Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 263
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Appl Opt ; 56(18): 5274-5294, 2017 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29047582

RESUMO

The Cassini spacecraft orbiting Saturn carries the composite infrared spectrometer (CIRS) designed to study thermal emission from Saturn and its rings and moons. CIRS, a Fourier transform spectrometer, is an indispensable part of the payload providing unique measurements and important synergies with the other instruments. It takes full advantage of Cassini's 13-year-long mission and surpasses the capabilities of previous spectrometers on Voyager 1 and 2. The instrument, consisting of two interferometers sharing a telescope and a scan mechanism, covers over a factor of 100 in wavelength in the mid and far infrared. It is used to study temperature, composition, structure, and dynamics of the atmospheres of Jupiter, Saturn, and Titan, the rings of Saturn, and surfaces of the icy moons. CIRS has returned a large volume of scientific results, the culmination of over 30 years of instrument development, operation, data calibration, and analysis. As Cassini and CIRS reach the end of their mission in 2017, we expect that archived spectra will be used by scientists for many years to come.

3.
Redox Biol ; 60: 102599, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36640725

RESUMO

Head and neck squamous cell carcinoma (HNSCC) patients treated with high-dose cisplatin concurrently with radiotherapy (hdCis-RT) commonly suffer kidney injury leading to acute and chronic kidney disease (AKD and CKD, respectively). We conducted a retrospective analysis of renal function and kidney injury-related plasma biomarkers in a subset of HNSCC subjects receiving hdCis-RT in a double-blinded, placebo-controlled clinical trial (NCT02508389) evaluating the superoxide dismutase mimetic, avasopasem manganese (AVA), an investigational new drug. We found that 90 mg AVA treatment prevented a significant reduction in estimated glomerular filtration rate (eGFR) three months as well as six and twelve months after treatment compared to 30 mg AVA and placebo. Moreover, AVA treatment may have allowed renal repair in the first 22 days following cisplatin treatment as evidenced by an increase in epithelial growth factor (EGF), known to aid in renal recovery. An upward trend was also observed in plasma iron homeostasis proteins including total iron (Fe-blood) and iron saturation (Fe-saturation) in the 90 mg AVA group versus placebo. These data support the hypothesis that treatment with 90 mg AVA mitigates cisplatin-induced CKD by inhibiting hdCis-induced renal changes and promoting renal recovery.


Assuntos
Neoplasias de Cabeça e Pescoço , Insuficiência Renal Crônica , Humanos , Benchmarking , Cisplatino/efeitos adversos , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/metabolismo , Ferro/metabolismo , Rim/metabolismo , Insuficiência Renal Crônica/induzido quimicamente , Insuficiência Renal Crônica/tratamento farmacológico , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia
4.
Clin Genet ; 82(3): 248-55, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21801163

RESUMO

Corpus callosum abnormalities, intellectual disability, speech impairment, and autism in patients with haploinsufficiency of ARID1B. Corpus callosum abnormalities are common brain malformations with a wide clinical spectrum ranging from severe intellectual disability to normal cognitive function. The etiology is expected to be genetic in as much as 30-50% of the cases, but the underlying genetic cause remains unknown in the majority of cases. By next-generation mate-pair sequencing we mapped the chromosomal breakpoints of a patient with a de novo balanced translocation, t(1;6)(p31;q25), agenesis of corpus callosum (CC), intellectual disability, severe speech impairment, and autism. The chromosome 6 breakpoint truncated ARID1B which was also truncated in a recently published translocation patient with a similar phenotype. Quantitative polymerase chain reaction (Q-PCR) data showed that a primer set proximal to the translocation showed increased expression of ARID1B, whereas primer sets spanning or distal to the translocation showed decreased expression in the patient relative to a non-related control set. Phenotype-genotype comparison of the translocation patient to seven unpublished patients with various sized deletions encompassing ARID1B confirms that haploinsufficiency of ARID1B is associated with CC abnormalities, intellectual disability, severe speech impairment, and autism. Our findings emphasize that ARID1B is important in human brain development and function in general, and in the development of CC and in speech development in particular.


Assuntos
Anormalidades Múltiplas/genética , Agenesia do Corpo Caloso/genética , Transtorno Autístico/genética , Proteínas de Ligação a DNA/genética , Deficiência Intelectual/genética , Distúrbios da Fala/genética , Fatores de Transcrição/genética , Adulto , Pré-Escolar , Haploinsuficiência , Humanos , Masculino , Pessoa de Meia-Idade
5.
Nat Med ; 6(4): 470-3, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10742158

RESUMO

Attention-deficit/hyperactivity disorder is a highly heritable and prevalent neuropsychiatric disorder estimated to affect 6% of school-age children. Its clinical hallmarks are inattention, hyperactivity and impulsivity, which often respond substantially to treatment with methylphenidate or dextroamphetamine. Etiological theories suggest a deficit in corticostriatal circuits, particularly those components modulated by dopamine. We developed a new functional magnetic resonance imaging procedure (T2 relaxometry) to indirectly assess blood volume in the striatum (caudate and putamen) of boys 6-12 years of age in steady-state conditions. Boys with attention-deficit/hyperactivity disorder had higher T2 relaxation time measures in the putamen bilaterally than healthy control subjects. Relaxation times strongly correlated with the child's capacity to sit still and his accuracy in accomplishing a computerized attention task. Daily treatment with methylphenidate significantly changed the T2 relaxation times in the putamen of children with attention-deficit/hyperactivity disorder, although the magnitude and direction of the effect was strongly dependent on the child's unmedicated activity state. There was a similar but nonsignificant trend in the right caudate. T2 relaxation time measures in thalamus did not differ significantly between groups, and were not affected by methylphenidate. Attention-deficit/hyperactivity disorder symptoms may be closely tied to functional abnormalities in the putamen, which is mainly involved in the regulation of motor behavior.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Encéfalo/irrigação sanguínea , Gânglios/fisiopatologia , Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Estudos de Casos e Controles , Estimulantes do Sistema Nervoso Central/uso terapêutico , Criança , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Metilfenidato/uso terapêutico
6.
Environ Technol ; 31(8-9): 979-91, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20662386

RESUMO

Molecular characterization of subsurface microbial communities in the former Homestake gold mine, South Dakota, was carried out by 16S rDNA sequence analysis using a water sample and a weathered soil-like sample. Geochemical analyses indicated that both samples were high in sulphur, rich in nitrogen and salt, but with significantly different metal concentrations. Microbial diversity comparisons unexpectedly revealed three distinct operational taxonomic units (OTUs) belonging to the archaeal phylum Thaumarchaeota, typically identified from marine environments, and one OTU belonging to a potentially novel phylum that fell sister to Thaumarchaeota. To our knowledge this is only the second report of Thaumarchaeota in a terrestrial environment. The majority of the clones from Archaea sequence libraries fell into two closely related OTUs and were grouped most closely to an ammonia-oxidizing, carbon-fixing and halophilic thaumarchaeote genus, Nitrosopumilus. The two samples showed neither Euryarchaeota nor Crenarchaeota members that have often been identified from other subsurface terrestrial ecosystems. Bacteria OTUs containing the highest percentage of sequences were related to sulphur-oxidizing bacteria of the orders Chromatiales and Thiotrichales. Community members of Bacteria from individual Homestake ecosystems were heterogeneous and distinctive to each community, with unique phylotypes identified within each sample.


Assuntos
Archaea/isolamento & purificação , Bactérias/isolamento & purificação , Sedimentos Geológicos/microbiologia , Filogenia , Microbiologia do Solo , Microbiologia da Água , Archaea/genética , Bactérias/genética , Sequência de Bases , DNA Arqueal/química , DNA Arqueal/genética , DNA Bacteriano/química , DNA Bacteriano/genética , Mineração , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genética , Alinhamento de Sequência , Análise de Sequência de DNA , South Dakota
7.
Science ; 204(4391): 375-80, 1979 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-220706

RESUMO

Space-filling models of yeast hexokinase, adenylate kinase, and phosphoglycerate kinase drawn by computer clearly portray the bilobal character of these phosphoryl transfer enzymes, and the deep cleft which is formed between the lobes. A dramatic conformational change occurs in hexokinase as glucose binds to the bottom of the cleft, which causes the two lobes of hexokinase to come together. A substrate-induced closing of the active site cleft is postulated to occur in other kinases as well. This change may provide a mechanism by which some of these enzymes reduce their inherent adenosine triphosphatase activity and could be a general requirement of the kinase reaction.


Assuntos
Fosfotransferases , Adenilato Quinase , Sítios de Ligação , Catálise , Hexoquinase , Modelos Moleculares , Fosfoglicerato Quinase , Conformação Proteica , Saccharomyces cerevisiae/enzimologia , Relação Estrutura-Atividade
8.
Tob Control ; 16 Suppl 1: i81-6, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18048638

RESUMO

Telephone based tobacco cessation services, or quitlines, have become central components of many comprehensive tobacco control programmes. This paper provides an overview of their history, noting milestones in the growth of quitlines. Key factors in their worldwide adoption were solid evidence from clinical trials with large community samples and strong backing from public health officials. Quitlines are now available throughout most of North America, Europe, Australia and in many other locations around the world. The paper also offers several recommendations for future directions in quitline practice and research. Benchmarks should be established for key areas of quitline implementation, such as accessibility, quality and cost efficiency. Advances in pharmacotherapy, telephony and web based applications should be investigated for opportunities to expand service offerings. Research and development are needed to determine how best to serve a diverse clientele in the most cost effective manner. Funding should be expanded and diversified to enable quitlines to serve much larger numbers of users. Healthcare providers should be targeted for quitline promotion, to engage them in a broad effort to increase the number of patients receiving cessation messages from clinicians. The goal of quitline promotion should expand to include an increase in unaided quit attempts in the population. Early research findings were quickly adopted in quitline practice, and future research to answer questions that have arisen through the implementation of quitlines will probably also find quick adoption.


Assuntos
Linhas Diretas/tendências , Abandono do Uso de Tabaco/métodos , Protocolos Clínicos , Aconselhamento/organização & administração , Aconselhamento/tendências , Atenção à Saúde/tendências , Medicina Baseada em Evidências , Linhas Diretas/organização & administração , Humanos
9.
Avian Dis ; 50(3): 463-6, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17039853

RESUMO

A flock of approximately 15,000 ring-necked pheasants (Phasianus colchicus) was evaluated for a sudden increase in mortality and acute neurological signs after having been previously diagnosed 3 wk earlier with a chronic respiratory disease of undetermined etiology. Approximately 25 live birds were displaying neurological signs including circling, ataxia, and obtunded behavior and 50 birds were dead. Three birds with neurological signs were submitted for evaluation. Extensive subcutaneous hemorrhage over the head and penetrating puncture wounds through the skull and into the brain were found. Trauma from a wild predatory mammal, most likely the long-tailed weasel (Mustela frenata) that had invaded the pheasant house and expressed surplus killing behavior was determined to be the cause of the acute neurological signs and mortality. The relationship of the chronic respiratory disease to the predation episode was not determined but it is possible that pheasants with severe respiratory disease may have had increased susceptibility to predation.


Assuntos
Doenças das Aves/etiologia , Doenças das Aves/fisiopatologia , Galliformes/lesões , Mustelidae/fisiologia , Doenças do Sistema Nervoso/veterinária , Comportamento Predatório/fisiologia , Animais , Doenças das Aves/diagnóstico , Feminino , Masculino , Doenças do Sistema Nervoso/diagnóstico , Doenças do Sistema Nervoso/etiologia , Pele/lesões , Crânio/lesões
10.
Behav Brain Res ; 308: 83-93, 2016 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-27060720

RESUMO

Early life stress in rodents is associated with increased amygdala volume in adulthood. In humans, the amygdala develops rapidly during the first two years of life. Thus, disturbed care during this period may be particularly important to amygdala development. In the context of a 30-year longitudinal study of impoverished, highly stressed families, we assessed whether disorganization of the attachment relationship in infancy was related to amygdala volume in adulthood. Amygdala volumes were assessed among 18 low-income young adults (8M/10F, 29.33±0.49years) first observed in infancy (8.5±5.6months) and followed longitudinally to age 29. In infancy (18.58±1.02mos), both disorganized infant attachment behavior and disrupted maternal communication were assessed in the standard Strange Situation Procedure (SSP). Increased left amygdala volume in adulthood was associated with both maternal and infant components of disorganized attachment interactions at 18 months of age (overall r=0.679, p<0.004). Later stressors, including childhood maltreatment and attachment disturbance in adolescence, were not significantly related to left amygdala volume. Left amygdala volume was further associated with dissociation and limbic irritability in adulthood. Finally, left amygdala volume mediated the prediction from attachment disturbance in infancy to limbic irritability in adulthood. Results point to the likely importance of quality of early care for amygdala development in human children as well as in rodents. The long-term prediction found here suggests that the first two years of life may be an early sensitive period for amygdala development during which clinical intervention could have particularly important consequences for later child outcomes.


Assuntos
Tonsila do Cerebelo/crescimento & desenvolvimento , Anomia (Social) , Apego ao Objeto , Adolescente , Adulto , Tonsila do Cerebelo/diagnóstico por imagem , Criança , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Lactente , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Fatores de Risco , Adulto Jovem
11.
Trends Pharmacol Sci ; 18(10): 387-92, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9357323

RESUMO

Increasing evidence for receptors for uracil nucleotides has focused interest on specific signalling mechanisms involving UTP and UDP. At least three metabotropic P2 receptors are stimulated by uracil nucleotides with equal or greater potency than by adenine nucleotides, and there might be ionotropic receptors as well. Regulation of uridine and uracil nucleotide levels is important when considering the receptor-mediated effects of these compounds. Cells can synthesize uracil nucleotides de novo or by salvage of uridine. UTP made from salvage might be preferentially used for RNA synthesis in the nucleus, while UTP synthesized de novo seems to be used for UDP-sugar and CDP-phospholipid production. UTP from both pathways can enter a free UTP pool, from which UTP can be released from cells. UTP and UDP can stimulate pyrimidinoceptors, but metabolism by ecto-nucleotidases limits their effects. Alternatively, UTP might be a substrate for ecto-protein kinases, and this could contribute to its extracellular regulation. Cells can reclaim uridine, using nucleoside transport processes, following dephosphorylation of UTP, UDP and UMP. In this article Christopher Anderson and Fiona Parkinson discuss how understanding the processes that regulate uridine and uracil nucleotide concentrations will enhance our ability to manipulate UTP/UDP signalling pathways for pharmacological effect.


Assuntos
Transdução de Sinais/fisiologia , Nucleotídeos de Uracila/fisiologia , Difosfato de Uridina/fisiologia , Uridina Trifosfato/fisiologia , Animais , Humanos
12.
Mitochondrion ; 5(1): 1-13, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16060289

RESUMO

The adenine nucleotide translocase (ANT) is a key component in maintaining cellular energy homeostasis, and has also been implicated in formation of the mitochondrial permeability transition pore. Human ANT-3 was cloned from a human heart cDNA library and expressed as a histidine-tagged fusion protein in the mitochondria of the Trichoplusia ni. cell line. Overexpression resulted in a concomitant decrease in the endogenous ANT content, allowing for the characterization of binding of known ANT ligands to the human protein. Binding affinities for bongkrekic acid (BKA), ADP, and atractyloside (ATR) were measured in mitochondria from the human ANT-3 expressing cell line, and compared to similar preparations from bovine heart mitochondria by use of a novel radioiodinated derivative of ATR. Binding to ANT-3 by the high affinity inhibitors BKA and ATR, as well as the lower affinity natural ligand ADP, was similar to that measured in bovine heart mitochondria, and to that previously reported for mammalian heart mitochondria. Characterizations such as these of human ANT isoforms may lead to drug development for enhanced mitochondrial function and cellular viability.


Assuntos
Translocador 3 do Nucleotídeo Adenina/genética , Translocador 3 do Nucleotídeo Adenina/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Difosfato de Adenosina/metabolismo , Animais , Atractilosídeo/análogos & derivados , Atractilosídeo/química , Atractilosídeo/metabolismo , Ácido Bongcréquico/metabolismo , Bovinos , Linhagem Celular , Metabolismo Energético , Expressão Gênica , Humanos , Técnicas In Vitro , Radioisótopos do Iodo , Cinética , Ligantes , Mitocôndrias Cardíacas/metabolismo , Mariposas , Ligação Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
13.
Arch Gen Psychiatry ; 34(6): 697-702, 1977 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-194547

RESUMO

Although there is considerable evidence that family variables and interaction patterns affect the duration of hospitalization and frequency of readmission of psychiatric patients, it is rare to find inpatient facilities having psychotherapeutic programs that systematically stress family interventions. This article discusses the difficulties encountered by both families and staff as they cope with the issues of hospitalization, suggests a structured, patient-oriented family approach, and recommends some specific techniques for short-term work with families of severely disturbed inpatients.


Assuntos
Terapia Familiar/métodos , Hospitalização , Transtornos Mentais/terapia , Doença Aguda , Assistência ao Convalescente , Atitude do Pessoal de Saúde , Atitude Frente a Saúde , Humanos , Planejamento de Assistência ao Paciente , Relações Profissional-Família , Unidade Hospitalar de Psiquiatria
14.
Arch Gen Psychiatry ; 43(7): 633-42, 1986 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2872870

RESUMO

Relapse rates averaging 41% in the first year after discharge among schizophrenic patients receiving maintenance neuroleptic treatment led to the development of two disorder-relevant treatments: a patient-centered behavioral treatment and a psychoeducational family treatment. Following hospital admission, 103 patients residing in high expressed emotion (EE) households who met Research Diagnostic Criteria for schizophrenia or schizoaffective disorder were randomly assigned to a two-year aftercare study of family treatment and medication, social skills training and medication, their combination, or a drug-treated condition. First-year relapse rates among those exposed to treatment demonstrate a main effect for family treatment (19%), a main effect for social skills training (20%), and an additive effect for the combined conditions (0%) relative to controls (41%). Effects are explained, in part, by the absence of relapse in any household that changed from high to low EE. Only the combination of treatment sustains a remission in households that remain high in EE. Continuing study, however, suggests a delay of relapse rather than prevention.


Assuntos
Assistência ao Convalescente , Antipsicóticos/uso terapêutico , Terapia Comportamental , Terapia Familiar , Esquizofrenia/terapia , Adulto , Atitude Frente a Saúde , Ensaios Clínicos como Assunto , Emoções , Família , Feminino , Seguimentos , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Transtornos Psicóticos/tratamento farmacológico , Transtornos Psicóticos/psicologia , Transtornos Psicóticos/terapia , Recidiva , Esquizofrenia/tratamento farmacológico , Psicologia do Esquizofrênico , Ajustamento Social
15.
Arch Gen Psychiatry ; 48(4): 340-7, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1672589

RESUMO

We demonstrated earlier that a novel family psychoeducational approach and an individual social skills training approach designed for patients living in high-expressed emotion households each reduced schizophrenic relapse by one-half when compared with medication controls in the 1st year after hospital discharge. The combination of treatments resulted in no relapse. Results have now been obtained after 2 years of continuous treatment. By 24 months, a persistent and significant effect of family intervention on forestalling relapse was observed, but the effect of social skills training was lost late in the 2nd year. There was no additive effect on relapse that accrued to the combination of treatments. Beyond 2 years, however, the effect of family intervention was likely compromised as well. Treatment effects on the adjustment of survivors were circumscribed, due, in part, to study design characteristics. Effects generally favored the social skills-alone condition at 1 year and the family condition or combined family/social skills condition at 2 years.


Assuntos
Assistência ao Convalescente/métodos , Antipsicóticos/uso terapêutico , Terapia Comportamental , Terapia Familiar , Esquizofrenia/prevenção & controle , Ajustamento Social , Adulto , Assistência Ambulatorial , Atitude Frente a Saúde , Terapia Combinada , Emoções , Emprego , Família/psicologia , Feminino , Seguimentos , Humanos , Masculino , Inventário de Personalidade , Escalas de Graduação Psiquiátrica , Recidiva , Projetos de Pesquisa , Esquizofrenia/diagnóstico , Psicologia do Esquizofrênico
16.
Mol Endocrinol ; 14(12): 1976-85, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11117528

RESUMO

Unliganded thyroid hormone receptors (TRs) repress transcription through recruitment of corepressors, including nuclear receptor corepressor (N-CoR). We find that N-CoR contains three interaction domains (IDs) that bind to TR, rather than the previously reported two. The hitherto unrecognized ID (ID3) serves as a fully functional TR binding site, both in vivo and in vitro, and may be the most important for TR binding. Each ID motif contains a conserved hydrophobic core (I/LXXII) that resembles the hydrophobic core of nuclear receptor boxes (LXXLL), which mediates p160 coactivator binding to liganded nuclear receptors. Although the integrity of the I/LXXII motif is required for ID function, substitution of ID isoleucines with leucines did not allow ID peptides to bind to liganded TR, and substitution of NR box leucines with isoleucines did not allow NR box peptides to bind unliganded TR. This indicates that the binding preferences of N-CoR for unliganded TR and p160s for liganded TR are not dictated solely by the identity of conserved hydrophobic residues within their TR binding motifs. Examination of sequence conservation between IDs, and mutational analysis of individual IDs, suggests that they are comprised of the central hydrophobic core and distinct adjacent sequences that may make unique contacts with the TR surface. Accordingly, a hybrid peptide that contains distinct adjacent sequences from ID3 and ID1 shows enhanced binding to TR.


Assuntos
Isoleucina/metabolismo , Proteínas Nucleares/genética , Receptores dos Hormônios Tireóideos/metabolismo , Proteínas Repressoras/genética , Motivos de Aminoácidos , Animais , Células Cultivadas , Embrião de Galinha , Substâncias Macromoleculares , Mutação , Proteínas Nucleares/metabolismo , Correpressor 1 de Receptor Nuclear , Oligopeptídeos/metabolismo , Estrutura Terciária de Proteína , Proteínas Repressoras/metabolismo , Transcrição Gênica , Técnicas do Sistema de Duplo-Híbrido
17.
Mol Endocrinol ; 12(2): 302-13, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9482670

RESUMO

The activity of the AF-2 transcriptional activation function of nuclear receptors (NR) is mediated by the partially homologous transcriptional coactivators, glucocorticoid receptor interacting protein 1 (GRIP1)/transcriptional intermediary factor 2 (TIF2) and steroid receptor coactivator 1 (SRC-1). GRIP1 and SRC-1 bound nine different NRs and exhibited similar, but not identical, NR binding preferences. The most striking difference was seen with the androgen receptor, which bound well to GRIP1 but poorly to SRC-1. GRIP1 and SRC-1 contain three copies of the NR binding motif LXXLL (called an NR Box) in their central regions. Mutation of both NR Box II and NR Box III in GRIP1 almost completely eliminated functional and binding interactions with NRs, indicating that these two sites are crucial for most of GRIP1's NR binding activity. Interactions of GRIP1 with the estrogen receptor were more strongly affected by mutations in NR Box II, whereas interactions with the androgen receptor and glucocorticoid receptor were more strongly affected by NR Box III mutations. One isoform of SRC-1 has an additional NR Box (NR Box IV) at its extreme C terminus with an NR-binding preference somewhat different from that of the central NR-binding domain of SRC-1. GRIP1 has no NR Box in its C-terminal region and therefore no C-terminal NR-binding function. In summary, GRIP1 and SRC-1 have overlapping NR-binding preferences, but specific NRs display both coactivator and NR Box preferences that may contribute to the specificity of hormonal responses.


Assuntos
Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores de Esteroides/metabolismo , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Sítios de Ligação/genética , Células HeLa , Histona Acetiltransferases , Humanos , Dados de Sequência Molecular , Coativador 1 de Receptor Nuclear , Coativador 2 de Receptor Nuclear , Receptores Citoplasmáticos e Nucleares/química , Receptores dos Hormônios Tireóideos/metabolismo , Saccharomyces cerevisiae , Fatores de Transcrição/química
18.
Diabetes Care ; 23(6): 775-8, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10840995

RESUMO

OBJECTIVE: To determine the diagnostic performance characteristics of HNF1A genotyping for diabetes and impaired glucose tolerance (IGT) in Canadian Oji-Cree Indians. RESEARCH DESIGN AND METHODS: We studied all Oji-Cree subjects > or = 50 years of age (96 subjects) who had participated in a community-wide prevalence survey for type 2 diabetes. Subjects were classified either as having "disease," which included type 2 diabetes and IGT, or not. All subjects were genotyped for the HNF1A G319S mutation. RESULTS: The prevalence of disease in this group was 65.7%, of whom 71.4% had type 2 diabetes. For a carrier of HNF1A S319, the specificity, sensitivity, and positive and negative predictive values were 97.0, 30.1, 95.0, and 42.1%, respectively. When the pretest disease prevalence was accounted for, the probability of disease after a positive test was 97.2%, and the probability of disease after a negative test was 42.2%. The values were very similar for the subgroup of subjects with type 2 diabetes alone. CONCLUSIONS: The HNF1A genotype appears to be the most specific genetic test yet reported for the prediction of a common multifactorial disease by applying present-day standards of clinical epidemiology in molecular genetics. A positive test result had particular diagnostic value in the Oji-Cree: a subject with HNF1A S319 was virtually certain of having diabetes or IGT by 50 years of age. In contrast, a subject without HNF1A S319 had a reduced risk compared with the age-specific prevalence but was not totally risk-free. Because HNF1A S319 was not the only predisposing factor for diabetes in the Oji-Cree, subjects without HNF1A S319 were still at some risk for diabetes or IGT.


Assuntos
Proteínas de Ligação a DNA , Diabetes Mellitus/genética , Intolerância à Glucose/genética , Indígenas Norte-Americanos/genética , Fatores de Transcrição/genética , Canadá/epidemiologia , Estudos Transversais , Diabetes Mellitus/epidemiologia , Genótipo , Intolerância à Glucose/epidemiologia , Fator 1 Nuclear de Hepatócito , Fator 1-alfa Nuclear de Hepatócito , Fator 1-beta Nuclear de Hepatócito , Humanos , Pessoa de Meia-Idade , Proteínas Nucleares/genética , Prevalência
19.
Physiol Genomics ; 3(1): 39-44, 2000 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-11015599

RESUMO

We previously showed that a rare mutation in LMNA, which encodes lamins A and C, underlies autosomal dominant Dunnigan-type familial partial lipodystrophy (FPLD). Because FPLD is an extreme example of genetically disturbed adipocyte differentiation, it is possible that common variation in LMNA is associated with obesity-related phenotypes. We therefore analyzed the relationships between the common LMNA 1908T/C single nucleotide polymorphism (SNP) and plasma leptin and anthropometric indices in 306 nondiabetic Canadian Oji-Cree. We found that subjects with the LMNA 1908T/1908T genotype had significantly higher plasma leptin than the subjects with either the 1908C/1908T or 1908C/1908C genotypes, after adjustment for age and sex. Physical indices of obesity, such as body mass index, percent body fat, and ratio of waist-to-hip circumference, were also higher among Oji-Cree subjects with the LMNA 1908T/1908T genotype than the subjects with either the 1908C/1908T or 1908C/1908C genotypes. The results suggest that common genetic variation in LMNA may be an important determinant of plasma leptin and obesity-related quantitative traits.


Assuntos
Variação Genética , Indígenas Norte-Americanos/genética , Leptina/sangue , Proteínas Nucleares/genética , Obesidade/etnologia , Obesidade/genética , Adulto , Alelos , Povo Asiático/genética , Composição Corporal/genética , Constituição Corporal/genética , Índice de Massa Corporal , Canadá/epidemiologia , Feminino , Frequência do Gene , Testes Genéticos , Genótipo , Humanos , Laminas , Leptina/genética , Masculino , Análise Multivariada , Obesidade/sangue , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Característica Quantitativa Herdável
20.
Endocrinology ; 138(7): 2900-8, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9202234

RESUMO

Estrogens and glucocorticoids often act in opposition to regulate physiological responses. We investigated whether this might reflect the opposing actions of hormone-bound receptors on target genes regulated by the AP-1 response element. We performed a series of transfection experiments in which transcriptional activation, mediated by the AP-1 response element, was reflected in reporter gene activity. As previously described, we found that estrogens stimulate, whereas the glucocorticoid dexamethasone (Dex) inhibits, transcription through a model promoter from the collagenase gene (-73 to +63). This promoter bears a consensus AP-1 response element. When HeLa cells were treated with both estradiol and Dex, the steroids counteracted each other's transcriptional effects. The amount of transfected estrogen and glucocorticoid receptors (ER and GR) determined the extent to which Dex blunted estrogen stimulation or estrogen prevented Dex inhibition. The ER/GR interaction was observed both in the presence of estradiol and tamoxifen, which has previously been shown to have estrogen-like action at an AP-1 response element. The AP-1 family member c-Jun enhanced Dex inhibition and estradiol stimulation of transcriptional activation. c-Fos potentiated the effect of cotransfected c-Jun on estradiol stimulation but not Dex inhibition. The pattern of steroid responses was retained in the presence of the c-Jun activator phorbol 12-myristate 13-acetate. However, estradiol stimulation was lost in the presence of the c-Jun activator tumor necrosis factor-alpha. The ER/GR/AP-1 response element interaction was present, not only in a cell line originally derived from a uterine cervical adenocarcinoma (HeLa), but also in a cell line derived from the hypothalamus (GT1-1). Lastly, both progesterone receptor types A and B also interacted with the ER at the AP-1 site. These data indicate that opposing steroid influences can be mediated at the level of transcription through the AP-1 site and suggest that the integration of hormone action at this response element may underlie some of the opposing actions of estrogens and glucocorticoids or progestins on physiological responses.


Assuntos
Receptores de Estrogênio/genética , Receptores de Glucocorticoides/genética , Fator de Transcrição AP-1/genética , Transcrição Gênica , Dexametasona/farmacologia , Antagonistas de Estrogênios/farmacologia , Glucocorticoides/farmacologia , Células HeLa , Humanos , Hipotálamo/metabolismo , Progesterona/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Proteínas Proto-Oncogênicas c-jun/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Glucocorticoides/metabolismo , Tamoxifeno/farmacologia , Fator de Transcrição AP-1/metabolismo , Transfecção
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA