Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 50
Filtrar
1.
Phys Rev Lett ; 114(5): 054801, 2015 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-25699448

RESUMO

The Linac Coherent Light Source has added a self-seeding capability to the soft x-ray range using a grating monochromator system. We report the demonstration of soft x-ray self-seeding with a measured resolving power of 2000-5000, wavelength stability of 10(-4), and an increase in peak brightness by a factor of 2-5 across the photon energy range of 500-1000 eV. By avoiding the need for a monochromator at the experimental station, the self-seeded beam can deliver as much as 50-fold higher brightness to users.

2.
Clin Diagn Lab Immunol ; 12(12): 1410-5, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16339064

RESUMO

Several serology-based immunoassays are used to diagnose visceral leishmaniasis (VL), a chronic protozoan parasitic disease caused by the Leishmania donovani complex. These tests are primarily designed to diagnose the most severe clinical form of VL, known as kala-azar. However, leishmanial infection is frequently asymptomatic and may manifest only as a positive serologic response or positive leishmanin skin test. We modified a previously described enzyme-linked immunosorbent assay (ELISA) that detects patient antibodies reactive with the recombinant Leishmania protein K39 (rK39) to confirm suspected kala-azar and to detect asymptomatic infection in a community study in Bangladesh. With the inclusion of a standard curve on each ELISA plate, the rK39 ELISA was more repeatable (kappa coefficient of agreement=0.970) and more reliable compared to the original method (kappa=0.587, P<0.001). The cutoff point for a positive antibody response was chosen based on the 99th percentile of the ELISA distribution for the negative-control sera. However, we found that sera from all patients with active kala-azar yielded values more than twice the magnitude of this cutoff. Using receiver-operator characteristic curves, we determined a second cutoff value predictive of kala-azar. Using these criteria, the sensitivity and specificity of the modified ELISA for kala-azar were 97.0% and 98.9%, respectively, for sera from our study population. We hypothesize that individuals with antibody levels greater than the 99th percentile of the negative controls but less than the cutoff point for kala-azar have asymptomatic leishmanial infections.


Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Leishmania donovani/imunologia , Leishmaniose Visceral/diagnóstico , Proteínas de Protozoários/imunologia , Animais , Bangladesh , Humanos , Leishmaniose Visceral/imunologia , Proteínas Recombinantes , Sensibilidade e Especificidade
3.
An. psiquiatr ; 20(10): 422-428, nov. 2004. tab
Artigo em Es | IBECS | ID: ibc-37586

RESUMO

El objetivo de este estudio es investigar los cambios en los patrones de las demandas de interconsulta psiquiátrica en un hospital general. Presentamos un estudio longitudinal de 12 años de seguimiento (1992-2003) de dichas demandas. Se mantienen unos índices de derivaciones del 2 por ciento de los ingresos hospitalarios, con predominio de sujetos mayores de 65 años. Hay un incremento de las derivaciones de las áreas médicas frente a las quirúrgicas; a nivel diagnóstico se aprecia una reducción de los cuadros confusionales y un incremento de los trastornos derivados del consumo de alcohol, con estabilidad en la frecuencia de trastornos adaptativos, afectivos, y por ansiedad. El tratamiento psicofarmacológico constituye la intervención psiquiátrica más habitual y se aprecia una modificación en el patrón de empleo de algunos psicofármacos, con reducción de la prescripción de neurolépticos e incremento de la de benzodiacepinas (AU)


Assuntos
Humanos , Hospitais Gerais/estatística & dados numéricos , Unidade Hospitalar de Psiquiatria/estatística & dados numéricos , Transtornos Mentais/epidemiologia , Encaminhamento e Consulta/estatística & dados numéricos , Estudos Longitudinais , Consumo de Bebidas Alcoólicas/epidemiologia , Psicotrópicos/uso terapêutico
4.
Environ Microbiol ; 6(9): 887-902, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15305914

RESUMO

Desulfotalea psychrophila is a marine sulfate-reducing delta-proteobacterium that is able to grow at in situ temperatures below 0 degrees C. As abundant members of the microbial community in permanently cold marine sediments, D. psychrophila-like bacteria contribute to the global cycles of carbon and sulfur. Here, we describe the genome sequence of D. psychrophila strain LSv54, which consists of a 3 523 383 bp circular chromosome with 3118 predicted genes and two plasmids of 121 586 bp and 14 663 bp. Analysis of the genome gave insight into the metabolic properties of the organism, e.g. the presence of TRAP-T systems as a major route for the uptake of C(4)-dicarboxylates, the unexpected presence of genes from the TCA cycle, a TAT secretion system, the lack of a beta-oxidation complex and typical Desulfovibrio cytochromes, such as c(553), c(3) and ncc. D. psychrophila encodes more than 30 two-component regulatory systems, including a new Ntr subcluster of hybrid kinases, nine putative cold shock proteins and nine potentially cold shock-inducible proteins. A comparison of D. psychrophila's genome features with those of the only other published genome from a sulfate reducer, the hyperthermophilic archaeon Archaeoglobus fulgidus, revealed many striking differences, but only a few shared features.


Assuntos
Proteínas de Bactérias/metabolismo , Mapeamento Cromossômico , Deltaproteobacteria/genética , Genoma Bacteriano , Sedimentos Geológicos/microbiologia , Regiões Árticas , Proteínas de Bactérias/genética , Composição de Bases , Sequência de Bases , Congelamento , Ordem dos Genes , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA
5.
Phys Rev Lett ; 92(15): 151101, 2004 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-15169276

RESUMO

We have measured the cosmic ray spectrum above 10(17.2) eV using the two air-fluorescence detectors of the High Resolution Fly's Eye observatory operating in monocular mode. We describe the detector, phototube, and atmospheric calibrations, as well as the analysis techniques for the two detectors. We fit the spectrum to a model consisting of galactic and extragalactic sources.

6.
Cancer Chemother Pharmacol ; 48 Suppl 1: S31-4, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11587363

RESUMO

AML-1 is one of the most frequently translocated genes in human leukemia. AML-1 binds DNA and activates or represses transcription, while the chromosomal translocation fusion proteins in acute myeloid leukemia subvert these functions. The t(8;21) is the second most frequent translocation in acute myeloid leukemia and creates a fusion between the DNA binding domain of AML-1 and the ETO (also known as MTG8) corepressor. The t(12;21) is found in up to 25% of pediatric B cell acute lymphoblastic leukemias and fuses the ETS family transcription factor TEL to the amino terminus of AML-1. In addition, the inv(16), the most frequent translocation in acute myeloid leukemia, fuses the AML-1 cofactor CBFbeta to the smooth muscle myosin heavy chain MYH11. Both the t(8;21) and t(12;21) create transcriptional repressors that impair AML-1 target gene expression. We demonstrated that the fusion proteins encoded by these translocations contact the nuclear hormone corepressors (N-CoR/SMRT), mSin3A, and histone deacetylases. We have also found that both TEL and AML-1 interact with mSin3A. TEL also binds N-CoR and histone deacetylase-3, indicating that wild-type TEL is a transcriptional repressor. The t(12;21) fuses the mSin3A interaction domain of TEL to AML-1 to transform AML-1 from a regulated to an unregulated transcriptional repressor. The recognition that AML-1 interacts with mSin3A to repress transcription suggested that the inv(16) fusion protein might also repress the transcription of AML-1-target genes. In fact, the inv(16) encodes a protein that cooperates with AML-1 to repress transcription. The inv(16) fusion protein was found in a ternary complex with AML-1 and mSin3A, suggesting that the inv(16) also acts by recruiting transcriptional corepressors and histone deacetylases.


Assuntos
Proteínas de Fusão Oncogênica/fisiologia , Proteínas Repressoras/fisiologia , Transcrição Gênica/fisiologia , Células 3T3 , Animais , Células COS , Inversão Cromossômica , Cromossomos Humanos Par 12 , Cromossomos Humanos Par 16 , Cromossomos Humanos Par 18 , Cromossomos Humanos Par 21 , Subunidade alfa 2 de Fator de Ligação ao Core , Humanos , Camundongos , Proteínas Nucleares/metabolismo , Correpressor 1 de Receptor Nuclear , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Proteína 1 Parceira de Translocação de RUNX1 , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/fisiologia , Translocação Genética
7.
Mol Cell Biol ; 21(19): 6470-83, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11533236

RESUMO

t(8;21) and t(16;21) create two fusion proteins, AML-1-ETO and AML-1-MTG16, respectively, which fuse the AML-1 DNA binding domain to putative transcriptional corepressors, ETO and MTG16. Here, we show that distinct domains of ETO contact the mSin3A and N-CoR corepressors and define two binding sites within ETO for each of these corepressors. In addition, of eight histone deacetylases (HDACs) tested, only the class I HDACs HDAC-1, HDAC-2, and HDAC-3 bind ETO. However, these HDACs bind ETO through different domains. We also show that the murine homologue of MTG16, ETO-2, is also a transcriptional corepressor that works through a similar but distinct mechanism. Like ETO, ETO-2 interacts with N-CoR, but ETO-2 fails to bind mSin3A. Furthermore, ETO-2 binds HDAC-1, HDAC-2, and HDAC-3 but also interacts with HDAC-6 and HDAC-8. In addition, we show that expression of AML-1-ETO causes disruption of the cell cycle in the G(1) phase. Disruption of the cell cycle required the ability of AML-1-ETO to repress transcription because a mutant of AML-1-ETO, Delta469, which removes the majority of the corepressor binding sites, had no phenotype. Moreover, treatment of AML-1-ETO-expressing cells with trichostatin A, an HDAC inhibitor, restored cell cycle control. Thus, AML-1-ETO makes distinct contacts with multiple HDACs and an HDAC inhibitor biologically inactivates this fusion protein.


Assuntos
Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Histona Desacetilases/metabolismo , Leucemia Mielomonocítica Aguda/genética , Proteínas de Fusão Oncogênica/fisiologia , Proteínas Proto-Oncogênicas , Proteínas Repressoras/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Fatores de Transcrição/fisiologia , Sequência de Aminoácidos , Animais , Sítios de Ligação , Linhagem Celular , Subunidade alfa 2 de Fator de Ligação ao Core , Proteínas de Ligação a DNA/fisiologia , Inibidores Enzimáticos/farmacologia , Inibidores de Histona Desacetilases , Ácidos Hidroxâmicos/farmacologia , Camundongos , Modelos Genéticos , Dados de Sequência Molecular , Proteínas Nucleares/metabolismo , Proteínas Nucleares/fisiologia , Correpressor 1 de Receptor Nuclear , Proteínas de Fusão Oncogênica/antagonistas & inibidores , Estrutura Terciária de Proteína , Proteína 1 Parceira de Translocação de RUNX1 , Homologia de Sequência de Aminoácidos , Complexo Correpressor Histona Desacetilase e Sin3 , Fatores de Transcrição/antagonistas & inibidores , Transcrição Gênica , Translocação Genética
8.
Curr Opin Hematol ; 8(4): 197-200, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11561155

RESUMO

The t(8;21), t(16;21), inv(16), and t(12;21) are some of the most frequent chromosomal translocations found in acute myeloid and acute lymphoblastic leukemia. The fusion proteins created by these chromosomal translocations are transcriptional repressors. A full understanding of the types of proteins that these fusion proteins recruit to repress transcription will not only clarify understanding of the molecular mechanism of action of these fusion proteins but also provide further targets for therapeutic intervention.


Assuntos
Leucemia Mieloide/genética , Proteínas de Fusão Oncogênica/fisiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Doença Aguda , Subunidade alfa 2 de Fator de Ligação ao Core , Regulação Neoplásica da Expressão Gênica , Humanos , Proteína 1 Parceira de Translocação de RUNX1 , Proteínas Repressoras/fisiologia , Fatores de Transcrição/fisiologia , Transcrição Gênica , Translocação Genética
9.
Epilepsy Res ; 45(1-3): 133-6; discussion 137-40, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11461814

RESUMO

Over 20% of epilepsies in children are intractable, and are frequently associated with deterioration of motor and cognitive functions. Some are similar to those seen in adults, but many age-related epilepsies occur only in children. Therefore, a sizeable proportion of intractable epilepsies of childhood are different from those encountered in adults, and there is an urgent need for antiepileptic drug trials to be undertaken in children at an early stage of development. An ethical framework within which these trials can be conducted has been defined.


Assuntos
Anticonvulsivantes/uso terapêutico , Epilepsia/tratamento farmacológico , Criança , Ensaios Clínicos como Assunto , Humanos
10.
J Appl Physiol (1985) ; 90(2): 501-10, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11160048

RESUMO

Exercise training produces enhanced nitric oxide (NO)-dependent, endothelium-mediated vasodilator responses of porcine coronary arterioles but not conduit coronary arteries. The purpose of this study was to test the hypothesis that exercise training increases the amount of endothelial NO synthase (eNOS) in the coronary arterial microcirculation but not in the conduit coronary arteries. Miniature swine were either exercise trained or remained sedentary for 16--20 wk. Exercise-trained pigs exhibited increased skeletal muscle oxidative capacity, exercise tolerance, and heart weight-to-body weight ratios. Content of eNOS protein was determined with immunoblot analysis in conduit coronary arteries (2- to 3-mm ID), small arteries (301- to 1,000-microm ID), resistance arteries (151- to 300-microm ID), and three sizes of coronary arterioles [large (101- to 150-microm ID), intermediate (51- to 100-microm ID), and small (<50-microm ID)]. Immunoblots revealed increased eNOS protein in some sizes of coronary arteries and arterioles but not in others. Content of eNOS was increased by 60--80% in small and large arterioles, resistance arteries, and small arteries; was increased by 10--20% in intermediate-sized arterioles; and was not changed or decreased in conduit arteries. Immunohistochemistry revealed that eNOS was located in the endothelial cells in all sizes of coronary artery. We conclude that exercise training increases eNOS protein expression in a nonuniform manner throughout the coronary arterial tree. Regional differences in shear stress and intraluminal pressures during exercise training bouts may be responsible for the distribution of increased eNOS protein content in the coronary arterial tree.


Assuntos
Vasos Coronários/enzimologia , Endotélio Vascular/enzimologia , Óxido Nítrico Sintase/biossíntese , Esforço Físico , Animais , Artérias/anatomia & histologia , Artérias/enzimologia , Arteríolas/anatomia & histologia , Arteríolas/enzimologia , Vasos Coronários/anatomia & histologia , Teste de Esforço , Tolerância ao Exercício , Feminino , Immunoblotting/métodos , Imuno-Histoquímica , Óxido Nítrico Sintase/imunologia , Suínos
11.
Ophthalmologe ; 97(11): 737-41, 2000 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-11130160

RESUMO

BACKGROUND: The long-acting somatostatin analogue octreotide is used as a therapeutic option for patients with diabetic retinopathy and age-related macular degeneration. Growth factors, such as EGF, bFGF, VEGF, and PDGF, have been implicated in the pathogenesis of these diseases. The aim of this study was to investigate the effect of octreotide on the growth-factor-induced proliferation of bovine retinal pigment epithelial (RPE) cells in vitro. METHODS: RPE cells were assayed for proliferation as measured by (3H)-thymidine uptake (ccpm). Bovine RPE cells at passage 3-8 were seeded in a 96-well plate and incubated for a 24-h period with a minimum medium followed by a 24-h incubation with the different growth factors at a concentration of 10 ng/ml with and without 5 x 10(-5) M octreotide. In a different assay the cells were incubated with octreotide at 5 x 10(-10)-5 x 10(-4) M. Afterwards the cells were pulsed with 5 microCi/ml (3H)-thymidine for 12 h, and the incorporated radioactivity was measured on glass fiber filters in a beta-counter (mean +/- SEM ccpm). The Wilcoxon Signed Rank test and the student's t-test were used for statistical analyses. RESULTS: There was a biphasic effect of octreotide on RPE cell proliferation. Exposure of RPE cells to PDGF (20,225 +/- 3304 ccpm) and bFGF (3441 +/- 539 ccpm) resulted in a significantly higher proliferation compared to control medium (1543 +/- 352 ccpm) (p < 0.05). No difference was found for EGF (2385 +/- 383 ccpm). For VEGF (776 +/- 83 ccpm) a significant reduction in RPE cell proliferation was found (P < 0.05). There was a significant reduction in proliferation of RPE cells with PDGF, bFGF, and EGF in combination with octreotide versus growth factors alone (octreotide in combination with PDGF 308 +/- 82 ccpm, with bFGF 229 +/- 88 ccpm, with EGF 2362 +/- 91 ccpm) (p < 0.005). VEGF in combination with octreotide resulted in a significant inhibition of RPE cell proliferation compared to VEGF alone (p < 0.0005). CONCLUSION: The data suggest that there is an inhibitory effect of octreotide on RPE cell proliferation of bovine RPE cells and on the increased proliferation of bovine RPE cells induced by PDGF and bFGF. An enhanced inhibitory effect is found for the combination of octreotide and VEGF.


Assuntos
Divisão Celular/efeitos dos fármacos , Substâncias de Crescimento/farmacologia , Octreotida/farmacologia , Epitélio Pigmentado Ocular/citologia , Animais , Bovinos , Células Cultivadas , Relação Dose-Resposta a Droga , Técnicas In Vitro , Epitélio Pigmentado Ocular/efeitos dos fármacos
12.
Ophthalmic Res ; 32(5): 244-8, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10971188

RESUMO

BACKGROUND: The retinal pigment epithelium (RPE) has been implicated in the development of diabetic retinopathy and it has been suggested that insulin-like growth factors (IGF) and glucose may be among those factors which are responsible for the RPE changes in diabetics. The purpose of this study was to investigate the effect of IGF-1, IGF-2, and glucose on the migration and proliferation of bovine RPE cells in vitro. METHODS: Primary cultures of bovine RPE cells were established from freshly enucleated eyes and passages 5-8 were used for these experiments. RPE cell migration was studied in confluent RPE cultures grown in multiwell plates. After inhibition of proliferation with mitomycin C (10 microg/ml) and partial denudation of the RPE in each well, the cells were incubated with IGF-1 (10 ng/ml), IGF-2 (10 ng/ml) or glucose (10 mM). Migration was measured as the number of cells that had entered the denuded area after 20 h. RPE cell proliferation was determined by [(3)H]-thymidine incorporation after incubation with IGF-1, IGF-2, and glucose for 24 h. Statistical analysis was performed with the paired Student's t test. RESULTS: Exposure of RPE cells to IGF-1, IGF-2, and glucose resulted in a significantly higher RPE cell migration as compared to the control medium (p < 0.008) with 21, 20, 17, and 9 cells/raster field, respectively. Additionally, IGF-1 (p = 0.004) and IGF-2 (p = 0.008) but not glucose caused a statistically significant stimulation of DNA synthesis with 761, 747, and 593 ccpm, respectively, as compared to the negative control (352 ccpm). CONCLUSION: This study indicates that IGF-1 and IGF-2 influence RPE cell migration and proliferation. This is further evidence that these factors are among those which have to be kept in mind when trying to modulate the development of diabetic eye diseases.


Assuntos
Glucose/farmacologia , Fator de Crescimento Insulin-Like II/farmacologia , Fator de Crescimento Insulin-Like I/farmacologia , Epitélio Pigmentado Ocular/citologia , Animais , Bovinos , Técnicas de Cultura de Células , Divisão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Epitélio Pigmentado Ocular/efeitos dos fármacos
13.
Mol Cell Biol ; 20(16): 5828-39, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10913166

RESUMO

TEL is a member of the ETS family of transcription factors that interacts with the mSin3 and SMRT corepressors to regulate transcription. TEL is biallelically disrupted in acute leukemia, and loss of heterozygosity at the TEL locus has been observed in various cancers. Here we show that expression of TEL in Ras-transformed NIH 3T3 cells inhibits cell growth in soft agar and in normal cultures. Unexpectedly, cells expressing both Ras and TEL grew as aggregates. To begin to explain the morphology of Ras-plus TEL-expressing cells, we demonstrated that the endogenous matrix metalloproteinase stromelysin-1 was repressed by TEL. TEL bound sequences in the stromelysin-1 promoter and repressed the promoter in transient-expression assays, suggesting that it is a direct target for TEL-mediated regulation. Mutants of TEL that removed a binding site for the mSin3A corepressor but retained the ETS domain failed to repress stromelysin-1. When BB-94, a matrix metalloproteinase inhibitor, was added to the culture medium of Ras-expressing cells, it caused a cell aggregation phenotype similar to that caused by TEL expression. In addition, TEL inhibited the invasiveness of Ras-transformed cells in vitro and in vivo. Our results suggest that TEL acts as a tumor suppressor, in part, by transcriptional repression of stromelysin-1.


Assuntos
Proteínas de Ligação a DNA/genética , Genes ras , Metaloproteinase 3 da Matriz/genética , Proteínas Repressoras , Fatores de Transcrição/genética , Ativação Transcricional , Células 3T3 , Animais , Divisão Celular/genética , Transformação Celular Neoplásica/genética , Genes Supressores de Tumor , Camundongos , Proteínas Proto-Oncogênicas c-ets , Variante 6 da Proteína do Fator de Translocação ETS
14.
J Craniofac Genet Dev Biol ; 20(1): 26-34, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10879655

RESUMO

Protein kinase C (PKC) plays a critical role in signal transduction, mediating various cellular events critical for normal development, including that of the palate. In vivo and in vitro studies suggest the relevance of the inhibition of PKC by the mycotoxin, secalonic acid D (SAD), to its induction of cleft palate (CP) in mice. In the present study, temporal and spatial expression and the activity of various PKC isoenzymes were studied in the control and SAD-exposed murine embryonic palate during gestational days (GD) 12-14.5 by western blotting, immunohistochemistry, and phosphotransfer assay. The Ca2+-dependent isoenzymes, PKC alpha and PKC betaII, showed significant expression on GD 12.0, which gradually decreased through GD 14.5, whereas PKC betaI and PKC gamma were negligible throughout. All Ca2+-independent isoenzymes (epsilon, delta, and zeta) were expressed more abundantly and, in contrast to the Ca2+-dependent ones, progressively increased with age. SAD failed to alter this pattern of expression but enhanced the phosphorylation of PKC epsilon throughout development. Immunohistochemical analysis revealed an isoenzyme-specific distribution of PKC between the epithelium and mesenchyme. As expected, SAD significantly inhibited the total Ca2+-dependent PKC activity in palatal extracts. Although total Ca2+-independent PKC activity in palatal extracts was unaffected by SAD, individual pure isoenzymes were either selectively inhibited (PKC zeta), stimulated (PKC delta), or unaffected (PKC epsilon) by SAD. These results show that PKC isoenzymes exhibit dynamic temporal and spatial patterns of expression and activity in the developing palate and that the induction of CP by SAD is associated with an alteration in their activation and/or activity.


Assuntos
Isoenzimas , Proteína Quinase C/biossíntese , Proteína Quinase C/metabolismo , Xantonas , Animais , Western Blotting , Fissura Palatina/genética , Fissura Palatina/metabolismo , Fissura Palatina/patologia , Relação Dose-Resposta a Droga , Feminino , Imuno-Histoquímica , Isoenzimas/metabolismo , Masculino , Camundongos , Palato/anormalidades , Palato/embriologia , Palato/enzimologia , Fosforilação , Fosfotransferases/metabolismo , Proteína Quinase C/química , Proteína Quinase C beta , Proteína Quinase C-alfa , Proteína Quinase C-delta , Proteína Quinase C-épsilon , Transdução de Sinais , Fatores de Tempo , Distribuição Tecidual , Xantenos/metabolismo , Xantenos/farmacologia
15.
Mol Cell Biol ; 19(10): 6566-74, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10490596

RESUMO

t(12;21) is the most frequent translocation found in pediatric B-cell acute lymphoblastic leukemias. This translocation fuses a putative repressor domain from the TEL DNA-binding protein to nearly all of the AML-1B transcription factor. Here, we demonstrate that fusion of the TEL pointed domain to the GAL4 DNA-binding domain resulted in sequence-specific transcriptional repression, indicating that the pointed domain is a portable repression motif. The TEL pointed domain functioned equally well when the GAL4 DNA-binding sites were moved 600 bp from the promoter, suggesting an active mechanism of repression. This lead us to demonstrate that wild-type TEL and the t(12;21) fusion protein bind the mSin3A corepressor. In the fusion protein, both TEL and AML-1B contribute mSin3 interaction domains. Deletion mutagenesis indicated that both the TEL and AML-1B mSin3-binding domains contribute to repression by the fusion protein. While both TEL and AML-1B associate with mSin3A, TEL/AML-1B appears to bind this corepressor much more stably than either wild-type protein, suggesting a mode of action for the t(12;21) fusion protein.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Fusão Oncogênica/genética , Proteínas Proto-Oncogênicas , Proteínas Repressoras/genética , Fatores de Transcrição/genética , Translocação Genética , Linfoma de Burkitt/genética , Criança , Cromossomos Humanos Par 12 , Cromossomos Humanos Par 21 , Subunidade alfa 2 de Fator de Ligação ao Core , Proteínas de Ligação a DNA/metabolismo , Humanos , Modelos Genéticos , Proteínas de Neoplasias , Proteínas de Fusão Oncogênica/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-ets , Proteína 1 Parceira de Translocação de RUNX1 , Proteínas Repressoras/metabolismo , Complexo Correpressor Histona Desacetilase e Sin3 , Fatores de Transcrição/metabolismo , Variante 6 da Proteína do Fator de Translocação ETS
16.
Klin Monbl Augenheilkd ; 214(1): 53-4, 1999 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-10198884

RESUMO

PATIENT: A 60-year-old woman was evaluated for a nodular tumor in her right upper eyelid, which has developed over the last four years. The tumor measured 10 x 8 mm and was ulcerated. The patient's ophthalmologic und medical history was normal. Clinically, a basal cell carcinoma was suspected, and an excision was carried out under local anaesthesia. The histopathology was suggestive for an eccrine spiradenoma. CONCLUSION: Eccrine spiradenomas rarely involve the eyelids. This tumor represents a benign, usually painful, sweat gland tumor. The possibility of sweat gland tumor should be kept in mind in the diagnosis of eyelid tumors. The complete excision is the only therapeutic option.


Assuntos
Adenoma de Glândula Sudorípara/diagnóstico , Neoplasias Palpebrais/diagnóstico , Neoplasias das Glândulas Sudoríparas/diagnóstico , Feminino , Humanos , Pessoa de Meia-Idade
17.
Klin Monbl Augenheilkd ; 215(6): 376-7, 1999 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-10637805

RESUMO

BACKGROUND: A 52-year-old woman was evaluated for a pigmented tumor in her right lower eyelid, which has developed over the last year. The tumor measured 3 x 4 mm. The patient's ophthalmologic and medical history was normal. Clinically, a malignant melanoma was suspected, and an excision was carried out in local anesthesia. The histopathology was suggestive for a deep penetrating nevus. CONCLUSION: Deep penetrating nevus is a variant of benign pigmented nevi with deep dermal and subcutaneous involvement. The pattern should be recognized and differentiated form malignant melanoma.


Assuntos
Neoplasias Palpebrais/diagnóstico , Nevo Pigmentado/diagnóstico , Neoplasias Palpebrais/patologia , Pálpebras/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Invasividade Neoplásica , Nevo Pigmentado/patologia
18.
J Appl Physiol (1985) ; 82(6): 1862-8, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9173951

RESUMO

The primary purpose of this study was to test the hypothesis that endurance exercise training induces increased oxidative capacity in porcine skeletal muscle. To test this hypothesis, female miniature swine were either trained by treadmill running 5 days/wk over 16-20 wk (Trn; n = 35) or pen confined (Sed; n = 33). Myocardial hypertrophy, lower heart rates during submaximal stages of a maximal treadmill running test, and increased running time to exhaustion during that test were indicative of training efficacy. A variety of skeletal muscles were sampled and subsequently assayed for the enzymes citrate synthase (CS), 3-hydroxyacyl-CoA dehydrogenase, and lactate dehydrogenase and for antioxidant enzymes. Fiber type composition of a representative muscle was also determined histochemically. The largest increase in CS activity (62%) was found in the gluteus maximus muscle (Sed, 14.7 +/- 1.1 mumol.min-1.g-1; Trn, 23.9 +/- 1.0; P < 0.0005). Muscles exhibiting increased CS activity, however, were located primarily in the forelimb; ankle and knee extensor and respiratory muscles were unchanged with training. Only two muscles exhibited higher 3-hydroxyacyl-CoA dehydrogenase activity in Trn compared with Sed. Lactate dehydrogenase activity was unchanged with training, as were activities of antioxidant enzymes. Histochemical analysis of the triceps brachii muscle (long head) revealed lower type IIB fiber numbers in Trn (Sed, 42 +/- 6%; Trn, 10 +/- 4; P < 0.01) and greater type IID/X fiber numbers (Sed, 11 +/- 2; Trn, 22 +/- 3; P < 0.025). These findings indicate that porcine skeletal muscle adapts to endurance exercise training in a manner similar to muscle of humans and other animal models, with increased oxidative capacity. Specific muscles exhibiting these adaptations, however, differ between the miniature swine and other species.


Assuntos
Adaptação Fisiológica , Atividade Motora/fisiologia , Músculo Esquelético/metabolismo , Suínos/metabolismo , Animais , Antioxidantes/metabolismo , Metabolismo Energético , Enzimas/metabolismo , Feminino , Fibras Musculares Esqueléticas/classificação , Resistência Física , Porco Miniatura
19.
J Biol Chem ; 272(6): 3823-32, 1997 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-9013641

RESUMO

Helicases are components of numerous protein complexes, including those regulating transcription, translation, DNA replication and repair, splicing, and mitotic chromosome transmission. Helicases unwind double-stranded DNA and RNA homo- and hetero-duplexes. The yeast CHL1 helicase has been linked to maintenance of the high fidelity of chromosome transmission during mitosis. Mutations in this gene result in a 200-fold increase in the rate of aberrant chromosome segregation with a concomitant delay in the cell cycle at G2-M, suggesting that CHL1 is required for the maintenance of proper chromosome transmission. Two highly related human cDNA clones encoding proteins which are homologous to the yeast CHL1 gene product have been isolated. Here we show that these two distinct human CHL1-related mRNAs and proteins (hCHLR1 and hCHLR2) are expressed only in proliferating human cell lines. Quiescent normal human fibroblasts stimulated to re-enter the cell cycle by addition of serum begin to express the CHL1-related proteins as the cells enter S phase, concomitant with the expression of proliferating cell nuclear antigen. Furthermore, expression of the CHL1-related mRNAs is lost when human K562 cells cease to proliferate and terminally differentiate in response to phorbol ester treatments. Human hCHLR expression is not extinguished during hemin-induced differentiation of the same cell line, which produces erythrocyte-like cells that continue to proliferate. These experiments are consistent with the requirement of this putative helicase during either S or G2-M phase but not G1. In vitro transcribed and translated hCHLR1 protein binds to both single- and double-stranded DNA, supporting the possibility that these proteins are DNA helicases. Finally, affinity-purified hCHLR1 antisera was used to demonstrate the localization of the hCHLR proteins to the nucleolus by indirect immunofluorescence as well as by cell fractionation.


Assuntos
Proteínas Cromossômicas não Histona , Proteínas Fúngicas/química , Proteínas de Saccharomyces cerevisiae , Sequência de Aminoácidos , Animais , Western Blotting , Diferenciação Celular , Clonagem Molecular , DNA/metabolismo , DNA Complementar/química , Drosophila melanogaster , Células HeLa , Humanos , Dados de Sequência Molecular , Saccharomyces cerevisiae , Homologia de Sequência de Aminoácidos
20.
J Cataract Refract Surg ; 22(8): 1091-6, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8915814

RESUMO

PURPOSE: To investigate the effect of cataract extraction on ocular hemodynamics. SETTING: University Eye Clinic of Ulm, Germany. METHODS: In 51 consecutive patients assigned for cataract surgery, pulse amplitude, pulse volume, and pulsatile ocular blood flow were measured 1 day before and 3 days and 12 months after cataract extraction using an ocular blood flow tonograph. Statistical analysis was performed with Student's t-test and Wilcoxon signed-rank test. RESULTS: In the study eyes, 3 days after cataract surgery pulse amplitude, pulse volume, and pulsatile ocular blood flow had decreased from 2.5 to 2.1 mm Hg (P = .0014), 5.0 to 4.4 microliters (P = .0059), and 836.2 to 728.0 microliters/min (P = .0017), respectively. No statistically significant change between preoperative and 3 day postoperative measurements occurred in the fellow eyes. There was no significant difference in systemic blood pressure, heart rate, or IOP in study and fellow eyes before and 3 days after cataract surgery. The early reduction of pulse amplitude, pulse volume, and pulsatile ocular blood flow in the study eyes was not present 1 year postoperatively. CONCLUSION: Uncomplicated cataract extraction is associated with a temporary ipsilateral impairment of ocular hemodynamics. A neural mechanism triggered by cataract extraction may be involved in these temporary changes.


Assuntos
Extração de Catarata , Olho/irrigação sanguínea , Hemodinâmica/fisiologia , Lentes Intraoculares , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Oftalmológicos , Período Pós-Operatório , Estudos Prospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...