RESUMO
BACKGROUND: Three scoring methods for the widely available Adult ADHD Symptoms Rating Scale v1.1 (ASRS) have been proposed to screen for ADHD, but these three methods have rarely been compared against formal clinical diagnoses. We aimed to validate the French version of the ASRS against a clinical interview using DSM-IV and DSM-5 diagnostic algorithms. METHODS: One hundred five adults from a convenience sample were evaluated with the ASRS and the DIVA 2.0, using both DSM-IV and DSM-5 criteria. We used Confirmatory Factor Analysis to investigate the underlying structure of the ASRS. Sensitivity, specificity, and classification accuracy were compared between the rating algorithms of the ASRS. RESULTS: The full score method had worse predictive performance than the Screener and the 2-stage scoring method. All characteristics of the three scoring methods for the ASRS were worse when applying DSM-5 criteria. The best-fitting structure was a bi-factor model with a general ADHD factor and three specific factors. CONCLUSIONS: ADHD was best conceived as a one-dimensional construct. The 2-stage scoring method superseded the Screener with comparable sensitivity and specificity.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Adulto , Humanos , Autorrelato , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Psicometria , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Escalas de Graduação PsiquiátricaRESUMO
OBJECTIVE: An external validation of the Wender Utah Rating Scale (WURS) against a clinical assessment is lacking, especially for French-speaking populations. METHOD: Participants completed three subsets of the WURS-61 and were assessed for ADHD using the DIVA 2.0 semi-structured interview. Exploratory factor analyses were performed. Logistic regression models and Receiver-Operating Curves were used to determine the cut-off scores that predicted childhood ADHD with best accuracy. RESULTS: One hundred three adults were included. Three factors were extracted for the WURS-25 and WURS-K, and four for the WURS-29. Cut-off scores are 44, 24 and 42, respectively. When considering DSM-5 rather than DSM-IV criteria, these values changed to 44, 36 and 44, respectively. More than 83% of the participants had been correctly classified. CONCLUSION: All three subsets of the WURS-61 retrospectively predict the presence of ADHD in childhood. This result might prove to be useful in screening and research procedures.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Adulto , Humanos , Estudos Retrospectivos , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Transtorno do Deficit de Atenção com Hiperatividade/epidemiologia , Utah/epidemiologia , Escalas de Graduação Psiquiátrica , Psicometria , Reprodutibilidade dos TestesRESUMO
We report the results of a large-scale (six orchards) and long-term (5-yr) study on seasonal population fluctuations of fruit flies (Diptera Tephritidae) in mango (2005-2009) and cashew (2007-2009) orchards in the Borgou Department, Benin.During the five consecutive years of mango fruit fly monitoring, 25 tephritid species were captured including three species of Bactrocera, 11 of Ceratitis, and 11 of Dacus, which is represented by 2,138,150 specimens in mango orchards. We observed significant differences in Bactrocera dorsalis (Hendel) counts between "high" and "low" mango production years from 2005 to 2008 but not in Ceratitis cosyra (Walker) counts. The native species, C. cosyra, the most abundant species during the dry season, peaked beginning of May, while the exotic species, B. dorsalis, the most abundant species during the rainy season, peaked in June. Preliminary results underlined the role of nine species of wild hosts and seven species of cultivated ones around mango orchards that played an important role in maintaining B. dorsalis in this Sudan zone all year round. The presence of C. cosyra stretched over 9 mo.During the first 14 wk of tephritid monitoring on cashew orchards situated near mango orchards, most flies (62%) were captured in traps positioned in cashew orchards, showing the strong interest of an early fly control on cashew before the mango season. According to these results, in the Sudan zone, effective and compatible control methods as proposed by the IPM package validated by the West African Fruit Fly Initiative project against mango fruit flies are proposed for a large regional tephritid control program in same zones of West Africa.
Assuntos
Anacardium , Mangifera , Tephritidae/fisiologia , Anacardium/crescimento & desenvolvimento , Animais , Benin , Feminino , Frutas/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Mangifera/crescimento & desenvolvimento , Dinâmica Populacional , Estações do Ano , Tephritidae/crescimento & desenvolvimentoRESUMO
BACKGROUND: Benin, a country eligible for Gavi support, changed the presentation of the 13-valent pneumococcal vaccine (PCV13) from the single-dose vial (SDV) to the multi-dose vial (MDV). The present work aims to evaluate the process of making this decision as well as programmatic and logistic impacts. METHODS: WHO protocol for post-introduction evaluation (PIE) was used. Programmatic impact was evaluated by comparing PCV13 coverage and dropout rates with a comparator vaccine administered simultaneously over similar 6-month periods prior to and after the transition. This impact was also appreciated from observation of multi-dose vial management practices during immunization sessions. Logistic impact was measured from the analysis of storage capacities, waste management and vaccine losses. RESULTS: Decision to move to PCV13 MDV was taken at EPI level. Activities planned to support this switch were partially implemented. Impact on vaccination coverage and PCV13 dropout rates in relation with the transition to PCV13 MDV was not detected. The study found that 63% of the health staff surveyed knew and applied WHO's multidose vial policy (MDVP). Vaccines opened vials were found in 83% of health facilities visited. PCV13 MDV (37%) was one of the 3 main vaccines found with open vials in health facility refrigerators. Vaccination risky practices were observed during immunization sessions in 83% of health facilities. The main risky practice was the lack of indication of the date and hour of opening vials (56%). There was a reduction of the volume occupied by vaccines at central store by 47%. Net storage volume per fully immunized child (FIC) decreased from 69.5 to 41 m3. PCV13 MDV allows for 40% reduction in the amount of waste produced by vaccination. PCV13 open vial loss rate has increased from 3 to 7%. CONCLUSION: Benin's experience in transition to an MDV presentation of PCV13 reveals the need for better preparation and planning.
Assuntos
Infecções Pneumocócicas , Vacinas Pneumocócicas , Benin , Criança , Tomada de Decisões , Humanos , Infecções Pneumocócicas/prevenção & controle , Vacinação , Vacinas ConjugadasRESUMO
The shear wave velocity dispersion was analyzed in the Achilles tendon (AT) during passive dorsiflexion using a phase velocity method in order to obtain the tendon shear modulus (C 55). Based on this analysis, the aims of the present study were (i) to assess the reproducibility of the shear modulus for different ankle angles, (ii) to assess the effect of the probe locations, and (iii) to compare results with elasticity values obtained with the supersonic shear imaging (SSI) technique. The AT shear modulus (C 55) consistently increased with the ankle dorsiflexion (N = 10, p < 0.05). Furthermore, the technique showed a very good reproducibility (all standard error of the mean values <10.7 kPa and all coefficient of variation (CV) values ⩽ 0.05%). In addition, independently from the ankle dorsiflexion, the shear modulus was significantly higher in the proximal location compared to the more distal one. The shear modulus provided by SSI was always lower than C55 and the difference increased with the ankle dorsiflexion. However, shear modulus values provided by both methods were highly correlated (R = 0.84), indicating that the conventional shear wave elastography technique (SSI technique) can be used to compare tendon mechanical properties across populations. Future studies should determine the clinical relevance of the shear wave dispersion analysis, for instance in the case of tendinopathy or tendon tear.
Assuntos
Tendão do Calcâneo/fisiologia , Módulo de Elasticidade , Técnicas de Imagem por Elasticidade/métodos , Adulto , Algoritmos , Fenômenos Biomecânicos , Técnicas de Imagem por Elasticidade/normas , Humanos , Masculino , Reprodutibilidade dos TestesRESUMO
A protocol based on ultrafast ultrasonography was developed to study the internal response of isolated perfused human (n=3) and porcine (n=11) kidneys subjected to loading at 0.003 m/s and 0.3m/s respectively. Regional uniaxial strains were calculated based on natural target tracking. The effect of loading speed and regional differences could be statistically detected on the porcine specimens. However, despite the inhomogeneity of their anatomical structures, strains' responses appeared relatively homogeneous at 0.3m/s in both porcine and human kidneys. Failure, identified as a sudden change on the ultrasonography movie, also appeared at similar compression levels for both species (38.3% of applied strain in average for human and 35.8% of applied strain in average for porcine).
Assuntos
Força Compressiva , Rim/diagnóstico por imagem , Rim/fisiologia , Ultrassonografia/métodos , Animais , Desenho de Equipamento , Humanos , Perfusão , Reprodutibilidade dos Testes , Estresse Mecânico , SuínosRESUMO
Thioredoxin (Trx) plays important biological roles both intra- and extracellularly via thiol redox control. We have previously demonstrated that Trx exhibited protective effects against UVA cytotoxicity in human skin fibroblasts. As an extension of the latter investigation, the present work is aimed at assessing ability of Trx to maintain genomic integrity in human skin fibroblasts upon exposure to UVA radiation. Indeed, UVA (320--380 nm) is mutagenic and induces genomic damage to skin cells. The alkaline comet assay was used in association with DNA repair enzyme including formamido pyrimidine glycosylase (Fpg) and endonuclease III (endo III) to estimate the amount of modified bases together with the level of strand breaks and alkali-labile sites. The HPLC-EC assay was applied to assess 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) levels and to permit the calibration of comet assay as previously described. We reported that overexpression of human Trx (transient transfection) as well as exogenous human recombinant Trx added to the culture medium, decreased the level of DNA damage in UVA irradiated cells. Interestingly, transfection appeared to prevent UVA-induced 8-oxodGuo (3.06 au per Joules.cm(-2) compared to 4.94 au per Joules.cm(-2) for nontransfected cells). Moreover, Trx accumulates into nuclei in transfected cells. This finding supports the notion that Trx is important for the maintenance of the integrity of genetic information. This work demonstrated that under conditions of UVA oxidative stress, Trx prevented the UVA-induced DNA damage.
Assuntos
Dano ao DNA , Desoxiguanosina/análogos & derivados , Pele/metabolismo , Pele/efeitos da radiação , Tiorredoxinas/metabolismo , Raios Ultravioleta/efeitos adversos , 8-Hidroxi-2'-Desoxiguanosina , Células Cultivadas , Reparo do DNA , Desoxiguanosina/metabolismo , Desoxiguanosina/efeitos da radiação , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/efeitos da radiação , Radicais Livres/metabolismo , Radicais Livres/efeitos da radiação , Expressão Gênica , Humanos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiação , Proteínas Recombinantes/farmacologia , Pele/efeitos dos fármacos , Tiorredoxinas/genética , Tiorredoxinas/farmacologia , TransfecçãoRESUMO
The present study analyzes the expression of the thioredoxin/thioredoxin reductase (Trx/TR) system in UVA-irradiated human skin fibroblasts. Irradiation increases the intracellular level of Trx and a time-dependent increase of Trx mRNA is observed. Our data indicate that Trx translocates from the cytoplasm to the nucleus. In addition, UV exposure results in an increase in TR synthesis. In order to evaluate the function of Trx/TR system, we investigated the antioxidant role of Trx in transient transfected cells. The ROS accumulation in UVA irradiated cells was assessed using flow cytometry. A 3-fold decrease in ROS production was observed in transiently transfected fibroblasts. These results indicate that Trx acts as an antioxidant protein in UVA irradiated fibroblasts. As ROS are inducers of cell death, this raises the question as to whether Trx is able to protect cells from apoptosis and/or necrosis induced by UVA. Six hours after UVA-irradiation, 29.92% of cells were annexin-V positive. This population was significantly reduced in Trx-transfected cells (8.58%). Moreover, this work demonstrates that Trx prevents the loss of the membrane potential of the mitochondria, the depletion of cellular ATP content, and the loss of cell viability induced by irradiation.
Assuntos
Sobrevivência Celular/fisiologia , Pele/efeitos da radiação , Tiorredoxinas/biossíntese , Trifosfato de Adenosina/metabolismo , Anexina A5/metabolismo , Antioxidantes , Células Cultivadas , Fibroblastos/citologia , Fibroblastos/metabolismo , Fibroblastos/efeitos da radiação , Citometria de Fluxo , Humanos , Potenciais da Membrana/fisiologia , Mitocôndrias/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Pele/citologia , Pele/metabolismo , Tiorredoxina Dissulfeto Redutase/biossíntese , Transfecção , Raios UltravioletaRESUMO
STUDY OBJECTIVES: Early diastolic mitral annular velocity (E') by tissue Doppler echocardiography (TD) has been reported to be a load-independent index of left ventricular (LV) diastolic function, allowing the early diastolic mitral inflow velocity (E)/E' ratio to be used clinically to predict LV filling pressures. However, preload independence of E' has remained controversial, and E/E' may not consistently be predictive of LV filling pressures. Our objectives were to test the hypotheses that E' is affected by preload, and that alterations of preload, afterload, and contractility also affect E/E'. DESIGN, INTERVENTIONS, AND MEASUREMENTS: An open-chest dog model was used (n = 8). High-fidelity pressure and conductance catheters were used for pressure-volume relations, and E' was obtained by pulsed TD from the apical four-chamber view. Changes in preload and afterload were induced by vena caval and partial aortic occlusions, respectively. Data were collected during control phase and during infusions of dobutamine and esmolol to alter contractility. RESULTS: E' was consistently and significantly associated with acute decreases in LV end-diastolic pressure in each dog (n = 200 beats; r = 0.93 +/- 0.06 [mean +/- SD]). Similar results occurred with dobutamine and esmolol infusions. This preload sensitivity was reflected in E/E', which was inversely (rather than directly) correlated with LV diastolic pressure (r = - 0.67). E/E' was less affected by preload when diastolic dysfunction was induced by sustained partial aortic occlusion (time constant of relaxation increased from 46 +/- 19 to 53 +/- 21 ms, p < 0.001). CONCLUSIONS: E' was significantly influenced by preload with preserved LV function and low filling pressures (< 12 mm Hg); accordingly, E/E' was less predictive of LV filling pressures in this scenario. E/E' was more predictive of LV filling pressures in the presence of diastolic dysfunction.
Assuntos
Ecocardiografia Doppler , Valva Mitral/fisiologia , Função Ventricular Esquerda , Animais , Aorta/fisiologia , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea , Diástole , Dobutamina/farmacologia , Cães , Hemodinâmica , Masculino , Valva Mitral/diagnóstico por imagem , Contração Miocárdica/efeitos dos fármacos , Propanolaminas/farmacologia , Volume Sistólico , Veia Cava Inferior/fisiologia , Pressão VentricularRESUMO
"The authors study the phenomenon of illegal immigration in France. After a brief outline of its present situation and dimension, they analyse the political significance of illegal manpower, arriving especially from Africa, Spain and Portugal. "Particular attention is given to government policies oriented at curbing the entry of illegal migrants." (summary in ENG)
Assuntos
Emigração e Imigração , Política Pública , Migrantes , Demografia , Países Desenvolvidos , Europa (Continente) , França , Mão de Obra em Saúde , Política , População , Dinâmica PopulacionalRESUMO
Phosphorylation by Akt on Ser 280 was reported to induce cytoplasmic retention and inactivation of CHK1 with consequent genetic instability in PTEN-/- cells. In acute myeloid leukemia cells carrying the FLT3-internal tandem duplication (ITD) mutation, we observed high rates of FLT3-ITD-dependent CHK1 Ser 280 phosphorylation. Pharmacological inhibition and RNA interference identified Pim1/2, not Akt, as effectors of this phosphorylation. Pim1 catalyzed Ser 280 phosphorylation in vitro and ectopic expression of Pim1/2-induced CHK1 phosphorylation. Ser 280 phosphorylation did not modify CHK1 localization, but facilitated its cell cycle and resistance functions in leukemic cells. FLT3, PIM or CHK1 inhibitors synergized with DNA-damaging agents to induce apoptosis, allowing cells to bypass the etoposide-induced G2/M arrest. Consistently, etoposide-induced CHK1-dependent phosphorylations of CDC25C on Ser 216 and histone H3 on Thr11 were decreased upon FLT3 inhibition. Accordingly, ectopic expression of CHK1 improved the resistance of FLT3-ITD cells and maintained histone H3 phosphorylation in response to DNA damage, whereas expression of unphosphorylated Ser 280Ala mutant did not. Finally, FLT3- and Pim-dependent phosphorylation of CHK1 on Ser 280 was confirmed in primary blasts from patients. These results identify a new pathway involved in the resistance of FLT3-ITD leukemic cells to genotoxic agents, and they constitute the first report of CHK1 Ser 280 regulation in myeloid malignancies.
Assuntos
Leucemia Mieloide Aguda/metabolismo , Proteínas Quinases/metabolismo , Proteínas Proto-Oncogênicas c-pim-1/metabolismo , Linhagem Celular Tumoral , Quinase 1 do Ponto de Checagem , Duplicação Gênica , Humanos , Espaço Intracelular/metabolismo , Leucemia Mieloide Aguda/genética , Fosforilação , Transporte Proteico , Serina/metabolismo , Transdução de Sinais , Tirosina Quinase 3 Semelhante a fms/metabolismoRESUMO
Brain development is a complex phenomenon in which several stages of production, maturation, and organization of neural cells in a network succeed each other. Various environmental factors can disrupt these stages. During the last decade, numerous in vitro and in vivo experimental studies in newborn animal models have established the neurotoxic effects of most anesthetic and sedative drugs used in pediatrics. These effects are essentially responsible for neuronal apoptosis and have been associated with learning disorders in adulthood. This neurotoxicity is time-varying: there is a vulnerability period during synaptogenesis. These toxic effects were attributed to agonist properties on GABA receptors or antagonist properties on NMDA receptors, which are characteristics of all implicated anesthetics. Excessive activation of the GABA pathway and/or excessive inhibition of the NMDA pathway activate cellular mechanisms leading to apoptosis. The intensity of neurotoxic effects is dose- and time-exposure-dependent. These numerous experimental data must be interpreted with caution with regard to their validity in humans, mainly because of interspecies differences as well as differences between experimental conditions and clinical practice. Today, these data are insufficient to change our practices, taking into account the indisputable benefits of the use of anesthetics and sedative drugs. However, progress in experimental research will help us identify the safest therapeutic strategies and neuroprotective treatments.
Assuntos
Anestésicos/efeitos adversos , Encéfalo/embriologia , Encéfalo/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/fisiologia , Cálcio/metabolismo , Citocinas/metabolismo , Relação Dose-Resposta a Droga , Feminino , Humanos , Neurogênese/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Gravidez , Receptores de GABA/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Receptores de Fator de Crescimento Neural/fisiologia , Sinapses/efeitos dos fármacosRESUMO
BACKGROUND: Delay in seeking treatment at the hospital is a major challenge in current Buruli ulcer control; it is associated with severe sequelae and functional limitations. Choosing alternative treatment and psychological, social and practical factors appear to influence delay. Objectives were to determine potential predictors for pre-hospital delay with Leventhal's commonsense model of illness representations, and to explore whether the type of available dominant treatment modality influenced individuals' perceptions about BU, and therefore, influenced pre-hospital delay. METHODOLOGY: 130 healthy individuals aged >18 years, living in BU-endemic areas in Benin without any history of BU were included in this cross-sectional study. Sixty four participants from areas where surgery was the dominant treatment and sixty six participants from areas where antibiotic treatment was the dominant treatment modality were recruited. Using a semi-structured interview we measured illness perceptions (IPQ-R), knowledge about BU, background variables and estimated pre-hospital delay. PRINCIPAL FINDINGS: The individual characteristics 'effectiveness of treatment' and 'timeline acute-chronic' showed the strongest association with pre-hospital delay. No differences were found between regions where surgery was the dominant treatment and regions where antibiotics were the dominant treatment modality. CONCLUSIONS: Individual characteristics, not anticipated treatment modality appeared predictors of pre-hospital delay.
Assuntos
Úlcera de Buruli/tratamento farmacológico , Úlcera de Buruli/cirurgia , Conhecimentos, Atitudes e Prática em Saúde , Aceitação pelo Paciente de Cuidados de Saúde , Adulto , Benin , Estudos Transversais , Feminino , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Adulto JovemRESUMO
OBJECTIVES: Leonetti Law of 2005 concerns procedures for questioning about the appropriateness of initiating or maintaining life-sustaining treatments. Decision of withdrawing and withholding treatment has long been practiced by neonatologists, adult and pediatricians intensivists. In this regard, the recommendations of societies encourage medical teams to assess their practices to improve them. Our evaluation is based on the document of the Ethics Committee of SRLF edited in 2010. TYPE OF STUDY: We achieved a retrospective evaluation of professional practices of the transcription of our decisions of withdrawing and withholding treatment. PATIENTS AND METHODS: This study included all children (95 patients) who have had a questioning about life-sustaining treatment of ICU between March 2008 and August 2011 in the pediatric intensive care unit of Children's Hospital of Lyon. Our evaluation is based on the document of the Ethics Committee of French Society of intensive care (SRLF) edited in 2010. We collected epidemiological data on children concerned by questioning about the appropriateness of initiating or maintaining LST and an evaluation of the transcription of our procedures for LST in our folders. Evaluation included 40 cases: 20 folders randomly selected prior an information meeting (January 2011) which were compared with 20 cases occurred consecutively after this information. This meeting was intended to remind recommendations of good practice and principal points of the law. The main assessment measure was the improvement of the practices respecting criteria of the document of the Ethics Committee of SRLF modified for pediatric care. MAIN RESULTS: Epidemiological data on procedures are comparable to literature data. Concerning the evaluation of our practices before/after a briefing and highlighted a tendency to the improvement without statistically significance. The transcription of reflection and the arguments of decision of withdrawing and withholding treatment and evaluation of pain was the points who need improvement. Finally, despite the positive developments in the therapeutic use of analgesics and sedatives, pain continues to be undervalued. CONCLUSION: The evaluation of professional practices is recommended to improve the procedures of questioning about life-sustaining treatments have become an area of expertise in intensive care.
Assuntos
Unidades de Terapia Intensiva Pediátrica/estatística & dados numéricos , Suspensão de Tratamento/estatística & dados numéricos , Analgésicos/uso terapêutico , Criança , Pré-Escolar , Cuidados Críticos/estatística & dados numéricos , Uso de Medicamentos , Comitês de Ética Clínica , Feminino , Mortalidade Hospitalar , Humanos , Hipnóticos e Sedativos/uso terapêutico , Lactente , Unidades de Terapia Intensiva Pediátrica/ética , Unidades de Terapia Intensiva Pediátrica/legislação & jurisprudência , Tempo de Internação , Cuidados para Prolongar a Vida/estatística & dados numéricos , Masculino , Medição da Dor , Pais , Ordens quanto à Conduta (Ética Médica) , Estudos Retrospectivos , Suspensão de Tratamento/ética , Suspensão de Tratamento/legislação & jurisprudênciaAssuntos
Atitude , Educação , Emprego , Mudança Social , Migrantes , Comportamento , Bélgica , Demografia , Países Desenvolvidos , Economia , Emigração e Imigração , Europa (Continente) , França , Itália , Estado Civil , População , Dinâmica Populacional , Psicologia , Classe Social , Fatores SocioeconômicosRESUMO
Acute myeloid leukemia (AML) cells exposed to genotoxic agents arrest their cell cycle at the G2/M checkpoint and are inherently chemoresistant. To understand the mechanism of this chemoresistance, we compared the ability of immature CD34+ versus mature CD34- AML cell lines (KG1a and U937, respectively) to recover from a DNA damage-induced cell cycle checkpoint in G2. Here, we report that KG1a cells have a more stringent G2/M checkpoint response than U937 cells. We show that in both cell types, the CDC25B phosphatase participates in the G2/M checkpoint recovery and that its expression is upregulated. Furthermore, we show that CHK1 inhibition by UCN-01 in immature KG1a cells allows checkpoint exit and induces sensitivity to genotoxic agents. Similarly, UCN-01 treatment potentializes genotoxic-induced inhibition of colony formation efficiency of primary leukemic cells from AML patients. Altogether, our results demonstrate that checkpoint stringency varies during the maturation process and indicate that targeting checkpoint mechanisms might represent an attractive therapeutic opportunity for chemoresistant immature AML cells.
Assuntos
Divisão Celular , Fase G2 , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Antígenos CD/análise , Antígenos CD34/análise , Antineoplásicos/toxicidade , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Ensaio de Unidades Formadoras de Colônias , Humanos , Mitose/efeitos dos fármacos , Nocodazol/farmacologia , Estaurosporina/análogos & derivados , Estaurosporina/toxicidade , Células U937 , Fosfatases cdc25/metabolismoRESUMO
ATP induced-vasodilation was studied using Striadyne, on pulmonary and systemic arterial bed on 10 patients with stable chronic obstructive pulmonary disease. Such significant effects varied according to the dose: pulmonary vasodilation reached maximal level during low rate infusion (2 mumoles/kg/20 min) and systemic vasodilation was related to the dose. The latter became dominant at maximal dose (5 mumoles/kg/20 min). Simultaneously, on four patients, circulating blood level of ATP was assessed. It increased in proportion with the infusion rate and reached respectively 167% and 149 of baseline level on arterial and mixed venous blood.
Assuntos
Trifosfato de Adenosina/farmacologia , Circulação Pulmonar/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Trifosfato de Adenosina/sangue , Artérias/efeitos dos fármacos , Artérias/fisiologia , Humanos , Cinética , Pessoa de Meia-IdadeRESUMO
The expression of the HIV-1 Tat protein in HeLa cells resulted in a 2.5-fold decrease in the activity of the antioxidant enzyme glutathione peroxidase (GPX). This decrease seemed not to be due to a disturbance in selenium (Se) uptake. Indeed, the intracellular level of Se was similar in parental and tat-transfected cells. A Se enrichment of the medium did not lead to an identical GPX activity in both cell lines, suggesting a disturbance in Se utilization. Total intracellular 75Se selenoproteins were analyzed. Several quantitative differences were observed between parental and tat-transfected cells. Mainly, cytoplasmic glutathione peroxidase and a 15-kDa selenoprotein were decreased in HeLa-tat cells, while phospholipid hydroperoxide glutathione peroxidase and low-molecular-mass selenocompounds were increased. Thioredoxin reductase activity and total levels of 75Se-labeled proteins were not different between the two cell types. The effect of Tat on GPX mRNA levels was also analyzed. Northern blots revealed a threefold decrease in the GPX/glyceraldehyde phosphate dehydrogenase mRNA ratio in HeLa-tat versus wild type cells. By deregulating the intracellular oxidant/antioxidant balance, the Tat protein amplified UV sensitivity. The LD50 for ultraviolet radiation A was 90 J/cm2 for HeLa cells and only 65 J/cm2 for HeLa-tat cells. The oxidative stress occurring in the Tat-expressing cells and demonstrated by the diminished ratio of reduced glutathione/oxidized glutathione was not correlated with the intracellular metal content. Cellular iron and copper levels were significantly decreased in HeLa-tat cells. All these disturbances, as well as the previously described decrease in Mn superoxide dismutase activity, are part of the viral strategy to modify the redox potential of cells and may have important consequences for patients.
Assuntos
Regulação Enzimológica da Expressão Gênica , Produtos do Gene tat/metabolismo , Glutationa Peroxidase/metabolismo , HIV-1 , Tolerância a Radiação/efeitos da radiação , Selênio/metabolismo , Cobre/metabolismo , Produtos do Gene tat/genética , Glutationa/metabolismo , Glutationa Peroxidase/genética , HIV-1/fisiologia , Células HeLa , Humanos , Ferro/metabolismo , Dose Letal Mediana , Peso Molecular , Oxirredução , Estresse Oxidativo , Peróxidos/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase , Proteínas/química , Proteínas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Selênio/toxicidade , Selenoproteínas , Tiorredoxina Dissulfeto Redutase/metabolismo , Oligoelementos/metabolismo , Raios Ultravioleta , Produtos do Gene tat do Vírus da Imunodeficiência HumanaRESUMO
Human fibroblasts and keratinocytes possess nitric oxide synthases (NOS), which metabolize L-arginine (L-Arg) for producing nitric oxide (NO*). This report delineates the relations between NO* and UVA in the human keratinocyte cell line HaCaT. NOS activity was stimulated by exposure of cells to L-Arg just after irradiation. L-Arg (5 mM) supply led to an increase in UVA (25.3 J/cm(2)) cytotoxicity (% of viability 18 +/- 3%) whereas neither L-Arg itself nor UVA irradiation induced cell death at the doses used in this study. Cells were also treated either with L-thiocitrulline (L-Thio), an irreversible inhibitor of NOS, or with exogenous superoxide dismutase (SOD) and catalase. L-Thio and SOD prevented L-Arg-mediated deleterious effects in irradiated cells, whereas catalase was ineffective. Intracellular antioxidant enzyme activities were also determined. UVA/L-Arg stress altered catalase (66% decrease) and glutathione peroxidase (83% decrease). DNA damage was evaluated using the 'comet assay' and quantified using the 'tail moment'. UVA alone was genotoxic (mean tail moment: 25.43 +/- 1.23, P<0.001 compared control cells). The addition of L-Arg potentiated DNA damage (mean tail moment: 41.05+/-3.9) whereas L-Thio prevented them (mean tail moment 9.86 +/- 0.98). We attempted to assess the effect of poly(ADP-ribose) polymerase (PARP) inhibition on cell death. Using the PARP inhibitor 3-aminobenzamide, we established that PARP determines both cell lysis and DNA damage induced by UVA and/or L-Arg. Our findings demonstrated that L-Arg was able to increase UVA-mediated deleterious effects in keratinocytes (both DNA damage and cytotoxicity) and that the ratio NO*/O2*- plays a key role in these processes.