Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 104
Filtrar
1.
Philos Trans A Math Phys Eng Sci ; 382(2273): 20230197, 2024 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-38736334

RESUMO

The origin of micrometeorites (MMs) from asteroids and comets is well-established, but the relative contribution from these two classes remains poorly resolved. Likewise, determining the precise origin of individual MMs is an open challenge. Here, cosmic-ray exposure ages are used to resolve the spatial origins of 12 MMs collected from urban areas and Antarctica. Their 26Al and 10Be concentration, produced during cosmic-ray irradiation in space, were measured by accelerator mass spectrometry. These data are compared to results from a model simulating the transport and irradiation of the MM precursors in space. This model, for the first time, considers a variety of orbits, precursor particle sizes, compositions and densities and incorporates non-isotropic solar and galactic cosmic-ray flux profiles, depth-dependent production rates, as well as spherical evaporation during atmospheric entry. While the origin for six MMs remains ambiguous, two MMs show a preferential tendency towards an origin in the Inner Solar System (Near Earth Objects to the Asteroid Belt) and four towards an origin in the Outer Solar System (Jupiter Family Comets to the Kuiper Belt). These findings challenge the notion that dust originating from the Outer Solar System is unlikely to survive long-term transport and delivery to the terrestrial planets. This article is part of the theme issue 'Dust in the Solar System and beyond'.

2.
Tectonics ; 37(12): 4535-4566, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31007340

RESUMO

We present an extensive study of rehomogenized olivine-hosted melt inclusions, olivine phenocrysts, and chromian spinel inclusions to explore the link between geodynamic conditions and the origin and composition of Pliocene-Quaternary intraplate magmatism in Anatolia at Kula, Ceyhan-Osmaniye, and Karacadag. Exceptional compositional variability of these products reveals early and incomplete mixing of distinct parental melts in each volcanic center, reflecting asthenospheric and lithospheric mantle sources. The studied primitive magmas consist of (1) two variably enriched ocean island basalt (OIB)-type melts in Kula; (2) both OIB-type and plume mid-ocean ridge basalt (P-MORB)-like melts beneath Toprakkale and Üçtepeler (Ceyhan-Osmaniye); and (3) two variably enriched OIB-type melts beneath Karacadag. Estimated conditions of primary melt generation are 23-9 kbar, 75-30 km, and 1415-1215 °C for Kula; 28-19 kbar, 90-65 km, and 1430-1350 °C for Toprakkale; 23-18 kbar, 75-60 km, and 1400-1355 °C for Üçtepeler; and 35-27 kbar, 115-90 km, and 1530-1455 °C for Karacadag, the deepest levels of which correspond to the depth of the lithosphere-asthenosphere boundary in all regions. Although magma ascent was likely facilitated by local deformation structures, recent Anatolian intraplate magmatism seems to be triggered by large-scale mantle flow that also affects the wider Arabian and North African regions. We infer that these volcanics form part of a much wider Arabian-North African intraplate volcanic province, which was able to invade the Anatolian upper plate through slab gaps.

3.
J Hum Nutr Diet ; 27 Suppl 2: 152-9, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23682834

RESUMO

BACKGROUND: In the context of a rapidly increasing prevalence of noncommunicable diseases, fruit and vegetables could play a key preventive role. To date, there is no rapid assessment tool available for measuring the fruit and vegetable intakes of North-African women. The present study aimed to investigate the reproducibility and relative validity of an eight-item quantitative food frequency questionnaire that measures the fruit and vegetable intakes (FV-FFQ) of Moroccan women. METHODS: During a 1-week period, 100 women, living in the city of Rabat, Morocco (aged 20-49 years) completed the short FV-FFQ twice: once at baseline (FV-FFQ1) and once at the end of the study (FV-FFQ2). In the mean time, participants completed three 24-h dietary recalls. All questionnaires were administered by interviewers. Reproducibility was assessed by computing Spearman's correlation coefficients, intraclass correlation (ICC) coefficients and kappa statistics. Relative validity was assessed by computing Wilcoxon signed-rank tests and Spearman's correlation coefficients, as well as by performing Bland-Altman plots. RESULTS: In terms of reproducibility, Spearman's correlation coefficient was 0.56; ICC coefficient was 0.68; and weighted kappa was 0.35. In terms of relative validity, compared with the three 24-h recalls, the FV-FFQ slightly underestimated mean fruit and vegetable intakes (-10.9%; P = 0.006); Spearman's correlation coefficient was 0.69; at the individual level, intakes measured by the FV-FFQ were between 0.39 and 2.19 times those measured by the 24-h recalls. CONCLUSIONS: The brief eight-item FV-FFQ is a reliable and relatively valid tool for measuring mean fruit and vegetable intakes at the population level, although this is not the case at the individual level.


Assuntos
Comportamento Alimentar , Frutas , Inquéritos e Questionários , Verduras , Adulto , Bases de Dados Factuais , Registros de Dieta , Estudos de Avaliação como Assunto , Feminino , Humanos , Rememoração Mental , Pessoa de Meia-Idade , Marrocos , Reprodutibilidade dos Testes , Estudos Retrospectivos , Adulto Jovem
4.
Differentiation ; 84(5): 355-65, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23142731

RESUMO

Cellular systems implanted into an injured nerve may produce growth factors or extracellular matrix molecules, modulate the inflammatory process and eventually improve nerve regeneration. In the present study, we evaluated the therapeutic value of human umbilical cord matrix MSCs (HMSCs) on rat sciatic nerve after axonotmesis injury associated to Vivosorb® membrane. During HMSCs expansion and differentiation in neuroglial-like cells, the culture medium was collected at 48, 72 and 96 h for nuclear magnetic resonance (NMR) analysis in order to evaluate the metabolic profile. To correlate the HMSCs ability to differentiate and survival capacity in the presence of the Vivosorb® membrane, the [Ca(2+)]i of undifferentiated HMSCs or neuroglial-differentiated HMSCs was determined by the epifluorescence technique using the Fura-2AM probe. The Vivosorb® membrane proved to be adequate and used as scaffold associated with undifferentiated HMSCs or neuroglial-differentiated HMSCs. In vivo testing was carried out in adult rats where a sciatic nerve axonotmesis injury was treated with undifferentiated HMSCs or neuroglial differentiated HMSCs with or without the Vivosorb® membrane. Motor and sensory functional recovery was evaluated throughout a healing period of 12 weeks using sciatic functional index (SFI), extensor postural thrust (EPT), and withdrawal reflex latency (WRL). Stereological analysis was carried out on regenerated nerve fibers. In vitro investigation showed the formation of typical neuroglial cells after differentiation, which were positively stained for the typical specific neuroglial markers such as the GFAP, the GAP-43 and NeuN. NMR showed clear evidence that HMSCs expansion is glycolysis-dependent but their differentiation requires the switch of the metabolic profile to oxidative metabolism. In vivo studies showed enhanced recovery of motor and sensory function in animals treated with transplanted undifferentiated and differentiated HMSCs that was accompanied by an increase in myelin sheath. Taken together, HMSC from the umbilical cord Wharton jelly might be useful for improving the clinical outcome after peripheral nerve lesion.


Assuntos
Transplante de Células-Tronco Mesenquimais , Regeneração Nervosa , Poliésteres/uso terapêutico , Animais , Antígenos Nucleares/análise , Diferenciação Celular , Linhagem Celular , Proteína GAP-43/análise , Proteína Glial Fibrilar Ácida/análise , Glicólise , Humanos , Espectroscopia de Ressonância Magnética , Membranas Artificiais , Células-Tronco Mesenquimais/citologia , Atividade Motora , Bainha de Mielina/metabolismo , Compressão Nervosa , Proteínas do Tecido Nervoso/análise , Neuroglia/citologia , Traumatismos dos Nervos Periféricos/terapia , Ratos , Nervo Isquiático/química , Nervo Isquiático/fisiologia , Nervo Isquiático/cirurgia , Sensação , Geleia de Wharton/citologia
5.
J Pharm Biomed Anal ; 49(2): 295-303, 2009 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-19135817

RESUMO

Angiotensin-converting enzyme (ACE) inhibitors are a group of active substances binding to an active site of ACE. Many authors who studied the structure activity relationship suggested the structural elements needed for a potent ACE inhibitor. While many authors studied the activity of ACE inhibitor substances only a few structure stability studies have been presented. In this paper the stability properties of molecule xPRIL were studied by determination of degradation path and rate of degradation in aqueous solutions with different pH (2.0, 6.8 and 12.0) and temperatures (40, 60 and 80 degrees C). The degradation of molecule through two main degradation paths was identified and confirmed by liquid chromatography and mass spectroscopy (LC-MS). Stability properties of xPRIL were determined in a stability study evaluated by high-performance liquid chromatography (HPLC). The first order kinetics of degradation reaction of xPRIL and Arrhenius equations for each pH were determined at observed conditions. xPRIL showed the highest stability at pH 2 solution. The degradation kinetics of xPRIL was compared to the degradation kinetics of enalapril maleate (EM) and perindopril (PER) in bio relevant solutions with pH 2.0 and 6.8. In addition to the stability study of xPRIL the forced degradation study of all three molecules at rigorous conditions was conducted. From the obtained results the structural element having the highest influence on stability properties of the studied molecules was identified. The fragmentation paths of xPRIL, its cyclization degradation product and its hydrolysis degradation product were identified and confirmed by MS/MS method.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/química , Água/química , Sítios de Ligação , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Estabilidade de Medicamentos , Enalapril/química , Guias como Assunto , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Espectrometria de Massas/métodos , Modelos Biológicos , Estrutura Molecular , Perindopril/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Soluções , Espectrometria de Massas em Tandem/métodos , Temperatura
6.
Int J Popul Data Sci ; 4(1): 581, 2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-34095527

RESUMO

INTRODUCTION: Excessive alcohol consumption has adverse effects on health and there is a recognised need for the longitudinal analysis of population data to improve our understanding of the patterns of alcohol use, harms to consumers and those in their immediate environment. The UK has a number of linkable, longitudinal databases that if assembled properly could support valuable research on this topic. AIMS AND OBJECTIVES: This paper describes the development of a broad set of cross-linked cohorts, e-cohorts, surveys and linked electronic healthcare records (EHRs) to construct an alcohol-specific analytical platform in the United Kingdom using datasets on the population of Wales.The objective of this paper is to provide a description of existing key datasets integrated with existing, routinely collected electronic health data on a secure platform, and relevant derived variables to enable population-based research on alcohol-related harm in Wales. We illustrate our use of these data with some exemplar research questions that are currently under investigation. METHODS: Record-linkage of routine and observational datasets. Routine data includes hospital admissions, general practice, and cohorts specific to children. Two observational studies were included. Routine socioeconomic descriptors and mortality data were also linked. CONCLUSION: We described a record-linked, population-based research protocol for alcohol related harm on a secure platform. As the datasets used here are available in many countries, ELAStiC provides a template for setting up similar initiatives in other countries. We have also defined a number of alcohol specific variables using routinely-collected available data that can be used in other epidemiological studies into alcohol related outcomes. With over 10 years of longitudinal data, it will help to understand alcohol-related disease and health trajectories across the lifespan.

7.
Sci Adv ; 5(12): eaay2670, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31897430

RESUMO

The cellular and the molecular mechanisms by which long noncoding RNAs (lncRNAs) may regulate presynaptic function and neuronal activity are largely unexplored. Here, we established an integrated screening strategy to discover lncRNAs implicated in neurotransmitter and synaptic vesicle release. With this approach, we identified neuroLNC, a neuron-specific nuclear lncRNA conserved from rodents to humans. NeuroLNC is tuned by synaptic activity and influences several other essential aspects of neuronal development including calcium influx, neuritogenesis, and neuronal migration in vivo. We defined the molecular interactors of neuroLNC in detail using chromatin isolation by RNA purification, RNA interactome analysis, and protein mass spectrometry. We found that the effects of neuroLNC on synaptic vesicle release require interaction with the RNA-binding protein TDP-43 (TAR DNA binding protein-43) and the selective stabilization of mRNAs encoding for presynaptic proteins. These results provide the first proof of an lncRNA that orchestrates neuronal excitability by influencing presynaptic function.


Assuntos
Proteínas de Ligação a DNA/metabolismo , RNA Longo não Codificante/metabolismo , Vesículas Sinápticas/metabolismo , Animais , Movimento Celular/genética , Proteínas de Ligação a DNA/genética , Células HEK293 , Hipocampo/citologia , Humanos , Camundongos , Camundongos Transgênicos , Neurogênese/genética , Neurônios/metabolismo , Neurotransmissores/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Transfecção
8.
Int J Pharm ; 356(1-2): 200-5, 2008 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-18304767

RESUMO

Perindopril Erbumine (PER) is one of the newly used angiotensin-converting enzyme inhibitors (ACE inhibitors) and is used for the treatment of patients with hypertension and symptomatic heart failure. It has two main degradation pathways, i.e. the degradation by hydrolysis and the degradation by cyclization. An isothermal heat conduction microcalorimetry (MC) and high pressure liquid chromatography (HPLC) were used for the characterization of aqueous solutions of PER and its stability properties. The rates of heat evolved during degradation of perindopril were measured by MC as a function of temperature and pH and from these data rate constant and change in enthalpy of the reactions were determined. With the HPLC method the concentration of perindopril and its degradation products were measured as a function of time in aqueous solutions of different pH that were stored at different temperatures. We demonstrated that reactions of degradation of perindopril at observed conditions follow the first order kinetics. The Arrhenius equation for each pH was determined. At pH 6.8 only one degradation pathway is present, i.e. the degradation by hydrolysis. Degradation constants for this pathway calculated from MC data are in good agreement with those obtained from HPLC. MC as a non-specific technique was shown to be useful in studies of PER when one reaction was present in the sample and also when more chemical and physical processes were simultaneously running.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/química , Perindopril/química , Termodinâmica , Calorimetria/métodos , Química Farmacêutica , Cromatografia Líquida de Alta Pressão/métodos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Concentração de Íons de Hidrogênio , Cinética , Soluções Farmacêuticas
9.
Curr Biol ; 11(21): 1722-7, 2001 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-11696333

RESUMO

In mammals, one of the key regulators necessary for responding to genotoxic stress is the p53 transcription factor. p53 is the single most commonly mutated tumor suppressor gene in human cancers. Here we report the identification of a C. elegans homolog of mammalian p53. Using RNAi and DNA cosuppression technology, we show that C. elegans p53 (cep-1) is required for DNA damage-induced apoptosis in the C. elegans germline. However,cep-1 RNAi does not affect programmed cell death occurring during worm development and physiological (radiation-independent) germ cell death. The DNA binding domain of CEP-1 is related to vertebrate p53 members and possesses the conserved residues most frequently mutated in human tumors. Consistent with this, CEP-1 acts as a transcription factor and is able to activate a transcriptional reporter containing consensus human p53 binding sites. Our data support the notion that p53-mediated transcriptional regulation is part of an ancestral pathway mediating DNA damage-induced apoptosis and reveals C. elegans as a genetically tractable model organism for studying the p53 apoptotic pathway.


Assuntos
Apoptose , Proteínas de Caenorhabditis elegans/metabolismo , Dano ao DNA , Fatores de Transcrição/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Sequência de Aminoácidos , Animais , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Sequência Conservada , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Fatores de Transcrição/genética , Proteína Supressora de Tumor p53/genética
10.
Curr Biol ; 11(24): 1934-44, 2001 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-11747819

RESUMO

BACKGROUND: In response to genotoxic stress, cells activate checkpoint pathways that lead to a transient cell cycle arrest that allows for DNA repair or to apoptosis, which triggers the demise of genetically damaged cells. RESULTS: During positional cloning of the C. elegans rad-5 DNA damage checkpoint gene, we found, surprisingly, that rad-5(mn159) is allelic with clk-2(qm37), a mutant previously implicated in regulation of biological rhythms and life span. However, clk-2(qm37) is the only C. elegans clock mutant that is defective for the DNA damage checkpoint. We show that rad-5/clk-2 acts in a pathway that partially overlaps with the conserved C. elegans mrt-2/S. cerevisiae RAD17/S. pombe rad1(+) checkpoint pathway. In addition, rad-5/clk-2 also regulates the S phase replication checkpoint in C. elegans. Positional cloning reveals that the RAD-5/CLK-2 DNA damage checkpoint protein is homologous to S. cerevisiae Tel2p, an essential DNA binding protein that regulates telomere length in yeast. However, the partial loss-of-function C. elegans rad-5(mn159) and clk-2(qm37) checkpoint mutations have little effect on telomere length, and analysis of the partial loss-of-function of S. cerevisiae tel2-1 mutant failed to reveal typical DNA damage checkpoint defects. CONCLUSIONS: Using C. elegans genetics we define the novel DNA damage checkpoint protein RAD-5/CLK-2, which may play a role in oncogenesis. Given that Tel2p has been shown to bind to a variety of nucleic acid structures in vitro, we speculate that the RAD-5/CLK-2 checkpoint protein may act at sites of DNA damage, either as a sensor of DNA damage or to aid in the repair of damaged DNA.


Assuntos
Adenosina Trifosfatases , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Dano ao DNA , Proteínas Fúngicas/metabolismo , Proteínas de Saccharomyces cerevisiae , Proteínas de Ligação a Telômeros , Alelos , Sequência de Aminoácidos , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/química , DNA Helicases , Epistasia Genética , Evolução Molecular , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Humanos , Dados de Sequência Molecular , Mutação , Homologia de Sequência de Aminoácidos
11.
Mol Cell Biol ; 13(4): 2069-80, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8455599

RESUMO

Protein phosphorylation plays an important role in pheromone-induced differentiation processes of haploid yeast cells. Among the components necessary for signal transduction are the STE7 and STE11 kinases and either one of the redundant FUS3 and KSS1 kinases. FUS3 and presumably KSS1 are phosphorylated and activated during pheromone induction by a STE7-dependent mechanism. Pheromone also induces the accumulation of STE7 in a hyperphosphorylated form. This modification of STE7 requires the STE11 kinase, which is proposed to act before STE7 during signal transmission. Surprisingly, STE7 hyperphosphorylation also requires a functional FUS3 (or KSS1) kinase. Using in vitro assays for FUS3 phosphorylation, we show that pheromone activates STE7 even in the absence of FUS3 and KSS1. Therefore, STE7 activation must precede modification of FUS3 (and KSS1). These findings suggest that STE7 hyperphosphorylation is a consequence of its activation but not the determining event.


Assuntos
MAP Quinase Quinase Quinases , Proteínas Quinases Ativadas por Mitógeno , Peptídeos/fisiologia , Feromônios/fisiologia , Fosfoproteínas/metabolismo , Proteínas Quinases/metabolismo , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Western Blotting , Clonagem Molecular , Proteínas Fúngicas/metabolismo , Fator de Acasalamento , Quinases de Proteína Quinase Ativadas por Mitógeno , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos/química , Fosforilação , Proteínas Tirosina Quinases/metabolismo , Transdução de Sinais
12.
Mol Cell Biol ; 18(7): 3681-91, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9632750

RESUMO

In yeast, the pheromone alpha-factor acts as an antiproliferative factor that induces G1 arrest and cellular differentiation. Previous data have indicated that Far1, a factor dedicated to pheromone-induced cell cycle arrest, is under positive and negative posttranslational regulation. Phosphorylation by the pheromone-stimulated mitogen-activated protein (MAP) kinase Fus3 has been thought to enhance the binding of Far1 to G1-specific cyclin-dependent kinase (Cdk) complexes, thereby inhibiting their catalytic activity. Cdk-dependent phosphorylation events were invoked to account for the high instability of Far1 outside early G1 phase. To confirm any functional role of Far1 phosphorylation, we undertook a systematic mutational analysis of potential MAP kinase and Cdk recognition motifs. Two putative phosphorylation sites that strongly affect Far1 behavior were identified. A change of serine 87 to alanine prevents the cell cycle-dependent degradation of Far1, causing enhanced sensitivity to pheromone. In contrast, threonine 306 seems to be an important recipient of an activating modification, as substitutions at this position abolish the G1 arrest function of Far1. Only the phosphorylated wild-type Far1 protein, not the T306-to-A substitution product, can be found in stable association with the Cdc28-Cln2 complex. Surprisingly, Far1-associated Cdc28-Cln2 complexes are at best moderately inhibited in immunoprecipitation kinase assays, suggesting unconventional inhibitory mechanisms of Far1.


Assuntos
Proteína Quinase CDC28 de Saccharomyces cerevisiae/metabolismo , Proteínas de Ciclo Celular , Ciclinas/metabolismo , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/farmacologia , Fase G1 , Inibidores do Crescimento/farmacologia , Lipoproteínas/farmacologia , Feromônios/farmacologia , Proteínas Repressoras , Proteínas de Saccharomyces cerevisiae , Animais , Sítios de Ligação , Proteína Quinase CDC28 de Saccharomyces cerevisiae/antagonistas & inibidores , Divisão Celular , Proteínas Inibidoras de Quinase Dependente de Ciclina , Ciclinas/antagonistas & inibidores , Ciclinas/genética , Inibidores Enzimáticos/metabolismo , Proteínas Fúngicas/genética , Genes myc , Histidina , Camundongos , Mutagênese , Fosforilação , Serina/genética , Serina/metabolismo , Treonina/genética , Treonina/metabolismo , Tripeptidil-Peptidase 1
13.
Int J Pharm ; 342(1-2): 145-51, 2007 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-17597314

RESUMO

The stability properties of enalapril maleate (EM) and of different tablet formulations including EM were studied by isothermal microcalorimetry and by high performance liquid chromatography (HPLC). It was shown that water content of the sample and elevated temperature have a high impact on stability properties of the substance itself and of the formulations including this substance. The degradation is more extensive at higher water content and at elevated temperature. The type of the tablet formulation (5 or 20mg EM tablet formulation) also has an impact: the 5 EM tablet formulation is the less stable one. The heat output of individual tablet formulations was used to evaluate the enthalpy changes and to calculate the difference in the amount of degraded EM between various samples. These results agreed satisfactorily with those obtained by HPLC. Isothermal microcalorimetry proved to be a fast and predictive method that could be used in preformulation studies to accelerate the pharmaceutical development and shorten the time before launching the product to the market.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/química , Enalapril/química , Varredura Diferencial de Calorimetria , Química Farmacêutica , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Pós , Comprimidos , Termodinâmica , Água/análise
14.
Cell Death Differ ; 12(2): 153-61, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15605074

RESUMO

The p53 tumor suppressor promotes apoptosis in response to DNA damage. Here we describe the Caenorhabditis elegans gene ced-13, which encodes a conserved BH3-only protein. We show that ced-13 mRNA accumulates following DNA damage, and that this accumulation is dependent on an intact C. elegans cep-1/p53 gene. We demonstrate that CED-13 protein physically interacts with the antiapoptotic Bcl-2-related protein CED-9. Furthermore, overexpression of ced-13 in somatic cells leads to the death of cells that normally survive, and this death requires the core apoptotic pathway of C. elegans. Recent studies have implicated two BH3-only proteins, Noxa and PUMA, in p53-induced apoptosis in mammals. Our studies suggest that in addition to the BH3-only protein EGL-1, CED-13 might also promote apoptosis in the C. elegans germ line in response to p53 activation. We propose that an evolutionarily conserved pathway exists in which p53 promotes cell death by inducing expression of two BH3-only genes.


Assuntos
Apoptose/fisiologia , Proteínas de Caenorhabditis elegans/fisiologia , Caenorhabditis elegans/fisiologia , Dano ao DNA , Sequência de Aminoácidos , Animais , Proteínas Reguladoras de Apoptose , Caenorhabditis/genética , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , DNA/genética , DNA/efeitos da radiação , Deleção de Genes , Regulação da Expressão Gênica no Desenvolvimento/efeitos da radiação , Proteínas de Choque Térmico/genética , Modelos Biológicos , Dados de Sequência Molecular , Mutação , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2 , Proteínas Repressoras/genética , Homologia de Sequência de Aminoácidos , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/fisiologia , Raios X
15.
Biochim Biophys Acta ; 1492(1): 139-44, 2000 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-10858540

RESUMO

Stimulation by the ganglioside IV(3)NeuAc-nLcOse(4)Cer leads to growth arrest in the Burkitt lymphoma cell line Raji. In order to analyze the primary response of Raji cells to that stimulus, a cDNA array screen and a suppression subtractive hybridization-PCR approach were performed. Twenty-four genes with assigned functions were confirmed to be induced by the ganglioside in reverse Northern blot experiments covering e.g. protein kinase B, phospholipase C, the MAP-kinase ERK3, the transcription factors YY1, DR1 and NSEP, the membrane traffic protein TAP, and the nuclear export protein CRM1. Most of the genes identified are involved in signal transduction, transcription, and cell trafficking. For selected genes, the induction of expression was quantified by semiquantitative RT-PCR.


Assuntos
Linfoma de Burkitt/patologia , Movimento Celular/efeitos dos fármacos , Gangliosídeos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Linfoma de Burkitt/genética , Divisão Celular/efeitos dos fármacos , Divisão Celular/genética , Movimento Celular/genética , Transformação Celular Neoplásica , Replicação do DNA/efeitos dos fármacos , DNA Complementar/efeitos dos fármacos , DNA Complementar/isolamento & purificação , Genes Neoplásicos/efeitos dos fármacos , Genes Neoplásicos/genética , Humanos , Transdução de Sinais/genética , Células Tumorais Cultivadas
16.
Biochim Biophys Acta ; 804(4): 398-403, 1984 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-6087922

RESUMO

It is now well established that human lymphoblastoid cell lines showing immaturity characters display ecto-5'-nucleotidase activities lower than normal levels. A recent paper (Sun, A.S., Holland, J.F. and Ohnuma, T. (1983) Biochim. Biophys. Acta 762, 577-584) mentioned that this phenomenon resulted from the presence of a 5'-nucleotidase inhibitor in these cell lines. We demonstrate here that the use of 5'-[3H]AMP as a substrate, and inadequate analysis of the products formed, led them to a misinterpretation. [3H]Adenosine derived from 5'-[3H]AMP hydrolysis was further transformed into [3H]inosine by the adenosine deaminase activity of the leukemic cell lines tested; [3H]inosine was precipitated with the excess substrate and was not taken into account in the ecto-5'-nucleotidase determination, which led the authors to confuse this adenosine deaminase activity with a 5'-nucleotidase inhibitor. We did not observe 5'-nucleotidase inhibition by leukemic cell cytosol when convenient assay methods were used and showed that the presence of such an inhibitor remains to be established.


Assuntos
Adenosina/metabolismo , Leucemia/enzimologia , Nucleotidases/antagonistas & inibidores , 5'-Nucleotidase , Adenosina Desaminase/metabolismo , Monofosfato de Adenosina/metabolismo , Humanos , Inosina/metabolismo
17.
J Mol Biol ; 191(1): 143-5, 1986 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-3795272

RESUMO

The purification of bovine lactoferrin, its crystallization at low ionic strength, and preliminary X-ray crystallographic data are reported. The crystals, which grow from a two-phase system, are radiation-stable and suitable for a medium-resolution X-ray analysis. They are orthorhombic, space group P2(1)2(1)2(1), with cell dimensions a = 138.4 A, b = 87.1 A, c = 73.6 A, and one protein molecule in the asymmetric unit.


Assuntos
Lactoferrina , Lactoglobulinas , Animais , Bovinos , Colostro/metabolismo , Cristalografia , Feminino , Humanos , Lactoferrina/isolamento & purificação , Lactoglobulinas/isolamento & purificação , Gravidez
18.
Arch Gen Psychiatry ; 48(8): 720-8, 1991 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1883255

RESUMO

The multiaxial nature of DSM-III has stimulated interest in the personality disorders. There are also indications that it has produced an increase in their diagnosis. However, there is clinical and psychometric evidence that a personality evaluation undertaken while a patient is in a dysphoric mental state may distort or misrepresent traits, the so-called trait-state problem in personality assessment. The present study appears to be the first to investigate this phenomenon with a clinical interview rather than with personality tests. It examined the effect of anxiety, depression, and level of global impairment on the diagnosis of personality disorder and the assessment of the criteria for the individual Axis II disorders. Eighty-four patients, most of whom had current Axis I diagnoses, were evaluated by seven experienced clinicians with a new semistructured interview, the Personality Disorder Examination. The sample evidenced a trend toward acknowledging fewer maladaptive personality traits at follow-up than at entry. There was no evidence, however, that anxiety or depression had affected either the diagnosis of a personality disorder or the criteria associated with most of the individual personality disorders.


Assuntos
Transtornos da Personalidade/diagnóstico , Adolescente , Adulto , Transtornos de Ansiedade/complicações , Transtornos de Ansiedade/psicologia , Transtorno Depressivo/complicações , Transtorno Depressivo/psicologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Determinação da Personalidade/estatística & dados numéricos , Transtornos da Personalidade/complicações , Transtornos da Personalidade/psicologia , Escalas de Graduação Psiquiátrica/estatística & dados numéricos
19.
Gene ; 275(1): 157-62, 2001 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-11574164

RESUMO

A human homologue of the murine zinc finger protein zfr is transcriptionally induced in the Epstein-Barr virus-positive Burkitt lymphoma cell line Raji upon treatment with the granulocyte/macrophage lineage ganglioside IV(3)NeuAc-nLcOse(4)Cer. The gene was cloned by a rapid amplification of cDNA ends approach based on a cDNA clone. The resulting hzfr sequence is 3393 base pairs in length coding for a protein of 1057 amino acids. Sequence alignments between hzfr and zfr reveal an identity of 92% on the nucleotide level and an identity of 96.4% on the amino acid level, respectively. Based on Southern blot data hzfr can be addressed as a single copy gene. Tissue-specific expression was determined by semi-quantitative PCR of normalized cDNA populations from various human tissues with glyceraldehyde-3-phosphate dehydrogenase as an internal control. Highest levels of transcripts were found in brain. hzfr transcripts could not be detected in skeletal muscle.


Assuntos
Proteínas de Ligação a RNA/genética , Sequência de Aminoácidos , Animais , Southern Blotting , Clonagem Molecular , DNA/genética , DNA Complementar/química , DNA Complementar/genética , Feminino , Gangliosídeos/farmacologia , Dosagem de Genes , Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Dados de Sequência Molecular , RNA/genética , RNA/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Distribuição Tecidual , Células Tumorais Cultivadas
20.
Am J Psychiatry ; 146(12): 1585-91, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2589552

RESUMO

The authors conducted a systematic examination of DSM-III-R personality disorders among 35 patients with eating disorders. Fifty-seven percent of the patients met the criteria for at least one axis II diagnosis; borderline, self-defeating, and avoidant were the most frequently assigned personality disorders. Forty percent of the patients were given two or more diagnoses, and 17% of the patients met criteria for five to seven diagnoses. No differences were found between patients with anorexia nervosa, anorexia and bulimia nervosa, and bulimia nervosa in the distribution of diagnoses or the frequency with which individual criteria (traits) were assigned.


Assuntos
Anorexia Nervosa/complicações , Bulimia/complicações , Transtornos da Personalidade/diagnóstico , Adulto , Transtorno da Personalidade Borderline/classificação , Transtorno da Personalidade Borderline/complicações , Transtorno da Personalidade Borderline/diagnóstico , Feminino , Hospitalização , Humanos , Transtornos da Personalidade/classificação , Transtornos da Personalidade/complicações , Escalas de Graduação Psiquiátrica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA