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1.
Geburtshilfe Frauenheilkd ; 76(11): 1186-1188, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27904169

RESUMO

The "lean" umbilical cord (also known as thin-cord syndrome) is a comparatively rare anomaly of the umbilical cord, which has seldom been described in the medical literature. We report on a 35-year-old women who presented to us at 29 + 4 weeks gestation with vaginal bleeding and cervical incompetence subsequently complicated not only by premature rupture of membranes but also acute placental insufficiency requiring emergency caesarean section under general anaesthesia at 31 + 2 weeks gestation. At surgery no obvious cause for the acute placental insufficiency - such as placental abruption, cord prolapse or true knot of the umbilical cord - was found. Other possible causes such as vasa praevia or placenta praevia had previously been excluded sonographically on admission for vaginal bleeding. The only notable intraoperative finding was a macroscopically extremely thin umbilical cord.

2.
Geburtshilfe Frauenheilkd ; 76(7): 819-822, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27453586

RESUMO

Twin pregnancy consisting of one fetus and one complete mole (CMCF, complete hydatidiform mole and a coexistent fetus) is an obstetric rarity with an incidence of 1/22 000 to 1/100 000 pregnancies. Associated risks include prematurity, intrauterine death, vaginal bleeding, preeclampsia, hyperthyroidism, theca lutein cysts, uterine rupture and the development of malignant neoplasia in the form of a trophoblastic tumour (GTD, persistent gestational trophoblastic disease), which is thought to be the most common complication. We report the case of a 33-year-old patient diagnosed with CMCF in the 15th week of pregnancy. After comprehensive counselling the patient chose to proceed with her pregnancy under close observation and prophylactic fetal lung maturation. We were able to extend the pregnancy to 32 weeks gestation when heavy vaginal bleeding forced a decision to deliver by caesarean section.

3.
J Perinatol ; 34(12): 941-4, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25421128

RESUMO

Chorioamniotic membrane separation (CMS) comprises cases of spontaneous and iatrogenic detachment between the amniotic and chorionic membranes, with various fetal outcomes due to possible complications, particularly the formation of constrictive amniotic bands and preterm rupture of membranes. In the absence of mandatory management standards conservative monitoring is the most reported approach. In the case we present here, close sonographic surveillance afforded us the opportunity to observe the process from CMS to amnion rupture with the formation of constrictive amniotic bands and threatened cord impairment via constrictive margins of the amniotic sac. Despite the complicated background of reduced membranous layers in ruptured CMS, we performed a successful fetoscopic intervention with band release at 24 weeks' gestation and the pregnancy was prolonged to 34 weeks under close monitoring.


Assuntos
Síndrome de Bandas Amnióticas/cirurgia , Complicações na Gravidez/cirurgia , Adulto , Âmnio/diagnóstico por imagem , Âmnio/patologia , Síndrome de Bandas Amnióticas/diagnóstico por imagem , Córion/diagnóstico por imagem , Córion/patologia , Feminino , Fetoscopia , Humanos , Gravidez , Complicações na Gravidez/diagnóstico por imagem , Segundo Trimestre da Gravidez , Ultrassonografia
4.
Br J Cancer ; 107(3): 422-8, 2012 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-22782342

RESUMO

BACKGROUND: Established prognostic factors are of limited value to predict long-term survival and benefit from metastasectomy in advanced melanoma. This study aimed to identify prognostic factors in patients with distant metastasis. METHODS: We analysed overall survival of 855 institutional melanoma patients with distant metastasis by bivariate Kaplan-Meier survival probabilities and multivariate Cox hazard regression analysis. RESULTS: Serum lactate dehydrogenases (LDH), S100B, the interval between initial diagnosis and occurrence of distant metastasis, the site of distant metastases, and the number of involved distant sites were significant independent prognostic factors in both bivariate and multivariate analyses. Visceral metastases other than lung (hazard ratio (HR) 1.8), elevated S100B (HR 1.7) and elevated LDH (HR 1.6) had the highest negative impact on survival. Complete metastasectomy was likewise an independent prognostic factor in multivariate analysis. This treatment was associated with favourable survival for patients with normal LDH and S100B values (5-year survival, 37.2%). CONCLUSION: The serum markers LDH and S100B were both found to be prognostic factors in melanoma patients with distant metastasis. Furthermore, complete metastasectomy had an independent favourable prognostic impact in particular for the patient subgroup with normal LDH and S100B values.


Assuntos
Biomarcadores Tumorais/sangue , Lactato Desidrogenases/sangue , Melanoma/sangue , Fatores de Crescimento Neural/sangue , Proteínas S100/sangue , Idoso , Estudos de Coortes , Feminino , Seguimentos , Humanos , Masculino , Melanoma/enzimologia , Melanoma/patologia , Melanoma/cirurgia , Metastasectomia/métodos , Pessoa de Meia-Idade , Análise Multivariada , Metástase Neoplásica , Prognóstico , Subunidade beta da Proteína Ligante de Cálcio S100 , Análise de Sobrevida
5.
Anal Bioanal Chem ; 404(1): 273-6, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22644155

RESUMO

Resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOF-MS) is a robust method for real-time analysis of monocyclic and polycyclic aromatic hydrocarbons in complex emissions. A mobile system has been developed which enables direct analysis on site. In this paper, we utilize a multicomponent calibration scheme based on the analytes' photo-ionisation cross-sections relative to a calibrated species. This allows semi-quantification of a great number of components by only calibrating one compound of choice, here toluene. The cross-sections were determined by injecting nebulised solutions of aromatic compounds into the TOF-MS ion source with the help of a HPLC pump. Then, REMPI-TOF-MS was implemented at various chassis dynamometers and test cells and the exhaust of the following vehicles and engines investigated: a compression ignition light-duty (LD) passenger car, a compression ignition LD van, two spark ignition LD passenger cars, 2 two-stroke mopeds, and a two-stroke engine of a string gas trimmer. The quantitative time profiles of benzene are shown. The results indicate that two-stroke engines are a significant source for toxic and cancerogenic compounds. Air pollution and health effects caused by gardening equipment might still be underestimated.

6.
Anal Chim Acta ; 717: 28-38, 2012 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-22304813

RESUMO

Two-stroke mopeds are a popular and convenient mean of transport in particular in the highly populated cities. These vehicles can emit potentially toxic gaseous and aerosol pollutants due to their engine technology. The legislative measurements of moped emissions are based on offline methods; however, the online characterization of gas and particulate phases offers great possibilities to understand aerosol formation mechanism and to adapt future emission standards. The purpose of this work was to study the emission behavior of two mopeds complying with different European emission standards (EURO-1 and EURO-2). A sophisticated set of online analyzers was applied to simultaneously monitor the gas phase and particulate phase of exhaust on a real time basis. The gaseous emission was analyzed with a high resolution Fourier transform infrared spectrometer (FTIR; nitrogen species) and a resonance-enhanced multiphoton ionization time-of-flight mass spectrometer (REMPI-ToF-MS; polycyclic aromatic hydrocarbons: PAH), whereas the particulate phase was chemically characterized by a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS; organic, nitrate and chloride aerosol) and a multiangle absorption photometer (MAAP; black carbon). The physical characterization of the aerosol was carried out with a condensation particle counter (CPC; particle number concentration) and a fast mobility particle sizer (FMPS; size distribution in real time). In order to extract underlying correlation between gas and solid emissions, principal component analysis was applied to the comprehensive online dataset. Multivariate analysis highlighted the considerable effect of the exhaust temperature on the particles and heavy PAH emissions. The results showed that the after-treatment used to comply with the latest EURO-2 emission standard may be responsible for the production of more potentially harmful particles compared to the EURO-1 moped emissions.

8.
Ultraschall Med ; 32 Suppl 2: E147-50, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21877319

RESUMO

PURPOSE: Novel aneuploidy screening has been suggested for measuring the yolk sac during very early pregnancy. However, in a pilot study the measured diameters differed up to 29 % from the overall average. The aim of this study was to analyze the impact of image magnification on yolk sac measurement. MATERIALS AND METHODS: From November 3, 2009 to July 28, 2010, 119 yolk sac measurements were performed. During each examination, each yolk sac was examined once with standard image magnification and once by live scan zoom. RESULTS: The measurement values were 5 % smaller in the standard image. The mean relative ratio (RR), median RR, and standard deviation (SD) were 0.951, 0.950, and 0.103 mm, respectively (95 % CI 0.744 to 1.158 mm). Regarding absolute differences, the mean, median, and standard deviation were -0.222 mm, -0.220 mm, and 0.473 mm, respectively, (95 % CI -1.169 to + 0.725 mm). With standard zoom (magnified images), the SD was 1.142 mm (1.099 mm). CONCLUSION: Five criteria should be regarded for optimal image settings: image magnification during live scan, optimal gain setting, enhanced gamma level, median section plane, and out-to-out caliper placement.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Ultrassonografia Pré-Natal/métodos , Saco Vitelino/diagnóstico por imagem , Aneuploidia , Aberrações Cromossômicas , Feminino , Humanos , Projetos Piloto , Gravidez , Primeiro Trimestre da Gravidez , Garantia da Qualidade dos Cuidados de Saúde/normas , Valores de Referência , Fatores de Risco , Sensibilidade e Especificidade
9.
Anal Chem ; 83(1): 67-76, 2011 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21126058

RESUMO

The European Commission recently established a novel test facility for heavy-duty vehicles to enhance more sustainable transport. The facility enables the study of energy efficiency of various fuels/scenarios as well as the chemical composition of evolved exhaust emissions. Sophisticated instrumentation for real-time analysis of the gas and particulate phases of exhaust has been implemented. Thereby, gas-phase characterization was carried out by a Fourier transform infrared spectrometer (FT-IR; carbonyls, nitrogen-containing species, small hydrocarbons) and a resonance-enhanced multiphoton ionization time-of-flight mass spectrometer (REMPI-TOFMS; monocyclic and polycyclic aromatic hydrocarbons). For analysis of the particulate phase, a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS; organic matter, chloride, nitrate), a condensation particle counter (CPC; particle number), and a multiangle absorption photometer (MAAP; black carbon) were applied. In this paper, the first application of the new facility in combination with the described instruments is presented, whereby a medium-size truck was investigated by applying different driving cycles. The goal was simultaneous chemical characterization of a great variety of gaseous compounds and particulate matter in exhaust on a real-time basis. The time-resolved data allowed new approaches to view the results; for example, emission factors were normalized to time-resolved consumption of fuel and were related to emission factors evolved during high speeds. Compounds could be identified that followed the fuel consumption, others showed very different behavior. In particular, engine cold start, engine ignition (unburned fuel), and high-speed events resulted in unique emission patterns.

10.
Fetal Diagn Ther ; 24(3): 291-5, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18818502

RESUMO

OBJECTIVE: First-trimester screening (FTS) has a trisomy 21 detection rate of about 90%. Despite profound training, the practically reached measurement quality of nuchal translucency (NT) is probably not optimal. This study investigated the impact of measurement errors on FTS. METHODS: The data on 10,116 combined FTSs were obtained in a multicenter study. Risk assessment was performed by the JOY software following the Nicolaides risk calculation principles. To investigate the impact of measurement errors, the NT values were artificially altered and the adjusted risks were recalculated. Test performance parameters were obtained and compared with the correct measurements. RESULTS: In this study 85 fetuses were genetically affected. The screening was wrongly inconspicuous in 12 cases and in 479 cases the FTS offered false-positive results. An assumed NT error of +/-0.1 mm already causes a highly significant change in the false-positive rate. A difference of -0.2 mm leads to a visible change in false negatives. DISCUSSION: This study demonstrates that even the smallest deviations will significantly affect the false-negative rate. The detection of really diseased fetuses is influenced at a -0.2-mm measurement error. Therefore the NT measurement has to be as precise as possible.


Assuntos
Medição da Translucência Nucal/métodos , Primeiro Trimestre da Gravidez , Adolescente , Adulto , Síndrome de Down/diagnóstico por imagem , Reações Falso-Negativas , Reações Falso-Positivas , Feminino , Humanos , Pessoa de Meia-Idade , Gravidez , Sensibilidade e Especificidade
12.
Endocrinology ; 133(1): 248-56, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8319574

RESUMO

Regulation of glucocorticoid receptor (GR) expression by its cognate ligand was examined in the glucocorticoid-sensitive human leukemic T-cell line 6TG1.1 and in the human B-cell line IM-9. In contrast to the decrease in GR mRNA seen in IM-9 cells after treatment with 1 microM dexamethasone for 16-18 h, treatment of 6TG1.1 cells resulted in an 8-fold increase in GR mRNA, as determined by Northern blot and RNase protection analysis, with a corresponding 3- to 4-fold increase in GR protein. Half-maximal induction of GR mRNA and protein in 6TG1.1 cells was observed between 10-100 nM dexamethasone, and inclusion of 1 microM RU 38486 completely blocked the effects of 100 nM dexamethasone, demonstrating that positive autoregulation of GR expression in 6TG1.1 cells is a receptor-mediated response. Positive autoregulation of GR expression was also observed in glucocorticoid-resistant CEM-C1 cells, which contain functional GR, but whose growth is unaffected by glucocorticoids. Thus, positive autoregulation is neither a consequence nor the sole cause of growth arrest. The degree of negative autoregulation in IM-9 cells and positive autoregulation in 6TG1.1 cells was unaffected by inhibition of protein synthesis with cycloheximide. Measurement of GR mRNA turnover in 6TG1.1 cells treated with actinomycin-D revealed a half-life of 2.5 h, which was unaffected by dexamethasone treatment. A similar half-life was determined in IM-9 cells and was also unaffected by steroid treatment. These results are consistent with the interpretation that glucocorticoid-mediated autoregulation of GR expression is a tissue-specific primary transcriptional response.


Assuntos
Linfócitos B/metabolismo , Regulação da Expressão Gênica , Receptores de Glucocorticoides/genética , Linfócitos T/metabolismo , Northern Blotting , Dactinomicina/farmacologia , Dexametasona/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Sondas RNA , RNA Mensageiro/metabolismo , Ribonucleases
14.
Biochemistry ; 30(46): 11140-6, 1991 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-1932034

RESUMO

The stability and DNA-binding properties of activation-labile (act1) human glucocorticoid receptors (hGRs) from the glucocorticoid-resistant mutant 3R7.6TG.4 were investigated. These receptors are able to bind reversibly associating ligands with normal affinity and specificity, but become unstable during attempted activation to the DNA binding form [Harmon et al. (1984) J. Steroid Biochem. 21, 227-236]. Affinity labeling and immunochemical analysis demonstrated that act1 receptors are not preferentially proteolyzed during attempted activation. In addition, analysis of binding to calf thymus DNA showed that after loss of ligand, act1 receptors retain the ability to bind to DNA nonspecifically. A 370 bp MMTV promoter fragment containing multiple GREs and an upstream 342 bp fragment lacking GRE sequences were used to assess the binding of act1 hGR to specific DNA sequences. Immunoadsorption of hGR-DNA complexes after incubation with 32P-end-labeled fragments showed that both normal and act1 hGR bound selectively to the GRE-containing fragment in an activation-dependent manner. Binding of both normal and act1 hGRs could be blocked with a synthetic oligonucleotide containing a perfect palindromic GRE, but not with an oligonucleotide in which the GRE was replaced by an ERE. Analogous results were obtained for normal and act1 hGR activated in the absence of ligand, or after incubation with the glucocorticoid antagonist RU 38486. These results suggest that sequence-specific binding of the hGR does not require the presence of bound ligand and suggest a role for the ligand in trans-activation of hormonally responsive genes.


Assuntos
Proteínas de Ligação a DNA/genética , Mutação , Receptores de Glucocorticoides/genética , Sequência de Bases , Linhagem Celular , DNA/química , Proteínas de Ligação a DNA/química , Humanos , Dados de Sequência Molecular , Receptores de Glucocorticoides/química , Ativação Transcricional
16.
Cancer Res ; 49(8 Suppl): 2238s-2243s, 1989 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-2702664

RESUMO

The possible role of posttranslational modification in glucocorticoid receptor regulation was investigated. Glucocorticoid receptor (GR), prepared from the human B-cell line IM-9 and affinity labeled with [3H]-dexamethasone 21-mesylate, was examined by a combination of one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis and high-resolution two-dimensional gel electrophoresis. Two-dimensional electrophoresis of immunopurified [3H]dexamethasone 21-mesylate-labeled GR revealed the presence of two isoelectric species (apparent pI approximately to 5.7, and 6.0-6.5). Both forms were present in preparations of unactivated receptor. After GR activation, the pI of neither isoform was altered, indicating that activation does not involve covalent charge modification of the steroid-binding protein. However, only the pI 6.0-6.5 isoform bound to DNA, suggesting that covalent charge modification of the GR can alter its ability to bind to DNA. Two-dimensional electrophoresis of tryptic and chymotryptic fragments showed that the charge heterogeneity responsible for the two GR isoforms is located in a Mr 26,500 tryptic fragment derived from the steroid-binding domain of the protein. In addition, analysis of [3H]dexamethasone 21-mesylate-labeled tryptic fragments suggests that the Mr 26,500 fragment corresponds to residues 499-743 of the human GR. These results demonstrate that posttranslational modification of the steroid-binding domain may regulate the ability of the protein to bind to DNA.


Assuntos
Receptores de Glucocorticoides/análise , Marcadores de Afinidade , Sequência de Aminoácidos , Dexametasona/metabolismo , Eletroforese em Gel de Poliacrilamida , Humanos , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Peso Molecular , Receptores de Glucocorticoides/fisiologia
17.
Mol Endocrinol ; 3(4): 734-43, 1989 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2725534

RESUMO

The molecular basis for the loss of steroid binding activity in receptorless (r-) glucocorticoid-resistant (dexr) mutants isolated from the glucocorticoid-sensitive (dexs) cell line CEM-C7 was investigated. Although there was little binding of the reversibly associating ligand [3H]dexamethasone in r- mutants, labeling with the covalent affinity ligand [3H] dexamethasone 21-mesylate revealed significant amounts of a 92 kilodalton human glucocorticoid receptor (hGR) protein. Immunoblots of hGR protein in r- and normal cells showed that r- mutants expressed approximately half the amount of immunoreactive hGR protein seen in dexs cells. Comparison of the genomic organization of the hGR genes in normal and mutant cells revealed no discernable differences in the structure, or dosage, indicating that the r- phenotype was not the result of gross deletion or rearrangement of the hGR genes. In addition, r- cells expressed the same 7 kilobase mRNA as normal cells. More importantly, the amount of hGR mRNA expressed in r- cells was never significantly less, and in some cases was greater than, that seen in normal cells, indicating that the decrease in immunoreactive hGR protein seen in r- cells is not the result of loss of hGR mRNA expression. Taken together with the known mutation rate of the hGR gene(s) in these cells, these results suggest that the hGR genes in dexs CEM-C7 cells are allelic and that dexs cells express both a normal hGR protein and one with an altered steroid binding site. Furthermore, they suggest that the r- phenotype is acquired as the result of mutation within the coding region of the originally functional allele, leading to loss of ligand binding and expression of immunoreactive product.


Assuntos
Regulação da Expressão Gênica , Leucemia/genética , Mutação , Receptores de Glucocorticoides/genética , Northern Blotting , Southern Blotting , Genótipo , Humanos , Ligantes , Fenótipo , RNA Mensageiro/análise , Células Tumorais Cultivadas
18.
J Steroid Biochem ; 31(3): 275-81, 1988 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-3419157

RESUMO

The relationship between glucocorticoid receptor subunit dissociation and activation was investigated by DEAE-cellulose and DNA-cellulose chromatography of monomeric and multimeric [3H]triamcinolone acetonide ([3H]TA)-labeled IM-9 cell glucocorticoid receptors. Multimeric (7-8 nm) and monomeric (5-6 nm) complexes were isolated by Sephacryl S-300 chromatography. Multimeric complexes did not bind to DNA-cellulose and eluted from DEAE-cellulose at a salt concentration (0.2 M KCl) characteristic of unactivated steroid-receptor complexes. Monomeric [3H]TA-receptor complexes eluted from DEAE-cellulose at a salt concentration (20 mM KCl) characteristic of activated steroid-receptor complexes. However, only half of these complexes bound to DNA-cellulose. This proportion could not be increased by heat treatment, addition of bovine serum albumin, or incubation with RNase A. Incubation of monomeric complexes with heat inactivated cytosol resulted in a 2-fold increase in DNA-cellulose binding. Unlike receptor dissociation, this increase was not inhibited by the presence of sodium molybdate. Fractionation of heat inactivated cytosol by Sephadex G-25 chromatography demonstrated that the activity responsible for the increased DNA binding of monomeric [3H]TA-receptor complexes was macromolecular. These results are consistent with a two-step model for glucocorticoid receptor activation, in which subunit dissociation is a necessary but insufficient condition for complete activation. They also indicate that conversion of the steroid-receptor complex to the low-salt eluting form is a reflection of receptor dissociation but not necessarily acquisition of DNA-binding activity.


Assuntos
Receptores de Glucocorticoides/metabolismo , Linhagem Celular , Cromatografia de Afinidade , Cromatografia DEAE-Celulose , Cromatografia em Gel , Humanos , Substâncias Macromoleculares , Modelos Teóricos , Receptores de Glucocorticoides/isolamento & purificação , Triancinolona Acetonida/metabolismo
19.
J Biol Chem ; 263(24): 12044-8, 1988 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-3261297

RESUMO

Regulation of glucocorticoid receptor (GR) protein and mRNA were examined in the human leukemic T-cell line CEM-C7. Unlike other cells in which GR regulation has been examined, the growth of these cells is inhibited by glucocorticoids, leading to cell death. Treatment of glucocorticoid-sensitive CEM-C7 cells with 1 microM dexamethasone for 18 h resulted in an increase in both cytoplasmic and nuclear GR protein, as determined by immunoblotting with anti-human GR antisera. Analysis of GR mRNA levels by Northern blotting revealed a corresponding increase in mRNA in steroid-treated cells. An increase in GR mRNA was detectable after as little as 3 h of treatment with dexamethasone, and GR mRNA concentration continued to increase for at least 18 h, well before the onset of growth arrest or cell death. GR mRNA concentration was not altered after dexamethasone treatment of the glucocorticoid-resistant mutant cell line ICR27TK.3, which lacks functional GR. Thus, the increase in GR seen in glucocorticoid-sensitive cells is a GR-mediated response. These results are in sharp contrast to the down-regulation of GR reported in other cells and tissues, and suggest that regulation of the GR by its cognate ligand may be tissue-specific.


Assuntos
Glucocorticoides/farmacologia , Leucemia Linfoide/metabolismo , Receptores de Glucocorticoides/metabolismo , Linfócitos T/metabolismo , Marcadores de Afinidade , Núcleo Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Citoplasma/metabolismo , Dexametasona/análogos & derivados , Dexametasona/metabolismo , Dexametasona/farmacologia , Eletroforese em Gel de Poliacrilamida , Humanos , Imunoensaio , Cinética , Mutação , RNA Mensageiro/biossíntese , Receptores de Glucocorticoides/genética , Linfócitos T/efeitos dos fármacos , Células Tumorais Cultivadas
20.
J Biol Chem ; 261(28): 13285-92, 1986 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-3759964

RESUMO

To determine if activation of the glucocorticoid receptor involves covalent charge modification of the steroid-binding protein, unactivated and activated IM-9 cell glucocorticoid receptors were examined by high resolution two-dimensional gel electrophoresis. As previously reported (Smith, A. C., and Harmon, J. M. (1985) Biochemistry 24, 4946-4951), two-dimensional electrophoresis of immunopurified, [3H]dexamethasone mesylate-labeled, steroid-binding protein from unactivated receptors resolves two 92-kDa isoforms (pI congruent to 5.7 and 6.0-6.5). After activation, the apparent pI of neither isoform was altered, indicating that there had been no covalent charge modification of the steroid-binding protein. Thus, the physicochemical changes observed after activation of the steroid receptor cannot be explained by dephosphorylation or other models which involve covalent charge modification of the steroid-binding protein. This conclusion was consistent with the observation that treatment of immunopurified, affinity-labeled receptors with calf intestine alkaline phosphatase did not alter the apparent pI values or distribution of the steroid-binding protein isoforms. However, chromatography of activated steroid-receptor complexes on DNA-cellulose revealed that only the more basic of the two steroid-binding protein isoforms bound to DNA. Therefore, the charge heterogeneity of the steroid-binding protein may be important in regulating the ability of the steroid-binding protein to interact with DNA.


Assuntos
Marcadores de Afinidade/metabolismo , Receptores de Glucocorticoides/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Bovinos , Linhagem Celular , Celulose/análogos & derivados , Celulose/metabolismo , Cromatografia em Gel , Cromatografia por Troca Iônica , DNA/análogos & derivados , DNA/metabolismo , Dexametasona/análogos & derivados , Dexametasona/farmacologia , Eletroforese em Gel de Poliacrilamida , Humanos , Ponto Isoelétrico , Triancinolona Acetonida/metabolismo
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