Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Nature ; 467(7313): 318-22, 2010 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-20844535

RESUMO

The ß-haemoglobinopathies are the most prevalent inherited disorders worldwide. Gene therapy of ß-thalassaemia is particularly challenging given the requirement for massive haemoglobin production in a lineage-specific manner and the lack of selective advantage for corrected haematopoietic stem cells. Compound ß(E)/ß(0)-thalassaemia is the most common form of severe thalassaemia in southeast Asian countries and their diasporas. The ß(E)-globin allele bears a point mutation that causes alternative splicing. The abnormally spliced form is non-coding, whereas the correctly spliced messenger RNA expresses a mutated ß(E)-globin with partial instability. When this is compounded with a non-functional ß(0) allele, a profound decrease in ß-globin synthesis results, and approximately half of ß(E)/ß(0)-thalassaemia patients are transfusion-dependent. The only available curative therapy is allogeneic haematopoietic stem cell transplantation, although most patients do not have a human-leukocyte-antigen-matched, geno-identical donor, and those who do still risk rejection or graft-versus-host disease. Here we show that, 33 months after lentiviral ß-globin gene transfer, an adult patient with severe ß(E)/ß(0)-thalassaemia dependent on monthly transfusions since early childhood has become transfusion independent for the past 21 months. Blood haemoglobin is maintained between 9 and 10 g dl(-1), of which one-third contains vector-encoded ß-globin. Most of the therapeutic benefit results from a dominant, myeloid-biased cell clone, in which the integrated vector causes transcriptional activation of HMGA2 in erythroid cells with further increased expression of a truncated HMGA2 mRNA insensitive to degradation by let-7 microRNAs. The clonal dominance that accompanies therapeutic efficacy may be coincidental and stochastic or result from a hitherto benign cell expansion caused by dysregulation of the HMGA2 gene in stem/progenitor cells.


Assuntos
Transfusão de Sangue , Terapia Genética , Proteína HMGA2/metabolismo , Globinas beta/genética , Globinas beta/metabolismo , Talassemia beta/genética , Talassemia beta/terapia , Adolescente , Células Sanguíneas/citologia , Células Sanguíneas/metabolismo , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Pré-Escolar , Células Clonais/metabolismo , Expressão Gênica , Vetores Genéticos/genética , Proteína HMGA2/genética , Homeostase , Humanos , Lentivirus/genética , Masculino , MicroRNAs/genética , Especificidade de Órgãos , RNA Mensageiro/análise , RNA Mensageiro/genética , Fatores de Tempo , Ativação Transcricional , Adulto Jovem , Talassemia beta/metabolismo
2.
J Infect Dis ; 208(6): 892-7, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23801606

RESUMO

Stored plasma specimens from 164 participants in the ANRS 138 trial were analyzed to determine interleukin 6 (IL-6), high-sensitivity C-reactive protein (hsCRP), and D-dimer levels at baseline and weeks 24 and 48. These virologically suppressed, treatment-experienced patients were randomly assigned to undergo an immediate switch (IS) or a deferred switch (DS; at week 24) from an enfuvirtide-based antiretroviral therapy (ART) regimen to a raltegravir-based regimen. At week 24, a significant decrease from baseline was observed in the IS arm, compared with the DS arm, for IL-6 level (-30% vs +10%; P < .002), hsCRP level (-46% vs +15%; P < .0001), and D-dimer level (-40% vs +6%; P < .0001). At week 48, there was a reproducible decrease in levels of all biomarkers in the DS arm.


Assuntos
Biomarcadores/sangue , Coagulação Sanguínea/efeitos dos fármacos , Proteína gp41 do Envelope de HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Inflamação/sangue , Fragmentos de Peptídeos/uso terapêutico , Pirrolidinonas/uso terapêutico , Adulto , Fármacos Anti-HIV/uso terapêutico , Proteína C-Reativa/análise , Contagem de Linfócito CD4 , Enfuvirtida , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Infecções por HIV/sangue , Infecções por HIV/virologia , HIV-1 , Humanos , Inflamação/virologia , Interleucina-6/sangue , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue , Raltegravir Potássico , Manejo de Espécimes , Carga Viral
3.
J Health Popul Nutr ; 31(1): 28-36, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23617202

RESUMO

Vitamin A status in a sample of pregnant and lactating women living in several representative regions of Congo was assessed and compared between August and September 2004. This survey was conducted using a randomized two-stage cluster-sampling method with stratification on 90 clusters, each consisting of at least 15 women. Vitamin A status was determined in a total of 1,054 individuals, using the impression cytology with transfer (ICT) test, the modified relative dose response test (MRDR test) on dried blood spots (DBS), and clinical examination to detect signs of xerophthalmia. The clinical criterion defining vitamin A deficiency was the presence of active xerophthalmia (Bitot's spots [X1B]), active corneal disease), and/or night blindness (XN stage). The prevalence of clinical signs of stage XN and X1B xerophthalmia in the Republic of Congo was found to be 16% and 19% respectively. The prevalence of clinical signs (X1B) was greater in the rural north than in urban areas, with a gradient running from urban (5%) to rural area (33%); 27% of all the ICT tests showed that the subjects were suffering from vitamin A deficiency. The deficiency rates were significantly higher (p < 0.001) in urban surroundings (Brazzaville) than in the rural northern regions. The biochemical MRDR test showed the presence of vitamin A deficiency (> or = 0.06) in 26% of the mothers in Brazzaville compared to 6% in the town of Kouilou; 44% of the women had retinol levels of < 10 microg/dL in the rural north whereas these percentages were significantly lower in the urban areas surveyed (chi-square = 62.30, p < 0.001). A significant correlation was found to exist (p < 0.001) between the ICT test and the MRDR test on DBS. In the population as a whole, 30% of the mothers suffering from malarial attack had abnormally low MRDR levels (> or = 0.06) compared to no malaria. The results of the present study confirm that vitamin A deficiency is a serious public-health issue in pregnant and lactating mothers in the Republic of Congo.


Assuntos
Deficiência de Vitamina A/epidemiologia , Congo/epidemiologia , Feminino , Humanos , Lactação , Vigilância da População/métodos , Gravidez , Prevalência , População Rural/estatística & dados numéricos , População Urbana/estatística & dados numéricos
4.
Antimicrob Agents Chemother ; 55(10): 4905-7, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21788466

RESUMO

To prevent acquisition of HIV through oral sex, drugs used for preexposure prophylaxis (Prep) need to diffuse in saliva. We measured tenofovir (TFV) and emtricitabine (FTC) concentrations simultaneously in the plasma and saliva of 41 HIV-infected patients under stable antiretroviral treatment. Mean ratios of saliva/plasma concentration were 3% (±4%) and 86.9% (±124%) for TFV and FTC, respectively. Tenofovir disoproxil fumarate (TDF) should be used in combination with FTC to prevent oral acquisition of HIV.


Assuntos
Adenina/análogos & derivados , Fármacos Anti-HIV/análise , Desoxicitidina/análogos & derivados , Infecções por HIV/prevenção & controle , Organofosfonatos/análise , Saliva/química , Adenina/administração & dosagem , Adenina/análise , Adenina/sangue , Adenina/uso terapêutico , Adulto , Fármacos Anti-HIV/administração & dosagem , Fármacos Anti-HIV/sangue , Fármacos Anti-HIV/uso terapêutico , Desoxicitidina/administração & dosagem , Desoxicitidina/análise , Desoxicitidina/sangue , Desoxicitidina/uso terapêutico , Quimioterapia Combinada , Emtricitabina , Infecções por HIV/tratamento farmacológico , Infecções por HIV/transmissão , HIV-1/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Organofosfonatos/administração & dosagem , Organofosfonatos/sangue , Organofosfonatos/uso terapêutico , Comportamento Sexual , Tenofovir
5.
J Exp Med ; 196(10): 1373-80, 2002 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-12438428

RESUMO

Differentiation therapy for acute myeloid leukemia uses transcriptional modulators to reprogram cancer cells. The most relevant clinical example is acute promyelocytic leukemia (APL), which responds dramatically to either retinoic acid (RA) or arsenic trioxide (As(2)O(3)). In many myeloid leukemia cell lines, cyclic adenosine monophosphate (cAMP) triggers growth arrest, cell death, or differentiation, often in synergy with RA. Nevertheless, the toxicity of cAMP derivatives and lack of suitable models has hampered trials designed to assess the in vivo relevance of theses observations. We show that, in an APL cell line, cAMP analogs blocked cell growth and unraveled As(2)O(3)-triggered differentiation. Similarly, in RA-sensitive or RA-resistant mouse models of APL, continuous infusions of 8-chloro-cyclic adenosine monophosphate (8-Cl-cAMP) triggered major growth arrest, greatly enhanced both spontaneous and RA- or As(2)O(3)-induced differentiation and accelerated the restoration of normal hematopoiesis. Theophylline, a well-tolerated phosphodiesterase inhibitor which stabilizes endogenous cAMP, also impaired APL growth and enhanced spontaneous or As(2)O(3)-triggered cell differentiation in vivo. Accordingly, in an APL patient resistant to combined RA-As(2)O(3) therapy, theophylline induced blast clearance and restored normal hematopoiesis. Taken together, these results demonstrate that in vivo activation of cAMP signaling contributes to APL clearance, independently of its RA-sensitivity, thus raising hopes that other myeloid leukemias may benefit from this therapeutic approach.


Assuntos
Diferenciação Celular , Divisão Celular , AMP Cíclico/metabolismo , Leucemia Promielocítica Aguda/metabolismo , Transdução de Sinais , Animais , Trióxido de Arsênio , Arsenicais/farmacologia , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Leucemia Promielocítica Aguda/patologia , Camundongos , Camundongos Transgênicos , Óxidos/farmacologia , Teofilina/farmacologia , Tretinoína/farmacologia , Células Tumorais Cultivadas
6.
J Pharm Biomed Anal ; 43(3): 1106-15, 2007 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-17097257

RESUMO

A method for simultaneous analysis of chloroquine, proguanil and their metabolites from a whole blood sample (80 microL) dried on a filter paper was developed. Sample preparation included a liquid extraction from the filter paper, followed by a solid-phase extraction (C18 Bond Elut cartridge). Separation was obtained by reverse-phase liquid chromatography (HPLC) using a gradient elution on an X-Terra column; UV detection was made at 254 nm. This assay was linear between 150 and 2500 ng mL(-1) for chloroquine (and metabolite) and 300 and 2500 ng mL(-1) for proguanil and cycloguanil. The lower limit of quantification was close to 50 ng mL(-1) for chloroquine (and its metabolite) and 100 ng mL(-1) for proguanil (and its metabolite). No chromatographic interference from endogenous compounds or other tested anti-malarial drugs was evidenced. Chromatographic separation takes about 40 min with a coefficient of variation below 10.3% for within- and between-batch precision. The paper sampling method was validated in 10 healthy subjects treated by Savarine. The stability of compounds and metabolites on the filter paper was evaluated at four temperatures (-20, +4, 20 and 50 degrees C) and for 1, 5 and 20 days. Cycloguanil concentrations were not influenced by storage conditions, whereas, high temperatures and prolonged storage decreased chloroquine and proguanil levels. The proposed HPLC assay is accurate, precise and cost-effective; it can be used for pharmacokinetic and epidemiological studies on anti-malarial treatments.


Assuntos
Antimaláricos/sangue , Cloroquina/análogos & derivados , Cloroquina/sangue , Proguanil/sangue , Triazinas/sangue , Calibragem , Cromatografia Líquida de Alta Pressão , Humanos , Indicadores e Reagentes , Controle de Qualidade , Padrões de Referência , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta
7.
Artigo em Inglês | MEDLINE | ID: mdl-15607719

RESUMO

Pralidoxime methylsulfate (Contrathion) is widely used to treat organophosphate poisoning. Despite animal and human studies, the usefulness of Contrathion therapy remains a matter of debate. Therapeutic dosage regimens need to be clarified and availability of a reliable method for plasma pralidoxime quantification would be helpful in this process. We here describe a high-performance liquid chromatography technique with electrochemical detection to measure pralidoxime concentrations in human serum using guanosine as an internal standard. The assay was linear between 0.25 and 50 microg mL(-1) with a quantification limit of 0.2 microg mL(-1). The analytical precision was satisfactory, with variation coefficients lower 10%. This assay was applied to the analysis of a serum from an organophosphorate poisoned patient and treated by Contrathion infusions (100 and 200 mg h(-1)) after a loading dose (400 mg).


Assuntos
Reativadores da Colinesterase/sangue , Cromatografia Líquida de Alta Pressão/métodos , Eletroquímica/métodos , Compostos de Pralidoxima/sangue , Soluções Tampão , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
8.
Artigo em Inglês | MEDLINE | ID: mdl-12101061

RESUMO

A capillary zone electrophoresis (CZE) technique was developed for the determination of poorly separated monoclonal serum proteins by agarose gel electrophoresis (AGE). A P/ACE 5500 capillary instrument (Beckman) was used under the following conditions: 57 cm x 50 microm I.D. fused-silica capillary, pH 9.6 borate buffer, and 214 nm on-line detection. Sixty patients (61 +/- 13 years) with a well isolated (n=24, group A) or poorly separated monoclonal band(s) by AGE (n=36, group B) were included in this study. Within- and between-run precision for CZE was below 4% for albumin and 7% for gamma-globulin. A 100% (group A) or 61% agreement (group B, more bands detected by CZE in 10 cases) was obtained between CZE and AGE for the number of monoclonal bands. In group B, quantification was possible in 92% of samples by CZE vs. 64% by AGE (P<0.05, chi-square). The proposed CZE method appears as an additional helpful technique for the determination of poorly separated monoclonal serum proteins by AGE.


Assuntos
Proteínas Sanguíneas/análise , Eletroforese Capilar/métodos , Idoso , Proteínas Sanguíneas/isolamento & purificação , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
9.
J Infect Dis ; 200(1): 57-65, 2009 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-19469703

RESUMO

BACKGROUND: We compared sulfadoxine-pyrimethamine (SP) with unsupervised artemether-lumefantrine (AL) and unsupervised amodiaquine-artesunate (ASAQ) fixed-dose formulation for the treatment of uncomplicated malaria in children in Benin. METHODS: This open-label, noninferiority comparative trial included children aged 6-60 months. The follow-up period was 6 weeks, and the primary objective was a comparison of polymerase chain reaction (PCR)-adjusted effectiveness rates at day 28. RESULTS: The study included 240 children (48 received SP, and 96 each received AL and ASAQ). The intention-to-treat analysis showed effectiveness rates on day 28 of 20.8%, 78.1%, and 70.5% for SP, AL, and ASAQ, respectively. After adjustment for PCR results, these rates were 27.1%, 83.3%, and 87.4%, respectively. The per-protocol analysis (217 patients) showed effectiveness rates on day 28 of 21.7%, 88.0%, and 76.1% for SP, AL, and ASAQ, respectively. After adjustment for PCR results, these rates were 28.3%, 94.0%, and 93.2%, respectively. SP was less effective than the other drugs in the PCR-adjusted analysis, whereas AL and ASAQ were equally effective. The rate of new infection was higher among children treated with ASAQ than among those treated with AL. CONCLUSIONS: This was the first trial, to our knowledge, to compare unsupervised AL with unsupervised ASAQ fixed-dose formulation; both treatments provided high PCR-adjusted day 28 effectiveness rates. Efficacy rates for SP were surprisingly low. Clinical trials registration. NCT00460369.


Assuntos
Amodiaquina/uso terapêutico , Antimaláricos/uso terapêutico , Artemisininas/uso terapêutico , Etanolaminas/uso terapêutico , Fluorenos/uso terapêutico , Malária Falciparum/tratamento farmacológico , Pirimetamina/uso terapêutico , Sulfadoxina/uso terapêutico , Animais , Artesunato , Benin , Pré-Escolar , Combinação de Medicamentos , Quimioterapia Combinada , Feminino , Humanos , Lactente , Lumefantrina , Malária Falciparum/prevenção & controle , Malária Falciparum/transmissão , Masculino , Reação em Cadeia da Polimerase
10.
Anticancer Drugs ; 19(3): 295-302, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18510176

RESUMO

Ifosfamide (IFOS) is a bifunctional alkylator with a wide spectrum of activity in solid tumors and has an autoinductive liver metabolism through P450 cytochromes. Autoinduction might permit a better therapeutic index for combination therapy. A phase I trial was investigated with interpatient dose escalation of a single dose of IFOS given every 2 weeks in advanced solid tumor patients. IFOS, its dechloroethylated and active 4-hydroxy metabolites, were measured at cycles 1 and 2 at the end of infusion, 2 and 5 h later, using gas chromatography. IFOS elimination was considered as following monocompartimental model kinetics. The results of 20 patients from January 2004 to June 2006 were included. The median of previous chemotherapies was 2 (0-5). The primary tumor was most often ovarian (5), peritoneal (3), sarcoma (2), melanoma (2) or miscellaneous (8). Ten patients received 2.5 g/m2 and the other 10 patients received 3 g/m2. A total of 79 cycles were evaluable for toxicity. The median number of cycles was 4 (1-8). No grade 3-4 toxicity, no alopecia at first dose level and no toxicity-related fatal events were noted. One objective response was noted in a pancreatic cancer patient and one sustained CA125 decline in a heavily pretreated ovarian cancer patient. A slight (7-10%) but reproducible decrease of areas under the curve was detectable at cycle 2, at both dose levels, related to autoinductive metabolism. Intraindividual variations (large SD) were noticed for each pharmacokinetic parameter. A patient-dependent autoinduction of IFOS metabolism was detected rather than a slight nondose-dependent autoinduction. The toxicity profile allows the development of bi-weekly IFOS-based combination therapies.


Assuntos
Antineoplásicos Alquilantes/administração & dosagem , Ifosfamida/administração & dosagem , Neoplasias/tratamento farmacológico , Adulto , Idoso , Antineoplásicos Alquilantes/efeitos adversos , Antineoplásicos Alquilantes/farmacocinética , Área Sob a Curva , Cromatografia Gasosa , Sistema Enzimático do Citocromo P-450/efeitos dos fármacos , Relação Dose-Resposta a Droga , Indução Enzimática/efeitos dos fármacos , Feminino , Humanos , Ifosfamida/efeitos adversos , Ifosfamida/farmacocinética , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
11.
Nat Med ; 14(12): 1333-42, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19029980

RESUMO

Retinoic acid and arsenic trioxide target the protein stability and transcriptional repression activity of the fusion oncoprotein PML-RARA, resulting in regression of acute promyelocytic leukemia (APL). Phenotypically, retinoic acid induces differentiation of APL cells. Here we show that retinoic acid also triggers growth arrest of leukemia-initiating cells (LICs) ex vivo and their clearance in PML-RARA mouse APL in vivo. Retinoic acid treatment of mouse APLs expressing the fusion protein PLZF-RARA triggers full differentiation, but not LIC loss or disease remission, establishing that differentiation and LIC loss can be uncoupled. Although retinoic acid and arsenic synergize to clear LICs through cooperative PML-RARA degradation, this combination does not enhance differentiation. A cyclic AMP (cAMP)-dependent phosphorylation site in PML-RARA is crucial for retinoic acid-induced PML-RARA degradation and LIC clearance. Moreover, activation of cAMP signaling enhances LIC loss by retinoic acid, identifying cAMP as another potential APL therapy. Thus, whereas transcriptional activation of PML-RARA is likely to control differentiation, its catabolism triggers LIC eradication and long-term remission of mouse APL. Therapy-triggered degradation of oncoproteins could be a general strategy to eradicate cancer stem cells.


Assuntos
Leucemia Promielocítica Aguda/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , AMP Cíclico/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Leucemia Promielocítica Aguda/genética , Leucemia Promielocítica Aguda/patologia , Camundongos , Camundongos Nus , Proteínas de Fusão Oncogênica/genética , Fosforilação , Serina/genética , Serina/metabolismo , Transdução de Sinais , Tretinoína/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Clin Chem ; 49(11): 1909-15, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14578323

RESUMO

BACKGROUND: We evaluated a new, automated multicapillary zone electrophoresis (CE) instrument (Capillarys), 4.51 software version; Sebia) for human serum protein analysis. METHODS: With the Capillarys beta1-beta2+ reagent set, proteins were separated at 7 kV for 4 min in 15.5 cm x 25 micro m fused-silica capillaries (n = 8) at 35.5 degrees C in a pH 10 buffer with online detection at 200 nm. Serum samples with different electrophoretic patterns (n = 265) or potential interference (n = 69) were analyzed and compared with agarose gel electrophoresis (AGE; Hydrasys)-Hyrys, Hydragel protein(e) 15/30 reagent set; Sebia). RESULTS: CVs were <3.5% for albumin, <11% for alpha(1)-globulin, <4.1% for alpha(2)-globulin, <7.4% for beta-globulin, and <5.8% for gamma-globulin (3 control levels); measured throughput was 60 samples/h. In patients without paraprotein (n = 116), the median differences between CE and AGE were -5.4 g/L for albumin, 4.0 g/L for alpha(1)-globulin, 0.7 g/L for alpha(2)-globulin, 0.6 g/L for beta-globulin (P <0.001 for all fractions), and -0.1 g/L for gamma-globulin (not significant). More samples had at least one gamma-migrating peak detected by CE (n = 135 vs 130; paraprotein detection limit, approximately 0.5-0.7 g/L), but fewer were quantified (n = 84 vs 91) because of gamma- to beta-migration shifts. There was a 1.2 g/L median difference between CE and AGE for gamma-migrating paraprotein quantification (n = 69; P <0.001). Several ultraviolet-absorbing substances (lipid emulsion, hemoglobin) or molecules (contrast agent, gelatin-based plasma substitute) induced CE artifacts. CONCLUSIONS: The Capillarys instrument is a reliable CE system for serum protein analysis, combining advantages of full automation (ease of use, bar-code identification, computer-assisted correction of alpha(1)-globulins) with high analytical performances and throughput.


Assuntos
Proteínas Sanguíneas/análise , alfa-Globulinas/análise , Autoanálise , beta-Globulinas/análise , Eletroforese Capilar/métodos , Humanos , Paraproteínas/análise , Albumina Sérica/análise , gama-Globulinas/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA