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1.
J Viral Hepat ; 25(11): 1236-1243, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29757491

RESUMO

Hepatitis C (HCV) is a viral infection that if left untreated can severely damage the liver. Project INSPIRE was a 3 year HCV care coordination programme in New York City (NYC) that aimed to address barriers to treatment initiation and cure by providing patients with supportive services and health promotion. We examined whether enrolment in Project INSPIRE was associated with differences in HCV treatment and cure compared with a demographically similar group not enrolled in the programme. INSPIRE participants in 2015 were matched with a cohort of HCV-infected persons identified in the NYC surveillance registry, using full optimal matching on propensity scores and stratified by INSPIRE enrolment status. Conditional logistic regression was used to assess group differences in the two treatment outcomes. Two follow-up sensitivity analyses using individual pair-matched sets and the full unadjusted cohort were also conducted. Treatment was initiated by 72% (790/1130) of INSPIRE participants and 36% (11 960/32 819) of study-eligible controls. Among initiators, 65% (514/790) of INSPIRE participants compared with 47% (5641/11 960) of controls achieved cure. In the matched analysis, enrolment in INSPIRE increased the odds of treatment initiation (OR: 5.25, 95% CI: 4.47-6.17) and cure (OR: 2.52, 95% CI: 2.00-3.16). Results from the sensitivity analyses showed agreement with the results from the full optimal match. Participation in the HCV care coordination programme significantly increased the probability of treatment initiation and cure, demonstrating that care coordination for HCV-infected individuals improves treatment outcomes.


Assuntos
Antivirais/uso terapêutico , Assistência Integral à Saúde/estatística & dados numéricos , Hepatite C/tratamento farmacológico , Estudos de Coortes , Feminino , Hepacivirus/efeitos dos fármacos , Hepatite C/diagnóstico , Hepatite C/epidemiologia , Hepatite C/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Cidade de Nova Iorque/epidemiologia , Avaliação de Programas e Projetos de Saúde , Pontuação de Propensão , Resultado do Tratamento , Carga Viral/efeitos dos fármacos
2.
J Clin Microbiol ; 54(1): 99-105, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26511737

RESUMO

Here we compared the results of PCR/pyrosequencing to those of culture for detecting bacteria directly from blood. DNA was extracted from 1,130 blood samples from 913 patients suspected of bacteremia (enrollment criteria were physician-ordered blood culture and complete blood count [CBC]), and 102 controls (healthy blood donors). Real-time PCR assays for beta-globin and Universal 16S rRNA gene targets were performed on all 1,232 extracts. Specimens identified by Universal 16S rRNA gene PCR/pyrosequencing as containing staphylococci, streptococci, or enteric Gram-negative rods had target-specific PCR/pyrosequencing performed. Amplifiable beta-globin (melting temperature [Tm], 87.2°C ± 0.2°C) occurred in 99.1% (1,120/1,130) of patient extracts and 100% (102/102) of controls. Concordance between PCR/pyrosequencing and culture was 96.9% (1,085/1,120) for Universal 16S rRNA gene targets, with positivity rates of 9.4% (105/1,120) and 11.3% (126/1,120), respectively. Bacteria cultured included staphylococci (59/126, 46.8%), Gram-negative rods (34/126, 27%), streptococci (32/126, 25.4%), and a Gram-positive rod (1/126, 0.8%). All controls screened negative by PCR/pyrosequencing. Clinical performance characteristics (95% confidence interval [CI]) for Universal 16S rRNA gene PCR/pyrosequencing included sensitivity of 77.8% (69.5 to 84.7), specificity of 99.3% (98.6 to 99.7), positive predictive value (PPV) of 93.3% (86.8 to 97.3), and negative predictive value (NPV) of 97.2% (96.0 to 98.2). Bacteria were accurately identified in 77.8% (98/126) of culture-confirmed sepsis samples with Universal 16S PCR/pyrosequencing and in 76.4% (96/126) with follow-up target-specific PCR/pyrosequencing. The initial PCR/pyrosequencing took ∼5.5 h to complete or ∼7.5 h when including target-specific PCR/pyrosequencing compared to 27.9 ± 13.6 h for Gram stain or 81.6 ± 24.0 h for phenotypic identification. In summary, this molecular approach detected the causative bacteria in over three-quarters of all culture-confirmed cases of bacteremia directly from blood in significantly less time than standard culture but cannot be used to rule out infection.


Assuntos
Bacteriemia/diagnóstico , Bactérias/isolamento & purificação , Técnicas Bacteriológicas/métodos , Programas de Rastreamento/métodos , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Análise de Sequência de DNA/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bactérias/classificação , DNA Bacteriano/genética , DNA Ribossômico/genética , Serviço Hospitalar de Emergência , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , RNA Ribossômico 16S/genética , Sensibilidade e Especificidade , Adulto Jovem
4.
Scand J Med Sci Sports ; 22(5): e108-14, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22852581

RESUMO

The objective of this study was to evaluate the effects of genistein and moderate intensity exercise on Achilles tendon collagen and cross-linking in intact and ovariectomized (OVX) female Sprague-Dawley rats. Rats were separated into eight groups (n = 9/group): intact or OVX, treadmill exercised or sedentary, genistein-treated (300 mg/kg/day) or vehicle. After 6 weeks, tendons were assayed for the collagen-specific amino acid hydroxyproline and hydroxylyslpyridinoline (HP). Collagen content was not influenced by exercise (P = 0.40) but was lower (P < 0.001) in OVX-vehicle rats compared with intact vehicle rats (OVX: 894 ± 35 µg collagen/mg dry weight; intact: 1185 ± 72 µg collagen/mg dry weight). In contrast, collagen content in OVX rats treated with genistein was greater (P = 0.010, 1198 ± 121 µg collagen/mg dry weight) when compared with untreated rats and was not different from intact rats (P = 0.89). HP content was lower in OVX genistein-treated rats when compared with intact genistein-treated rats, but only within the sedentary animals (P = 0.05, intact-treated: 232 ± 39 mmol/mol collagen; OVX-treated: 144 ± 21 mmol/mol collagen). Our findings suggest that ovariectomy leads to a reduction in tendon collagen, which is prevented by genistein. HP content, however, may not have increased in proportion to the addition of collagen. Genistein may be useful for improving tendon collagen content in conditions of estrogen deficiency.


Assuntos
Tendão do Calcâneo/metabolismo , Colágeno/metabolismo , Genisteína/farmacologia , Ovariectomia , Condicionamento Físico Animal/fisiologia , Fitoestrógenos/farmacologia , Tendão do Calcâneo/efeitos dos fármacos , Animais , Colágeno/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Ratos , Ratos Sprague-Dawley , Estatística como Assunto
5.
Trends Cell Biol ; 9(8): 312-8, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10407410

RESUMO

The nuclear pore complex (NPC) connects the cytoplasm and nucleus through the nuclear envelope and serves as the pipeline for moving material between the two compartments. Macromolecules that move through the NPC range in size from the very small (for example, ions and ATP) to the very large (for example, ribonucleoprotein particle complexes). Unlike translocation across other organelle membranes, proteins do not have to be unfolded to be transported through the NPC, and the NPC also routinely transports large, multicomponent substrates in both directions. This review focuses on current understanding of the different mechanisms by which macromolecules move across the NPC.


Assuntos
Membrana Nuclear/fisiologia , Animais , Transporte Biológico , Difusão , Humanos , Microscopia Eletrônica , Modelos Biológicos , Membrana Nuclear/ultraestrutura , Transdução de Sinais
6.
J Cell Biol ; 151(2): 321-32, 2000 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-11038179

RESUMO

p10/NTF2 is a nuclear transport carrier that mediates the uptake of cytoplasmic RanGDP into the nucleus. We constructed a point mutant of p10, D23A, that exhibited unexpected behavior both in digitonin-permeabilized and microinjected mammalian cells. D23A p10 was markedly more efficient than wild-type (wt) p10 at supporting Ran import, but simultaneously acted as a dominant-negative inhibitor of classical nuclear localization sequence (cNLS)-mediated nuclear import supported by karyopherins (Kaps) alpha and beta1. Binding studies indicated that these two nuclear transport carriers of different classes, p10 and Kap-beta1, compete for identical and/or overlapping binding sites at the nuclear pore complex (NPC) and that D23A p10 has an increased affinity relative to wt p10 and Kap-beta1 for these shared binding sites. Because of this increased affinity, D23A p10 is able to import its own cargo (RanGDP) more efficiently than wt p10, but Kap-beta1 can no longer compete efficiently for shared NPC docking sites, thus the import of cNLS cargo is inhibited. The competition of different nuclear carriers for shared NPC docking sites observed here predicts a dynamic equilibrium between multiple nuclear transport pathways inside the cell that could be easily shifted by a transient modification of one of the carriers.


Assuntos
Transporte Ativo do Núcleo Celular , Proteínas de Transporte/genética , Poro Nuclear/metabolismo , Proteínas Nucleares/genética , Proteínas de Transporte Nucleocitoplasmático , Proteína ran de Ligação ao GTP/metabolismo , Sítios de Ligação , Proteínas de Transporte/metabolismo , Guanosina Difosfato/metabolismo , Sinais de Localização Nuclear/antagonistas & inibidores , Proteínas Nucleares/metabolismo , Fragmentos de Peptídeos/metabolismo , Mutação Puntual , Ligação Proteica , Proteínas de Saccharomyces cerevisiae , beta Carioferinas
7.
J Cell Biol ; 114(5): 881-91, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1908471

RESUMO

Receptor-mediated endocytosis begins with the binding of ligand to receptors in clathrin-coated pits followed by the budding of the pits away from the membrane. We have successfully reconstituted this sequence in vitro. Highly purified plasma membranes labeled with gold were obtained by incubating cells in the presence of anti-LDL receptor IgG-gold at 4 degrees C, attaching the labeled cells to a poly-L-lysine-coated substratum at 4 degrees C and then gently sonicating them to remove everything except the adherent membrane. Initially the gold label was clustered over flat, clathrin-coated pits. After these membranes were warmed to 37 degrees C for 5-10 min in the presence of buffer that contained cytosol extract, Ca2+, and ATP, the coated pits rounded up and budded from the membrane, leaving behind a membrane that was devoid of LDL gold. Simultaneous with the loss of the ligand, the clathrin triskelion and the AP-2 subunits of the coated pit were also lost. These results suggest that the budding of a coated pit to form a coated vesicle occurs in two steps: (a) the spontaneous rounding of the flat lattice into a highly invaginated coated pit at 37 degrees C; (b) the ATP, 150 microM Ca2+, and cytosolic factors(s) dependent fusion of the adjoining membrane segments at the neck of the invaginated pit.


Assuntos
Clatrina/metabolismo , Invaginações Revestidas da Membrana Celular/metabolismo , Endocitose , Receptores de LDL/metabolismo , Nucleotídeos de Adenina/farmacologia , Cálcio/farmacologia , Sistema Livre de Células , Invaginações Revestidas da Membrana Celular/ultraestrutura , Citosol/metabolismo , Etilmaleimida/farmacologia , Nucleotídeos de Guanina/farmacologia , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Agregação de Receptores , Receptores de LDL/imunologia
8.
J Cell Biol ; 108(5): 1615-24, 1989 May.
Artigo em Inglês | MEDLINE | ID: mdl-2565904

RESUMO

Isolated human fibroblast plasma membranes that were attached by their extracellular surface to a solid substratum contained numerous clathrin coated pits that could be removed with a high pH buffer (Moore, M.S., D.T. Mahaffey, F.M. Brodsky, and R.G.W. Anderson. 1987. Science [Wash. DC]. 236:558-563). When these membranes were incubated with coat proteins extracted from purified bovine coated vesicles, new coated pits formed that were indistinguishable from native coated pits. Assembly was dependent on the concentration of coat protein with half maximal assembly occurring at 7 micrograms/ml. Assembly was only slightly affected by the presence of divalent cations. Whereas normal appearing lattices formed in a low ionic strength buffer, when assembly was carried out in a low pH buffer, few coated pits were evident but numerous small clathrin cages decorated the membrane. Coated pits did not form randomly on the surface; instead, they assembled at differentiated regions of membrane that could be distinguished in carbon/platinum replicas of frozen and etched membranes by the presence of numerous particles clustered into patches the size and shape of a coated pit.


Assuntos
Clatrina/metabolismo , Invaginações Revestidas da Membrana Celular/ultraestrutura , Endossomos/ultraestrutura , Proteínas de Membrana/metabolismo , Membrana Celular/ultraestrutura , Células Cultivadas , Clatrina/isolamento & purificação , Invaginações Revestidas da Membrana Celular/metabolismo , Fibroblastos/metabolismo , Técnica de Congelamento e Réplica , Humanos , Cinética , Proteínas de Membrana/isolamento & purificação , Microscopia Eletrônica , Peso Molecular , Pele/metabolismo
9.
Science ; 236(4801): 558-63, 1987 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-2883727

RESUMO

During receptor-mediated endocytosis, coated pits invaginate to form coated vesicles, clathrin and associated proteins dissociate from the vesicle membrane, and these proteins form new coated pits at the cell surface. As a means of elucidating molecular mechanisms that govern the function of coated pits, the assembly phase of this cycle was reconstituted by incubating purified membranes that were treated to remove endogenous coated pits with cytoplasm extracted from cultured cells. The in vitro assembly of coated pits on these membranes satisfactorily mimics many features of coated pit formation in the intact cell. These studies indicate that: the membranes contain a limited number of coated pit assembly sites that bind clathrin with high affinity; the half-time for assembly is 5 minutes both at 4 degrees C and 37 degrees C; during assembly, proteins with molecular sizes of 180, 110, and 36 kilodaltons are recruited to the plasma membrane; and assembly is not dependent on adenosine triphosphate, but this nucleotide triggers a temperature-dependent loss of coated pits that are assembled in the absence of adenosine triphosphate.


Assuntos
Membrana Celular/ultraestrutura , Clatrina/metabolismo , Invaginações Revestidas da Membrana Celular/fisiologia , Endossomos/fisiologia , Trifosfato de Adenosina/farmacologia , Membrana Celular/metabolismo , Invaginações Revestidas da Membrana Celular/efeitos dos fármacos , Invaginações Revestidas da Membrana Celular/ultraestrutura , Endocitose , Humanos , Cinética , Proteínas de Membrana/metabolismo , Microscopia Eletrônica , Peso Molecular , Temperatura
10.
Science ; 291(5504): 653-6, 2001 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-11229403

RESUMO

The guanosine triphosphatase Ran stimulates assembly of microtubule asters and spindles in mitotic Xenopus egg extracts. A carboxyl-terminal region of the nuclear-mitotic apparatus protein (NuMA), a nuclear protein required for organizing mitotic spindle poles, mimics Ran's ability to induce asters. This NuMA fragment also specifically interacted with the nuclear transport factor, importin-beta. We show that importin-beta is an inhibitor of microtubule aster assembly in Xenopus egg extracts and that Ran regulates the interaction between importin-beta and NuMA. Importin-beta therefore links NuMA to regulation by Ran. This suggests that similar mechanisms regulate nuclear import during interphase and spindle assembly during mitosis.


Assuntos
Microtúbulos/metabolismo , Proteínas Nucleares/metabolismo , Fuso Acromático/metabolismo , Proteínas de Xenopus , Proteína ran de Ligação ao GTP/metabolismo , Animais , Extratos Celulares , Núcleo Celular/metabolismo , Guanosina Trifosfato/metabolismo , Interfase , Carioferinas , Microtúbulos/efeitos dos fármacos , Mitose , Modelos Biológicos , Proteínas Nucleares/farmacologia , Óvulo , Paclitaxel/farmacologia , Proteínas Recombinantes de Fusão/metabolismo , Fuso Acromático/efeitos dos fármacos , Xenopus
11.
Trends Biochem Sci ; 19(5): 211-6, 1994 May.
Artigo em Inglês | MEDLINE | ID: mdl-7519373

RESUMO

Ran is the only known member of the Ras superfamily of small GTP-binding proteins to be localized primarily inside the nucleus. Recently, Ran was unexpectedly identified as one of the soluble factors required for nuclear import. As this protein has also been implicated in RNA export, nuclear import and export may be more closely related than previously thought, with Ran playing a key role in each.


Assuntos
Núcleo Celular/metabolismo , Citoplasma/metabolismo , Proteínas de Ligação ao GTP/fisiologia , Proteínas Nucleares/fisiologia , Animais , Transporte Biológico , GTP Fosfo-Hidrolases/metabolismo , Proteínas Nucleares/química , RNA/metabolismo , Proteína ran de Ligação ao GTP
12.
J Intellect Disabil Res ; 52(Pt 3): 244-55, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18261023

RESUMO

BACKGROUND: Down syndrome (DS) is characterized by impaired memory span, particularly auditory verbal memory span. Memory span is linked developmentally to several language capabilities, and may be a basic capacity that enables language learning. If children with DS had better memory span, they might benefit more from language intervention. The present study evaluates a home-based parent-implemented intervention designed to improve auditory memory span in children with DS. METHOD: Sixteen children with DS, age 6-14, completed one or two 3-month periods of memory training using overt cumulative rehearsal and auditory-only procedures. Children were divided into two groups. Group 1 completed 3 months of memory training followed by 3 months of visual activities, followed by three more months of memory training. Group 2 had the opposite schedule. Before and after each 3-month period, children came into the laboratory for memory assessment. RESULTS: Children improved in training sessions and a small amount on digit span, the primary proximal outcome assessment measure. Digit span improvement was linked to the memory training, as indicated by control comparisons and correlations. Improvement was correlated with language comprehension and verbal working memory, but not with non-verbal ability, age or home/behavioural variables. No improvement was evident on distal outcome measures (sentence memory and verbal working memory); however, a phonological similarity effect emerged coincidence with memory training, suggesting increased use of phonological codes in memory. CONCLUSIONS: Results suggest that some children with DS can improve their auditory verbal memory span with home-based rehearsal training, at least in limited ways. Children with good language and verbal working memory skills may be the best candidates for this type of training, even though they may show only small improvements. Still, small improvements in a severely impaired function are noteworthy, and justify further investigation.


Assuntos
Síndrome de Down/complicações , Síndrome de Down/psicologia , Transtornos da Memória/etiologia , Transtornos da Memória/reabilitação , Memória de Curto Prazo , Adolescente , Criança , Cognição , Feminino , Humanos , Masculino , Transtornos da Memória/psicologia , Pais , Prática Psicológica , Análise e Desempenho de Tarefas , Resultado do Tratamento , Aprendizagem Verbal
13.
Curr Biol ; 10(4): 187-94, 2000 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-10704411

RESUMO

BACKGROUND: Drugs of abuse have a common property in mammals, which is their ability to facilitate the release of the neurotransmitter and neuromodulator dopamine in specific brain regions involved in reward and motivation. This increase in synaptic dopamine levels is believed to act as a positive reinforcer and to mediate some of the acute responses to drugs. The mechanisms by which dopamine regulates acute drug responses and addiction remain unknown. RESULTS: We present evidence that dopamine plays a role in the responses of Drosophila to cocaine, nicotine or ethanol. We used a startle-induced negative geotaxis assay and a locomotor tracking system to measure the effect of psychostimulants on fly behavior. Using these assays, we show that acute responses to cocaine and nicotine are blunted by pharmacologically induced reductions in dopamine levels. Cocaine and nicotine showed a high degree of synergy in their effects, which is consistent with an action through convergent pathways. In addition, we found that dopamine is involved in the acute locomotor-activating effect, but not the sedating effect, of ethanol. CONCLUSIONS: We show that in Drosophila, as in mammals, dopaminergic pathways play a role in modulating specific behavioral responses to cocaine, nicotine or ethanol. We therefore suggest that Drosophila can be used as a genetically tractable model system in which to study the mechanisms underlying behavioral responses to multiple drugs of abuse.


Assuntos
Cocaína/metabolismo , Dopamina/metabolismo , Etanol/metabolismo , Nicotina/metabolismo , Animais , Comportamento Animal , Dopamina/fisiologia , Drosophila/metabolismo , Masculino
14.
Mol Cell Biol ; 15(4): 2117-24, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7891706

RESUMO

The small Ras-related GTP binding and hydrolyzing protein Ran has been implicated in a variety of processes, including cell cycle progression, DNA synthesis, RNA processing, and nuclear-cytosolic trafficking of both RNA and proteins. Like other small GTPases, Ran appears to function as a switch: Ran-GTP and Ran-GDP levels are regulated both by guanine nucleotide exchange factors and GTPase activating proteins, and Ran-GTP and Ran-GDP interact differentially with one or more effectors. One such putative effector, Ran-binding protein 1 (RanBP1), interacts selectively with Ran-GTP. Ran proteins contain a diagnostic short, acidic, carboxyl-terminal domain, DEDDDL, which, at least in the case of human Ran, is required for its role in cell cycle regulation. We show here that this domain is required for the interaction between Ran and RanBP1 but not for the interaction between Ran and a Ran guanine nucleotide exchange factor or between Ran and a Ran GTPase activating protein. In addition, Ran lacking this carboxyl-terminal domain functions normally in an in vitro nuclear protein import assay. We also show that RanBP1 interacts with the mammalian homolog of yeast protein RNA1, a protein involved in RNA transport and processing. These results are consistent with the hypothesis that Ran functions directly in at least two pathways, one, dependent on RanBP1, that affects cell cycle progression and RNA export, and another, independent of RanBP1, that affects nuclear protein import.


Assuntos
Proteínas de Ciclo Celular , GTP Fosfo-Hidrolases/metabolismo , Proteínas Ativadoras de GTPase , Fatores de Troca do Nucleotídeo Guanina , Proteínas Nucleares/metabolismo , Processamento Pós-Transcricional do RNA , Sequência de Aminoácidos , Animais , Sequência de Bases , Transporte Biológico , Proteínas de Ligação a DNA/metabolismo , Proteínas Fúngicas/metabolismo , Guanosina Trifosfato/metabolismo , Humanos , Camundongos , Mitose/fisiologia , Modelos Biológicos , Dados de Sequência Molecular , Mutação , Proteínas Nucleares/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas de Saccharomyces cerevisiae , Homologia de Sequência de Aminoácidos , Relação Estrutura-Atividade , Leveduras , Proteína ran de Ligação ao GTP
15.
Mol Biol Cell ; 8(12): 2591-604, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9398678

RESUMO

Ran, the small, predominantly nuclear GTPase, has been implicated in the regulation of a variety of cellular processes including cell cycle progression, nuclear-cytoplasmic trafficking of RNA and protein, nuclear structure, and DNA synthesis. It is not known whether Ran functions directly in each process or whether many of its roles may be secondary to a direct role in only one, for example, nuclear protein import. To identify biochemical links between Ran and its functional target(s), we have generated and examined the properties of a putative Ran effector mutation, T42A-Ran. T42A-Ran binds guanine nucleotides as well as wild-type Ran and responds as well as wild-type Ran to GTP or GDP exchange stimulated by the Ran-specific guanine nucleotide exchange factor, RCC1. T42A-Ran.GDP also retains the ability to bind p10/NTF2, a component of the nuclear import pathway. In contrast to wild-type Ran, T42A-Ran.GTP binds very weakly or not detectably to three proposed Ran effectors, Ran-binding protein 1 (RanBP1), Ran-binding protein 2 (RanBP2, a nucleoporin), and karyopherin beta (a component of the nuclear protein import pathway), and is not stimulated to hydrolyze bound GTP by Ran GTPase-activating protein, RanGAP1. Also in contrast to wild-type Ran, T42A-Ran does not stimulate nuclear protein import in a digitonin permeabilized cell assay and also inhibits wild-type Ran function in this system. However, the T42A mutation does not block the docking of karyophilic substrates at the nuclear pore. These properties of T42A-Ran are consistent with its classification as an effector mutant and define the exposed region of Ran containing the mutation as a probable effector loop.


Assuntos
Substituição de Aminoácidos/genética , Proteínas de Ciclo Celular , Fatores de Troca do Nucleotídeo Guanina , Complexo de Proteínas Formadoras de Poros Nucleares , Proteínas Nucleares/metabolismo , Proteínas de Transporte Nucleocitoplasmático , Proteína ran de Ligação ao GTP/genética , Proteína ran de Ligação ao GTP/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Proteínas de Transporte/metabolismo , Proteínas de Transporte/farmacologia , Permeabilidade da Membrana Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Digitonina/farmacologia , Proteínas Ativadoras de GTPase/metabolismo , Guanosina Difosfato/metabolismo , Guanosina Trifosfato/metabolismo , Hidrólise , Fígado/citologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Chaperonas Moleculares , Mutação/genética , Membrana Nuclear/efeitos dos fármacos , Membrana Nuclear/metabolismo , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/farmacologia , Ligação Proteica , Ratos , Proteínas Recombinantes de Fusão/antagonistas & inibidores , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , beta Carioferinas , Proteína ran de Ligação ao GTP/antagonistas & inibidores , Proteína ran de Ligação ao GTP/química
16.
J Mol Biol ; 289(3): 565-77, 1999 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-10356329

RESUMO

Nuclear protein import requires a precisely choreographed series of interactions between nuclear pore components and soluble factors such as importin-beta, Ran, and nuclear transport factor 2 (NTF2). We used the crystal structure of the GDPRan-NTF2 complex to design mutants in the switch II loop of Ran to probe the contribution of Lys71, Phe72 and Arg76 to this interaction. X-ray crystallography showed that the F72Y, F72W and R76E mutations did not introduce major structural changes into the mutant Ran. The GDP-bound form of the switch II mutants showed no detectable binding to NTF2, providing direct evidence that salt bridges involving Lys71 and Arg76 and burying Phe72 are all crucial for the interaction between Ran and NTF2. Nuclear protein accumulation in digitonin-permeabilzed cells was impaired with Ran mutants deficient in NTF2 binding, confirming that the NTF2-Ran interaction is required for efficient transport. We used mutants of the yeast Ran homologue Gsp1p to investigate the effect of the F72Y and R76E mutations in vivo. Although neither mutant was viable when integrated into the genome as a single copy, yeast mildly overexpressing the Gsp1p mutant corresponding Ran F72Y on a centromeric plasmid were viable, confirming that this mutant retained the essential properties of wild-type Ran. However, yeast expressing the Gsp1p mutant corresponding to R76E to comparable levels were not viable, although strains overexpressing the mutant to higher levels using an episomal 2micrometers plasmid were viable, indicating that the R76E mutation may also have interfered with other interactions made by Gsp1p.


Assuntos
Proteínas de Transporte/metabolismo , Núcleo Celular/metabolismo , Proteínas Monoméricas de Ligação ao GTP , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas de Transporte Nucleocitoplasmático , Proteínas de Saccharomyces cerevisiae , Animais , Transporte Biológico , Proteínas de Transporte/química , Linhagem Celular/metabolismo , Permeabilidade da Membrana Celular , Cristalografia por Raios X , GTP Fosfo-Hidrolases/química , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Proteínas de Ligação ao GTP/genética , Proteínas de Ligação ao GTP/metabolismo , Regulação Fúngica da Expressão Gênica , Guanosina Trifosfato/metabolismo , Modelos Moleculares , Mutação , Proteínas Nucleares/química , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Leveduras/genética , Leveduras/metabolismo , Proteína ran de Ligação ao GTP
17.
Essays Biochem ; 36: 105-13, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-12471906

RESUMO

Many proteins show distinct nuclear- and cytoplasmic-localization patterns. For proteins above the diffusion limit of the NPC, this localization is governed by the activity of NLSs and/or NESs contained in the protein. Structural modification of proteins can affect NLS and NES activities. Ligand binding, phosphorylation and proteolysis are each capable of modifying the nucleocytoplasmic distribution of proteins. In the case of transcription factors, control of these structural modifications affects access of the transcription factor to the chromatin. This management of cellular distribution, in turn, regulates gene expression.


Assuntos
Transporte Ativo do Núcleo Celular/fisiologia , Regulação da Expressão Gênica/fisiologia , Animais , Proteínas de Transporte/metabolismo , Núcleo Celular , Humanos , Proteínas Nucleares/fisiologia
18.
Arch Gen Psychiatry ; 32(12): 1483-97, 1975 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1200768

RESUMO

Radical psychiatrists and others assert that mental illness is a myth. The opening and closing portions of the article deal with the impact such an argument has had in law and psychiatry. The body of the article discusses the five following versions of the myth argument prevalent in radical psychiatry: (1) that there is no such thing as mental illness; (2) that those called "mentally ill" are really as rational as everyone else, only with different aims, that the only reasons anyone ever thought differently was (3) because of unsophisticated category mistakes or (4) because of an adherence to the epistemology of a sick society; and (5) that the phrase "mental illness" is used to mask value judgments about others' behavior in pseudoscientific respectability. Reasons are given for rejecting each of these versions of the argument that mental illness is a myth.


Assuntos
Transtornos Mentais , Terminologia como Assunto , Psiquiatria Legal , Humanos , Transtornos Mentais/diagnóstico , Psiquiatria , Teoria Psicológica , Esquizofrenia/diagnóstico , Psicologia do Esquizofrênico
19.
Eur J Clin Nutr ; 69(12): 1344-5, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26130299

RESUMO

Following periods of physical activity, it is not uncommon for exercisers to increase their energy intake as a reward deemed 'earned'. Consumers' awareness of the energy within food and expended from exercise has previously been found to be limited. Therefore, the aim was to investigate whether habitual exercisers (50 adults and 49 children from 5 sports clubs) were able to conceptualise the energy expenditure (EE), following 1 h of their regular sports training, into a quantifiable amount of perceived energy compensation (PEC) in the form of food (chocolate) or drink (sports drink). Mean percentage accuracy for the PEC against EE matched <30% (± 29%), a significant underestimation irrespective of sex or sport. Percentage accuracy failed to significantly correlate to age. These findings indicate a necessity to improve nutrition education surrounding the energy costs of exercise relative to the energy contained within foods/drinks for both adults and children.


Assuntos
Ingestão de Energia , Metabolismo Energético , Exercício Físico , Esportes , Adolescente , Adulto , Fatores Etários , Bebidas , Índice de Massa Corporal , Criança , Feminino , Alimentos , Futebol Americano , Hóquei , Humanos , Masculino , Pessoa de Meia-Idade , Esportes com Raquete , Fatores Sexuais , Natação , Adulto Jovem
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