histocitoquímica , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
7.
Bone Marrow Transplant ; 47(1): 18-23, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21358693

RESUMO

We describe 20 patients with myeloma and 1 with primary amyloidosis from 15 centres, all with advanced renal failure, most of whom had PBSC mobilised using plerixafor following previous failed mobilisation by conventional means (plerixafor used up-front for 4 patients). For 15 patients, the plerixafor dose was reduced to 0.16 mg/kg/day, with a subsequent dose increase in one case to 0.24 mg/kg/day. The remaining six patients received a standard plerixafor dosage at 0.24 mg/kg/day. Scheduling of plerixafor and apheresis around dialysis was generally straightforward. Following plerixafor administration, all patients underwent apheresis. A median CD34+ cell dose of 4.6 × 10(6) per kg was achieved after 1 (n=7), 2 (n=10), 3 (n=3) or 4 (n=1) aphereses. Only one patient failed to achieve a sufficient cell dose for transplant: she subsequently underwent delayed re-mobilisation using G-CSF with plerixafor 0.24 mg/kg/day, resulting in a CD34+ cell dose of 2.12 × 10(6)/kg. Sixteen patients experienced no plerixafor toxicities; five had mild-to-moderate gastrointestinal symptoms that did not prevent apheresis. Fifteen patients have progressed to autologous transplant, of whom 12 remain alive without disease progression. Two patients recovered endogenous renal function post autograft, and a third underwent successful renal transplantation. Plerixafor is highly effective in mobilising PBSC in this difficult patient group.


Assuntos
Fármacos Anti-HIV/administração & dosagem , Mobilização de Células-Tronco Hematopoéticas/métodos , Compostos Heterocíclicos/administração & dosagem , Mieloma Múltiplo/terapia , Transplante de Células-Tronco de Sangue Periférico , Insuficiência Renal/terapia , Adulto , Idoso , Fármacos Anti-HIV/efeitos adversos , Benzilaminas , Remoção de Componentes Sanguíneos , Ciclamos , Relação Dose-Resposta a Droga , Feminino , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Fator Estimulador de Colônias de Granulócitos/efeitos adversos , Mobilização de Células-Tronco Hematopoéticas/efeitos adversos , Compostos Heterocíclicos/efeitos adversos , Humanos , Transplante de Rim , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/complicações , Diálise Renal , Insuficiência Renal/complicações , Transplante Autólogo , Transplante Homólogo
11.
Toxicol In Vitro ; 24(5): 1450-63, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20350595

RESUMO

There is an urgent need to validate in vitro human skin models for use in safety testing. An important component of validation is characterizing the metabolizing capacity of these models. We report comparison of the expression of 139 genes encoding xenobiotic metabolizing enzymes in the EpiDerm model and human skin. In microarray analysis, the expression of 87% of the genes was consistent between the EpiDerm model and human skin indicating the presence of similar metabolic pathways suggesting commonality in function. Analysis of EpiDerm models constructed from four donors showed highly comparable expression of xenobiotic metabolizing genes demonstrating reproducibility of the model. Overall, the expression of Phase II enzymes appeared to be more pronounced in human skin and the EpiDerm model than that of Phase I enzymes, consistent with the role of skin in detoxification of xenobiotics. Though the basal expression of CYPs in particular was low in EpiDerm, significant induction of CYP1A1/1B1 activity was observed following treatment with 3-methylcholanthrene. These results indicate that the xenobiotic metabolizing capacity of the EpiDerm model appears to be representative of human skin. Models such as EpiDerm provide a valuable in vitro approach for evaluation of metabolism and toxicity of cutaneous exposures to xenobiotics.


Assuntos
Epiderme/metabolismo , Expressão Gênica/efeitos dos fármacos , Modelos Biológicos , Pele/metabolismo , Xenobióticos/metabolismo , Adolescente , Biotransformação , Citocromo P-450 CYP1A1/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Indução Enzimática/efeitos dos fármacos , Epiderme/efeitos dos fármacos , Epiderme/enzimologia , Feminino , Glucuronosiltransferase/metabolismo , Glutationa Transferase/metabolismo , Humanos , Técnicas In Vitro , Inativação Metabólica , Análise de Sequência com Séries de Oligonucleotídeos , Pele/efeitos dos fármacos , Pele/enzimologia , Xenobióticos/toxicidade , Adulto Jovem
13.
Eur J Haematol ; 76(3): 258-60, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16451399

RESUMO

Secondary or late graft failure has been defined as the development of inadequate marrow function after initial engraftment has been achieved. We describe a case of profound marrow aplasia occurring 13 years after sibling allogeneic bone marrow transplantation for chronic myeloid leukaemia (CML) in first chronic phase. Although the patient remained a complete donor chimera, thereby suggesting that an unselected infusion of donor peripheral blood stem cells (PBSC) or bone marrow might be indicated, the newly acquired aplasia was thought to be immune in aetiology and some immunosuppression was therefore considered appropriate. Rapid haematological recovery was achieved after the infusion of unselected PBSC from the original donor following conditioning with anti-thymocyte globulin (ATG).


Assuntos
Doenças da Medula Óssea/etiologia , Transplante de Medula Óssea/efeitos adversos , Leucemia Mielogênica Crônica BCR-ABL Positiva/complicações , Soro Antilinfocitário/uso terapêutico , Doenças da Medula Óssea/tratamento farmacológico , Doenças da Medula Óssea/patologia , Transplante de Medula Óssea/métodos , Feminino , Teste de Histocompatibilidade , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Pessoa de Meia-Idade , Transplante de Células-Tronco de Sangue Periférico , Irmãos , Transplante Homólogo , Resultado do Tratamento
14.
Chem Res Toxicol ; 6(2): 231-7, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8386561

RESUMO

Certain 1,8-dihydroxy-9-anthrones have been used for the topical treatment of psoriasis for over seventy-five years. The therapeutic usefulness of these compounds is limited, however, by side effects including severe skin inflammation and staining. Antipsoriatic 9-anthrones are also tumor promoters in mouse skin. The chemical mechanisms underlying the biological properties of 9-anthrones are believed to involve the generation of free radical products such as 9-anthron-10-yl radicals or secondary oxygen radicals such as O2.- or OH.. However, the specific role that 9-anthron-10-yl radicals may play in mediating the biological effects of 9-anthrones is uncertain because these species have not been detected in biological systems. In the present study we have used the EPR spin trapping technique to demonstrate for the first time the formation of the 1,8-dihydroxy-9-anthron-10-yl radical in aqueous buffers. Additionally, in order to gain information concerning the role of 9-anthron-10-yl radicals in tumor promotion and antipsoriatic activities, we have used this technique to investigate the formation of these radical species by a series of 9-anthrones of known tumor-promoting and antipsoriatic activities. All of the 9-anthrones studied formed spin adducts with 3,5-dibromo-4-nitrosobenzenesulfonic acid in aqueous buffers. The formation of these adducts was pH-dependent, being favored at alkaline pH.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Antracenos/análise , Antracenos/química , Carcinógenos/química , Psoríase/tratamento farmacológico , Antralina/análise , Soluções Tampão , Espectroscopia de Ressonância de Spin Eletrônica , Radicais Livres , Concentração de Íons de Hidrogênio , Oxirredução , Espectrofotometria Ultravioleta , Temperatura
15.
Mol Pharmacol ; 37(3): 468-76, 1990 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2314393

RESUMO

The 14C-labeled, 35S-labeled, and unlabeled nephrotoxic cysteine conjugates S-(1,2-dichlorovinyl)-L-cysteine, S-(2-chloro-1,1,2-trifluoroethyl)- L-cysteine, S-(1,1,2,2-tetrafluoroethyl)-L-cysteine, S-(1,2,3,4,4-pentachlorobutadienyl)-L- cysteine (PCBC), and S-(1,1,2,3,3,3-hexafluoropropyl)-L-cysteine were synthesized and their toxicities were compared in isolated rat renal mitochondria. Inhibition of respiration, covalent binding to macromolecules, metabolism by mitochondria, metabolism by a purified cysteine conjugate beta-lyase (beta-lyase), and octanol/water partition coefficients were studied. All of the conjugates inhibited mitochondrial state 3 respiration. Only PCBC was found to uncouple oxidative phosphorylation. (Aminooxy)acetic acid, a beta-lyase inhibitor, blocked the effects of the conjugates on state 3 respiration except for the uncoupling effect of PCBC, which was not blocked. Binding of 35S label to macromolecules was observed after treatment with each of the 35S-labeled conjugates, and (aminooxy)acetic acid blocked the binding. The relative amounts of metabolism of the conjugates did not correlate well with their relative binding and toxicities, indicating some differential reactivity of metabolites and/or selectivity for binding targets. Some of the binding from 35S-labeled conjugates was removed by treatment with the disulfide-reducing agent dithiothreitol, suggesting that some of the binding was via mixed disulfides. The amount of dithiothreitol-sensitive binding differed among the conjugates. The metabolism of PCBC by permeabilized mitochondria, but not by a purified beta-lyase, was consistent with its relative toxicity and covalent binding, suggesting the involvement of other beta-lyase enzymes in the activation of PCBC to toxic species in mitochondria.


Assuntos
Liases de Carbono-Enxofre , Cisteína/metabolismo , Córtex Renal/metabolismo , Difosfato de Adenosina/metabolismo , Técnicas In Vitro , Córtex Renal/efeitos dos fármacos , Liases/metabolismo , Substâncias Macromoleculares , Espectroscopia de Ressonância Magnética , Mitocôndrias/metabolismo , Oxirredução , Consumo de Oxigênio/efeitos dos fármacos , Solubilidade , Transaminases/metabolismo
16.
Mol Pharmacol ; 46(1): 186-98, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8058052

RESUMO

The biological properties of tumor-promoting and antipsoriatic 9-anthrones have been hypothesized to be mediated by free radical products such as the corresponding 9-anthron-10-yl radicals or by O2-, OH, and other persistent secondary radicals that are formed in the skin after topical treatment with 9-anthrones. To gain additional insights into the possible role of reactive oxygen or secondary radicals in mediating the biological effects of 9-anthrones, we have used EPR spectroscopy to investigate the formation of these species by a series of 9-anthrones or 9-anthrone dimers with known tumor-promoting and antipsoriatic activities. The effect of the 9-anthrones on keratinocyte proliferation in vitro was also investigated. 5,5-Dimethyl-1-pyrroline N-oxide was used as a spin trap to detect reactive oxygen-centered radicals in aqueous buffer/dimethylsulfoxide solutions. Super-radicals in aqueous buffer/dimethylsulfoxide solutions. Superoxide was trapped during the autoxidation of most of the 9-anthrones. For 9-anthrones that generated no detectable superoxide, evidence of anthronyl-peroxyl radical formation was found instead. In the presence of Fe3+ complexed to EDTA, but not diethylenetriaminepentaacetic acid, the hydroxyl radical was produced by all of the 9-anthrones. 9-Anthrone dimers produced oxygen-centered radicals only weakly or not at all. Direct EPR was used to detect 9-anthrone-derived secondary radicals in keratinocyte suspensions or in dimethysulfoxide solutions. These radicals were similar to those previously reported to occur in skin after topical treatment with the antipsoriatic drug anthralin (1,8-dihydroxy-9-anthrone). In contrast to the ubiquitous ability of the 9-anthrones to generate reactive oxygen radicals, only the hydroxy-substituted 9-anthrones or their dimers possessed significant secondary radical-forming ability. The ability of the 9-anthrones or dimers to form secondary radicals in keratinocytes was found to correlate with their in vitro inhibition of keratinocyte proliferation. The data suggest the possible importance of reactive dimeric intermediates in mediating the biological effects of the 9-anthrones.


Assuntos
Antracenos/farmacologia , Queratinócitos/efeitos dos fármacos , Animais , Antracenos/química , Antracenos/metabolismo , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Óxidos N-Cíclicos , Espectroscopia de Ressonância de Spin Eletrônica , Radicais Livres , Queratinócitos/citologia , Camundongos , Camundongos Endogâmicos BALB C , Ácido Pentético , Marcadores de Spin , Relação Estrutura-Atividade
17.
Drug Metab Dispos ; 17(3): 297-303, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2568912

RESUMO

In this study, we have established the selectivity of inhibitors for rat kidney cysteine conjugate beta-lyase and L-alpha-hydroxy acid oxidase (L-amino acid oxidase) and have used these inhibitors to explore the relative roles of these two enzymes in the metabolism of nephrotoxic cysteine conjugates by rat kidney homogenate. In addition, we have investigated the relationship between structure and the metabolism of toxic cysteine conjugates by purified rat kidney L-alpha-hydroxy acid oxidase. With purified enzyme, S-(1,2,3,4,4-pentachlorobutadienyl)-L-cysteine (PCBDC) was about four times more active than S(1,2-dichlorovinyl)-L-cysteine (DCVC). Three alkyl conjugates were less active than DCVC. Purified L-alpha-hydroxy acid oxidase was not inhibited by the beta-lyase inhibitor aminooxyacetic acid but was inactivated by 2-hydroxy-3-butynoate. PCBDC metabolism in rat kidney homogenate was inhibited 74% by aminooxyacetic acid and 42% by 2-hydroxy-3-butynoate, whereas DCVC metabolism was inhibited 77% by aminooxyacetic acid and 28% by 2-hydroxy-3-butynoate. However, only aminooxyacetic acid inhibited the binding of 35S label from [35S]DCVC. Based on these results we have reached three conclusions. First, L-alpha-hydroxy acid oxidase plays a significant role in the metabolism of some cysteine conjugates. Second, metabolism of DCVC by L-alpha-hydroxy acid oxidase does not contribute directly to covalent binding. Third, as much as 65% of DCVC may be metabolized to its corresponding alpha-keto acid. The results are discussed with regard to the nephrotoxicity of cysteine conjugates.


Assuntos
Aminoácido Oxirredutases/antagonistas & inibidores , Liases de Carbono-Enxofre , Cisteína/metabolismo , Nefropatias/induzido quimicamente , Liases/antagonistas & inibidores , Aminoácido Oxirredutases/metabolismo , Ácido Amino-Oxiacético/metabolismo , Animais , Cisteína/análogos & derivados , Cisteína/farmacologia , Cisteína/toxicidade , Concentração de Íons de Hidrogênio , Hidroxibutiratos/metabolismo , Técnicas In Vitro , Rim/efeitos dos fármacos , Rim/metabolismo , L-Aminoácido Oxidase , Fígado/enzimologia , Liases/metabolismo , Masculino , Ratos , Radioisótopos de Enxofre , Fatores de Tempo
18.
J Biochem Toxicol ; 8(1): 49-56, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8492303

RESUMO

The relationship between the covalent binding, uptake, and toxicity produced by S-(1,2-dichlorovinyl)-L-cysteine (DCVC) and S-(1,1,2,2-tetrafluoroethyl)-L-cysteine (TFEC) was investigated in suspensions of rabbit renal proximal tubules (RPT). The DCVC and TFEC at concentrations of 25 microM produced a time-dependent (1-6 hours) loss of RPT viability. The TFEC was biotransformed rapidly by beta-lyase to a reactive metabolite which bound covalently to tubular protein. Approximately 63% of the TFEC-equivalents inside the cell were bound to protein. Covalent binding of TFEC-equivalents was associated with a 30% decrease in tubular basal and state 3 respiration, a sevenfold increase in lipid peroxidation, and, ultimately, cell death. The DCVC was biotransformed rapidly to a reactive metabolite which bound covalently to tubular protein. Approximately 90% of the DCVC-equivalents inside the cell were bound covalently to tubular protein. Following exposure to 25 microM DCVC, the binding of DCVC-equivalents was associated with a 17-fold increase in lipid peroxidation but, in contrast to TFEC, had no effect on tubular respiration. However, exposure of RPT to 100 microM DCVC resulted in a ninefold increase in the binding of DCVC-equivalents and a 30% decrease in tubular state 3 respiration. The beta-lyase inhibitor aminooxyacetic acid (AOAA) blocked the covalent binding, mitochondrial dysfunction, lipid peroxidation, and cell death produced by TFEC. The AOAA decreased the covalent binding and the lipid peroxidation produced by DCVC by approximately 60-70% but had no effect on cell death.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Cisteína/toxicidade , Hidrocarbonetos Halogenados/toxicidade , Túbulos Renais Proximais/efeitos dos fármacos , Ácido Amino-Oxiacético/farmacologia , Animais , Biotransformação , Morte Celular/efeitos dos fármacos , Cisteína/análogos & derivados , Cisteína/farmacocinética , Feminino , Hidrocarbonetos Fluorados/farmacocinética , Hidrocarbonetos Fluorados/toxicidade , Hidrocarbonetos Halogenados/farmacocinética , Técnicas In Vitro , Túbulos Renais Proximais/citologia , Peroxidação de Lipídeos/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Coelhos , Radioisótopos de Enxofre
19.
Chem Res Toxicol ; 7(6): 877-81, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7696546

RESUMO

Certain 9-anthrone derivatives are useful in treating psoriasis and are also known to be tumor promoters in mouse skin. Their therapeutic use is accompanied by side effects of severe skin inflammation, irritation, and staining. The precise biochemical mechanisms of therapeutic action, tumor promotion, and side effects are presently uncertain, although the corresponding 9-anthron-10-yl radicals have been proposed as important intermediates. In order to gain insight into the possible role of anthrone-derived radicals in mediating the biological effects of these compounds, in the present study free radicals from a number of anthrone derivatives were generated by thermolysis in nonpolar solvents. Hyperfine splitting constants (hfsc) of the radicals were determined by electron paramagnetic resonance (EPR) spectroscopy. The experimentally determined hfsc's were also compared with spin densities obtained by molecular calculations (MOPAC 6.0). The experimental and theoretical data were found to be consistent in all cases. The formation of 9-anthron-10-yl radicals appears to be a general phenomenon among 9-anthrones regardless of therapeutic or tumor-promoting effectiveness, although there is a trend toward easier radical formation for the more active compounds.


Assuntos
Antracenos/química , Carcinógenos/química , Administração Tópica , Anti-Inflamatórios/química , Espectroscopia de Ressonância de Spin Eletrônica , Radicais Livres/química , Psoríase/tratamento farmacológico , Solventes , Relação Estrutura-Atividade
20.
J Biol Chem ; 266(28): 18415-8, 1991 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-1917965

RESUMO

Antibodies raised against halothane metabolite adducts cross-react with S-(1,1,2,2-tetrafluoroethyl)-L-cysteine (TFEC) and S-(2-chloro-1,1,2-trifluoroethyl)-L-cysteine metabolite adducts. Using these antibodies in immunohistochemical experiments, metabolite binding was localized to the damaged areas of the proximal tubule after treatment of male rats with TFEC. Immunoblot analysis of subcellular fractions of rat kidney tissue after in vivo treatment with TFEC revealed a high specificity for binding of metabolites to proteins of the mitochondrial fraction. These proteins may represent target molecules which play a role in cysteine conjugate induced nephrotoxicity.


Assuntos
Cisteína/análogos & derivados , Fluoracetatos , Halotano/imunologia , Hidrocarbonetos Fluorados/análise , Mitocôndrias/metabolismo , Acetamidas , Animais , Reações Cruzadas , Cisteína/análise , Cisteína/imunologia , Ensaio de Imunoadsorção Enzimática , Hidrocarbonetos Fluorados/imunologia , Immunoblotting , Imuno-Histoquímica , Nefropatias/induzido quimicamente , Nefropatias/metabolismo , Túbulos Renais Proximais/metabolismo , Cinética , Masculino , Ratos , Ratos Endogâmicos , Ácido Trifluoracético/imunologia
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