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The Pediatric Heart Network's Fontan Udenafil Exercise Longitudinal (FUEL) Trial (Mezzion Pharma Co. Ltd., NCT02741115) demonstrated improvements in some measures of exercise capacity and in the myocardial performance index following 6 months of treatment with udenafil (87.5 mg twice daily). In this post hoc analysis, we evaluate whether subgroups within the population experienced a differential effect on exercise performance in response to treatment. The effect of udenafil on exercise was evaluated within subgroups defined by baseline characteristics, including peak oxygen consumption (VO2), serum brain-type natriuretic peptide level, weight, race, gender, and ventricular morphology. Differences among subgroups were evaluated using ANCOVA modeling with fixed factors for treatment arm and subgroup and the interaction between treatment arm and subgroup. Within-subgroup analyses demonstrated trends toward quantitative improvements in peak VO2, work rate at the ventilatory anaerobic threshold (VAT), VO2 at VAT, and ventilatory efficiency (VE/VCO2) for those randomized to udenafil compared to placebo in nearly all subgroups. There was no identified differential response to udenafil based on baseline peak VO2, baseline BNP level, weight, race and ethnicity, gender, or ventricular morphology, although participants in the lowest tertile of baseline peak VO2 trended toward larger improvements. The absence of a differential response across subgroups in response to treatment with udenafil suggests that the treatment benefit may not be restricted to specific sub-populations. Further work is warranted to confirm the potential benefit of udenafil and to evaluate the long-term tolerability and safety of treatment and to determine the impact of udenafil on the development of other morbidities related to the Fontan circulation.Trial Registration NCT0274115.
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Consumo de Oxígeno , Sulfonamidas , Humanos , Niño , Sulfonamidas/uso terapéutico , Ejercicio Físico , Pirimidinas/uso terapéutico , Prueba de Esfuerzo , Tolerancia al EjercicioRESUMEN
AIM: To assess the prognostic value of negative interim combined 2-[(18)F]-fluoro-2-deoxy-d-glucose ((18)F-FDG) positron-emission tomography/computed tomography (PET/CT) in patients with diffuse large B-cell lymphoma (DLBCL). MATERIALS AND METHODS: Ninety-two patients with histologically proven DLBCL were enrolled. All of the patients underwent (18)F-FDG PET/CT at diagnosis, and interim PET/CT after the second cycle of chemotherapy with rituximab, cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisolone (R-CHOP). Negative interim PET/CT was defined as the disappearance of all abnormal (18)F-FDG uptake compared to the pretreatment PET/CT image, as determined by visual assessment. The clinical outcome of patients was estimated as progression-free survival (PFS), and the prognostic significance of clinicopathological and imaging parameters were assessed using the Cox proportional hazards model. RESULTS: Thirty-six patients (39.1%) showed lymphoma progression within a median follow-up of 30.8 months. According to univariate analysis, Ann Arbor stage, serum lactate dehydrogenase level, Eastern Cooperative Oncology Group scale, International Prognostic Index (IPI) score, and maximum standardised uptake values on initial PET/CT were significant prognostic factors for PFS (all p<0.05). Among these parameters, only the IPI score was an independent predictor for PFS (p=0.044). Survival of patients with a high IPI score (≥3) was poorer than those with a low IPI score (0-2; p<0.001). CONCLUSION: Despite a negative interim (18)F-FDG PET/CT, approximately 39% of DLBCL patients showed progression during follow-up. Although the negative PET/CT was obtained during chemotherapy, it is important to closely follow-up patients, especially those with a high IPI score.
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Linfoma de Células B Grandes Difuso/diagnóstico por imagen , Imagen Multimodal , Adolescente , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Progresión de la Enfermedad , Femenino , Fluorodesoxiglucosa F18/farmacocinética , Humanos , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Tomografía de Emisión de Positrones , Pronóstico , Radiofármacos/farmacocinética , Tomografía Computarizada por Rayos XRESUMEN
The purpose of this study was to determine the influence of insurance status on treatment and outcomes in oral cavity cancer. Patients were identified in the National Cancer Database (NCDB). Data were collected and analyzed using χ2 tests, Kaplan-Meier methods, and multivariable Cox regression models. Those uninsured or on Medicaid were more likely to be younger (P<0.001), minority race (P<0.001), have a lower median household income (P<0.001), lower educational attainment (P<0.001), not undergo primary resection (P<0.001), present with higher T (P<0.001),N (P<0.001), and M (P<0.001) stage of disease, and have a higher tumor grade (P<0.001). On univariate analysis, those with private insurance had significantly better overall survival than those uninsured (hazard ratio (HR) 1.481), under Medicaid (HR 2.006), or on Medicare (HR 1.921). On multivariable Cox regression analysis, insurance status remained an independent prognosticator even after accounting for multiple demographic, socioeconomic, treatment, and clinicopathological factors. These data suggest that insurance status is associated with treatment and outcomes in patients with oral cavity cancer. Being uninsured or on Medicaid was found to be associated with a higher risk of a poorer prognosis when compared to private insurance, and the data suggest the need to expand comprehensive medical coverage and optimize access to adequate medical care in vulnerable patient populations.
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Carcinoma de Células Escamosas/terapia , Cobertura del Seguro , Neoplasias de la Boca/terapia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Demografía , Femenino , Humanos , Masculino , Medicaid/estadística & datos numéricos , Pacientes no Asegurados/estadística & datos numéricos , Medicare/estadística & datos numéricos , Persona de Mediana Edad , Análisis de Supervivencia , Resultado del Tratamiento , Estados UnidosRESUMEN
Parkinson's disease dementia (PDD) and dementia with Lewy bodies (DLB) share many similar aspects, and making a clinical diagnosis of one disorder over the other relies heavily on an arbitrary criterion, so-called 1-year rule. This study was designed to search for any difference of metabolic patterns in these two disorders using F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) images. We enrolled 16 patients with PD, 13 patients with PDD, and seven patients with DLB. FDG PET was performed, and images were reconstructed by iterative reconstruction using the computed tomography (CT) images, and were normalized to a standard template. Statistical comparison between groups were performed on a voxel-by-voxel basis using t-statistics (two-sample t-test). Compared with the patients with PD, both PDD and DLB patients showed similar patterns of decreased metabolism in bilateral inferior and medial frontal lobes, and right parietal lobe (P(uncorrected) < 0.001). In a direct comparison, DLB patients had significant metabolic decrease (p(uncorrected) < 0.005) in the anterior cingulate compared with those with PDD. These findings support the concept that PDD and DLB have similar underlying neurobiological characteristics, and that they can be regarded as a spectrum of Lewy body disorders.
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Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/metabolismo , Demencia/metabolismo , Glucosa/metabolismo , Enfermedad por Cuerpos de Lewy/diagnóstico por imagen , Enfermedad por Cuerpos de Lewy/metabolismo , Enfermedad de Parkinson/diagnóstico por imagen , Enfermedad de Parkinson/metabolismo , Anciano , Anciano de 80 o más Años , Mapeo Encefálico , Corteza Cerebral/fisiopatología , Demencia/diagnóstico por imagen , Demencia/etiología , Diagnóstico Diferencial , Femenino , Fluorodesoxiglucosa F18 , Lateralidad Funcional , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Enfermedad de Parkinson/fisiopatología , Tomografía de Emisión de Positrones , Valor Predictivo de las Pruebas , Sensibilidad y EspecificidadRESUMEN
nur77, an immediate-early gene that encodes an orphan nuclear receptor, is rapidly and transiently induced by nerve growth factor (NGF) stimulation or membrane depolarization in the rat pheochromocytoma-derived cell line PC12. The Nur77 protein can act as a potent transcription activator and may function to regulate the expression of downstream genes in response to extracellular stimuli. We show here that activation of nur77 by NGF treatment and membrane depolarization is signalled through distinct pathways. These distinct signals appear to converge on the same transcription factors acting on the same promoter elements. We show that nur77 activation by both processes requires two cis-acting AP1-like elements, NAP1 and NAP2, which contain the core sequence TGCGTCA centered at 67 and 38 nucleotides upstream of the transcription start site. The NAP elements can confer inducibility by NGF and membrane depolarization on an otherwise unresponsive heterologous promoter. We identified JunD as a key mediator of nur77 activation by reason of the following observations. (i) JunD, but not CREB or other members of the Fos/Jun family, is a component of NAP binding activity in PC12 cell nuclear extracts. (ii) JunD, but not other Fos/Jun family members, specifically transactivates the nur77 promoter through the NAP elements (iii) A dominant-negative mutant of JunD effectively abolishes the activation of nur77 by either NGF treatment or membrane depolarization. These data draw a contrast between the regulation of nur77 with that of c-fos, in which the sequence requirements for activation by NGF treatment and membrane depolarization appear separable, and CREB appears to play a role in activation by both NGF and membrane depolarization.
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Proteínas de Unión al ADN/genética , Genes Inmediatos-Precoces , Factores de Crecimiento Nervioso/farmacología , Proteínas Proto-Oncogénicas c-jun/fisiología , Factores de Transcripción/genética , Animales , Secuencia de Bases , Sitios de Unión , Colforsina/farmacología , Regulación de la Expresión Génica , Potenciales de la Membrana , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Miembro 1 del Grupo A de la Subfamilia 4 de Receptores Nucleares , Oligodesoxirribonucleótidos/química , Células PC12 , Cloruro de Potasio/farmacología , Regiones Promotoras Genéticas , Ratas , Receptores Citoplasmáticos y Nucleares , Receptores de Esteroides , Transducción de Señal , Transcripción Genética , Activación TranscripcionalRESUMEN
The N-end rule relates the in vivo half-life of a protein to the identity of its N-terminal residue. N-terminal asparagine and glutamine are tertiary destabilizing residues, in that they are enzymatically deamidated to yield secondary destabilizing residues aspartate and glutamate, which are conjugated to arginine, a primary destabilizing residue. N-terminal arginine of a substrate protein is bound by the Ubr1-encoded E3alpha, the E3 component of the ubiquitin-proteasome-dependent N-end rule pathway. We describe the construction and analysis of mouse strains lacking the asparagine-specific N-terminal amidase (Nt(N)-amidase), encoded by the Ntan1 gene. In wild-type embryos, Ntan1 was strongly expressed in the branchial arches and in the tail and limb buds. The Ntan1(-/-) mouse strains lacked the Nt(N)-amidase activity but retained glutamine-specific Nt(Q)-amidase, indicating that the two enzymes are encoded by different genes. Among the normally short-lived N-end rule substrates, only those bearing N-terminal asparagine became long-lived in Ntan1(-/-) fibroblasts. The Ntan1(-/-) mice were fertile and outwardly normal but differed from their congenic wild-type counterparts in spontaneous activity, spatial memory, and a socially conditioned exploratory phenotype that has not been previously described with other mouse strains.
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Amidohidrolasas/fisiología , Asparagina , Conducta Animal , Memoria , Amidohidrolasas/genética , Animales , Reacción de Fuga , Femenino , Expresión Génica , Líquido Intracelular/metabolismo , Aprendizaje , Masculino , Ratones , Ratones Endogámicos C57BL , Desempeño Psicomotor , Conducta SocialRESUMEN
We report the cDNA sequence and genomic structure of gly96, an immediate early gene inducible by serum growth factors in mouse fibroblasts. It encodes a 153-amino acid protein that does not share significant sequence similarity with any known protein. In the adult mouse, gly96 is expressed predominantly in the lung, testes and the uterus. We have identified the Gly96 protein in Balb/c 3T3 cells using affinity-purified antibodies recognizing the Gly96 polypeptide. We show that Gly96 is glycosylated and has a short half-life in serum stimulated fibroblasts.
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ADN/química , Expresión Génica , Glicoproteínas/genética , Sustancias de Crecimiento/farmacología , Células 3T3 , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Regulación de la Expresión Génica/efectos de los fármacos , Glicoproteínas/análisis , Glicoproteínas/metabolismo , Semivida , Ratones , Datos de Secuencia Molecular , Acetato de Tetradecanoilforbol/farmacologíaRESUMEN
Xenotransplantation offers a solution to the shortage of available organs for transplantation, and the pig represents an ideal source of such organs. However, porcine endogenous retrovirus (PERV), whose genome is integrated in pigs, has been suggested to pose a potential risk of xenotransmission. Expression of PERVs in different organs of pigs was carefully measured at DNA, mRNA, and protein levels, providing information valuable for the application of pig organs in xenotransplantation. An analysis of PERV DNA showed that a very similar number of PERV copies was present in the genome of all organs, whereas mRNA and protein levels of PERV varied depending on the organ, with kidney, liver, and spleen expressing high levels of both mRNA and protein. In contrast, mRNA and protein levels were dissimilar in the lung and brain, where mRNA levels were low but protein levels were high. This discrepancy indicates that mRNA levels are not always reflected in protein expression. In addition, the difference between mRNA and protein highlights the importance of choosing the proper analysis method for diagnosing viral infection. In summary, this study provides insight into the distribution of PERV in various organs at the DNA, mRNA, and protein levels, and also informs the proper selection of tissues or organs for future clinical xenotransplantation.
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Retrovirus Endógenos/aislamiento & purificación , Trasplante de Órganos , ARN Mensajero/genética , Proteínas Virales/genética , Animales , Encéfalo/virología , Modelos Animales de Enfermedad , Corazón/virología , Hígado/virología , Pulmón/virología , Músculo Esquelético/virología , República de Corea , Bazo/virología , Sus scrofa , Porcinos , Trasplante Heterólogo , Proteínas Virales/biosíntesisRESUMEN
Among 236 non-insulin-dependent diabetics with clinically suspected coronary artery disease, the rate of thallium-201 myocardial perfusion defects was significantly higher in subjects with (40.6%) than without (22.1%) diabetic retinopathy. Retinopathy was associated with a higher risk of perfusion defects in subjects with cardiac and noncardiac chest pain, and may thus be a useful marker for selecting patients in whom thallium scintigraphy screening is warranted.
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Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/etiología , Diabetes Mellitus Tipo 2/complicaciones , Retinopatía Diabética/complicaciones , Distribución de Chi-Cuadrado , Angiografía Coronaria , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Factores de Riesgo , Radioisótopos de Talio , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
UNLABELLED: The aim of this study was to compare the diagnostic utility of visual versus semi-quantitative analysis of salivary gland scintigraphy in the diagnosis of Sjögren's syndrome (SS). PATIENTS, METHODS: 99mTc-pertechnetate salivary gland scintigraphy was performed in 145 patients (133 women, 12 men) with clinically suspicious SS. The images were interpreted with visual and semiquantitative methods and the diagnostic performances for SS were compared using uptake and excretory functional parameters. RESULTS: In total, 76 patients (52.4%) were finally diagnosed with SS. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of visual analysis for the diagnosis of SS were 88.2%, 48.6%, 65.1%, 79.1%, and 69.2%, respectively. Semiquantitative values, the area under the ROC curve for uptake ratio and percentage excretion in the right salivary glands were signiï¬cantly greater than 0.5 (p < 0.05). However, the percentage excretion in the left salivary glands did not show a statistically significant diagnostic ability for SS. The diagnostic ability of visual assessment was greater than that of the semiquantitative method in terms of evaluating uptake and excretory function in the submandibular glands. CONCLUSION: Visual analysis of salivary gland scintigraphy showed greater diagnostic utility than semiquantitative assessment in the diagnosis of SS, especially in the submandibular glands.
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Interpretación de Imagen Asistida por Computador/métodos , Tomografía de Emisión de Positrones/métodos , Glándulas Salivales/diagnóstico por imagen , Síndrome de Sjögren/diagnóstico por imagen , Pertecnetato de Sodio Tc 99m , Xerostomía/diagnóstico por imagen , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Radiofármacos , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y Especificidad , Adulto JovenRESUMEN
UNLABELLED: The aim of this study was to evaluate the diagnostic abilities of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography(PET/CT) compared with those of ultrasonography and magnetic resonance imaging (MRI) for axillary lymph node staging in breast cancer patients. PATIENTS, METHODS: Preoperative 18F-FDG PET/non-contrast CT, ultrasonography and MRI were performed in 215 women with breast cancer. Axillary lymph node dissection was performed in all patients and the diagnostic performance of each modality was evaluated using histopathologic assessments as the reference standard. ROC curves were compared to evaluate the diagnostic ability of several imaging modalities (i. e., ultrasonography, MRI and 18F-FDG PET/CT). RESULTS: In total, 132 patients (61.4%) had axillary lymph node metastasis. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for the detection of axillary lymph node metastasis were 72.3%, 77.3%, 66.7%, 81.6%, 75.3% for ultrasonography, 67.5%, 78.0%, 65.9%, 79.2%, 74.0% for MRI, and 62.7%, 88.6%, 77.6%, 79.1%, 78.6% for 18F-FDG PET/CT, respectively. There was no significant difference in diagnostic ability among the imaging modalities (i.e., ultrasonography, MRI and 18F-FDG PET/CT). The diagnostic ability of 18F-FDG PET/CT was significantly improved by combination with MRI (p = 0.0002) or ultrasonography (p < 0.0001). The combination of 18F-FDG PET/CT with ultrasonography had a similar diagnostic ability to that of all three modalities combined (18F-FDG PET/CT+ultrasonography+MRI, p = 0.05). CONCLUSION: The diagnostic performance of 18F-FDG PET/CT for detection of axillary node metastasis was not significantly different from that of ultrasonography or MRI in breast cancer patients. Combining 18F-FDG PET/CT with ultrasonography or MRI could improve the diagnostic performance compared to 18F-FDG PET/CT alone.
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Neoplasias de la Mama/diagnóstico , Carcinoma/diagnóstico , Carcinoma/secundario , Imagen por Resonancia Magnética/métodos , Tomografía de Emisión de Positrones/métodos , Tomografía Computarizada por Rayos X/métodos , Ultrasonografía Mamaria/métodos , Adulto , Anciano , Anciano de 80 o más Años , Axila , Femenino , Fluorodesoxiglucosa F18 , Humanos , Ganglios Linfáticos/patología , Metástasis Linfática , Masculino , Persona de Mediana Edad , Imagen Multimodal/métodos , Estadificación de Neoplasias , Radiofármacos , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
AIM: This study was performed to evaluate the effects of intravenously transplanted rat bone-marrow derived mesenchymal stem cells (rBMSCs) in an acute brain trauma model using serial 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) in rat models. ANIMALS, METHODS: Trauma models were made using a controlled cortical impact injury device. The stem cell treatment group was treated with intravenous injections of BMSCs, and models without stem cell therapy comprised the control group. Serial 18F-FDG PET images were obtained 1, 7, 14, 21, and 28 days after trauma. The difference in 18F-FDG uptake between day 1 and each time point after trauma was analyzed with SPM2 (uncorrected p < 0.005). RESULTS: The stem cell treatment group demonstrated significantly higher 18F-FDG uptake in the right parietal region at 14 days after trauma than at 1 day after trauma. An increase in glucose metabolism in the right parietal cortex appeared on days 21 and 28 after trauma in the group without stem cell treatment. The 18F-FDG uptake in the brain was improved over a broader area, including the right parietal and right primary somatosensory cortex, on days 21 and 28 after trauma in the stem cell treatment group compared with the group without stem cell treatment. CONCLUSION: BMSC therapy in trauma models led to improved glucose metabolism. This result might support the therapeutic effect of stem cells in brain trauma.
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Trasplante de Médula Ósea/métodos , Lesiones Encefálicas/metabolismo , Lesiones Encefálicas/cirugía , Encéfalo/metabolismo , Fluorodesoxiglucosa F18/farmacocinética , Trasplante de Células Madre Mesenquimatosas/métodos , Animales , Encéfalo/diagnóstico por imagen , Encéfalo/cirugía , Lesiones Encefálicas/diagnóstico por imagen , Modelos Animales de Enfermedad , Humanos , Cintigrafía , Radiofármacos/farmacocinética , Ratas , Ratas Sprague-Dawley , Resultado del TratamientoRESUMEN
The purpose of this study was to determine whether the addition of small quantities of minor lecithin components (phosphatidylinositol, phosphatidic acid, lysophosphatidylethanolamine, and cholesterol) and Pluronic F68 to lecithin could improve the stability of lecithin-stabilized perfluorocarbon emulsions. Attempts were made to correlate emulsion stability with interfacial properties (tension and charge). Dynamic interfacial tension was determined using a Teflon Wilhelmy plate method [reported previously (1)]. Emulsions were prepared by microfluidization. Microelectrophoresis was used to measure emulsion droplet charge, and photon correlation spectroscopy and Coulter analysis were used to determine emulsion stability as a function of droplet size. Thermal kinetic accelerated stability testing was conducted. Various droplet size parameters were used to compare emulsion stabilities, and an overall stability ranking, based on these parameters, was obtained for each emulsion. Small quantities of additives altered emulsion stability and these data were correlated with interfacial properties and initial droplet diameters. The addition of cholesterol to lecithin resulted in the most stable perfluorocarbon emulsion.
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Excipientes/química , Fluorocarburos , Fosfatidilcolinas/química , Fenómenos Químicos , Química Física , Colesterol , Estabilidad de Medicamentos , Emulsiones , Poloxaleno , Propiedades de Superficie , Tensoactivos , TemperaturaRESUMEN
Paraxial mesoderm in vertebrates gives rise to all trunk and limb skeletal muscles, the trunk skeleton, and portions of the trunk dermis and vasculature. We show here that germline deletion of mouse pMesogenin1, a bHLH class gene specifically expressed in developmentally immature unsegmented paraxial mesoderm, causes complete failure of somite formation and segmentation of the body trunk and tail. At the molecular level, the phenotype features dramatic loss of expression within the presomitic mesoderm of Notch/Delta pathway components and oscillating somitic clock genes that are thought to control segmentation and somitogenesis. Subsequent patterning and specification steps for paraxial mesoderm also fail, leading to a complete absence of all trunk paraxial mesoderm derivatives, which include skeletal muscle, vertebrae, and ribs. We infer that pMesogenin1 is an essential upstream regulator of trunk paraxial mesoderm development and segmentation.
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Proteínas Fetales , Glicosiltransferasas , Mesodermo/patología , Mesodermo/fisiología , Proteínas de Saccharomyces cerevisiae , Factores de Transcripción/genética , Anomalías Múltiples , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Diferenciación Celular/genética , Desarrollo Embrionario y Fetal/genética , Femenino , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulación del Desarrollo de la Expresión Génica , Secuencias Hélice-Asa-Hélice , Homocigoto , Masculino , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos , Ratones Mutantes , Proteínas/genética , Proteínas/metabolismo , Receptores Notch , Recombinación Genética , Transducción de Señal , Proteínas de Dominio T Box/genética , Proteínas de Dominio T Box/metabolismo , Cola (estructura animal)/anomalías , Factores de Transcripción/metabolismoRESUMEN
nur77 is an immediate-early gene inducible by nerve growth factor or membrane depolarization in the rat pheochromocytoma cell line PC12 and by serum growth factors in fibroblasts. The nur77-encoded protein is a member of the steroid/thyroid hormone receptor superfamily and can act as a potent transcription activator. The induction of nur77 in PC12 cells is rapid and transient, with kinetics similar to those of the c-fos protooncogene. Induction does not require de novo protein synthesis. Whereas transcriptional activation of c-fos by nerve growth factor in PC12 cells requires a 20-base pair serum response element in its promoter, there is no such sequence in the nur77 promoter. To understand the mechanism for the activation of nur77, we have analyzed the inducibility of a series of transfected nur77 minigenes using an S1 nuclease protection assay. We identified the sequence 22-86 nucleotides upstream of the transcription start site as necessary and sufficient for nur77 induction by nerve growth factor and membrane depolarization in PC12 cells. Sequences farther upstream enhance the induction. Analysis of base substitution mutations allowed us to identify three sequence elements within this region that are essential for induction. These sequence elements include two copies of an AP1-like element and a GC-rich sequence. Unlike transcriptional activation of c-fos, the sequence requirements for the activation of nur77 by nerve growth factor and membrane depolarization cannot be readily separated. Taken together, our data suggest that activation of nur77 and c-fos by nerve growth factor occurs through different mechanisms in PC12 cells.
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Proteínas de Unión al ADN/genética , Factores de Crecimiento Nervioso/farmacología , Cloruro de Potasio/farmacología , Factores de Transcripción/genética , Transcripción Genética , Animales , Secuencia de Bases , ADN , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica , Potenciales de la Membrana , Datos de Secuencia Molecular , Mutagénesis , Miembro 1 del Grupo A de la Subfamilia 4 de Receptores Nucleares , Células PC12 , Regiones Promotoras Genéticas , Receptores Citoplasmáticos y Nucleares , Receptores de Esteroides , Factores de Transcripción/metabolismo , Transcripción Genética/efectos de los fármacosRESUMEN
A novel method of determination of protein stability is described, which involves interfacial shear rheology of adsorbed protein layers. This technique provides information on the structural-mechanical properties of the adsorbed protein layers which can be related to: the rate of interfacial adsorption, interfacial interactions, and conformational changes in the adsorbed layers. The interfacial shear rheology of the blood proteins, bovine serum albumin and human immunoglobulin G was investigated. The air/aqueous and oil/aqueous interfaces were studied and the interfacial rheological activity of BSA was shown to be similar at three hydrophobic interfaces: air, squalene and mineral oil. The kinetics of interfacial film formation was shown to be time dependent, and aging effects were detected in both interfacial and bulk molecules. The absolute interfacial elasticity values decreased as the temperature increased. The protein solutions exhibited no interfacial rheological activity in the presence of the small surfactant molecules, Tween 80 and lecithin, under the conditions studied.
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Inmunoglobulina G/química , Albúmina Sérica Bovina/química , Fenómenos Químicos , Química Física , Elasticidad , Humanos , Conformación Proteica , Desnaturalización Proteica , Reología , Tecnología FarmacéuticaRESUMEN
Interfacial adsorption of proteins can be studied using microscopic surface analysis techniques, and by physical techniques such as interfacial tension measurement. A novel method of surface analysis of adsorbed protein layers is described, which involves interfacial shear rheology of aqueous solutions of proteins. This technique provides information on the structural-mechanical properties of the adsorbed layers which may be related to: the rate of interfacial adsorption, interfacial interactions, and conformational changes in the adsorbed layers. The interfacial shear rheology of aqueous solutions of the blood proteins, bovine serum albumin and human immunoglobulin G was investigated at the air/aqueous interface. The effects of bulk concentration (0.1 to 4.0% w/v) and pH (3 to 8) were investigated, both interfacial viscosity and elasticity values are reported.
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Proteínas Sanguíneas/farmacocinética , Reología/métodos , Adsorción , Elasticidad , Electroforesis/métodos , Humanos , Concentración de Iones de Hidrógeno , Peso Molecular , Propiedades de Superficie , ViscosidadRESUMEN
A new bHLH gene from mouse that we call pMesogenin1 (referring to paraxial mesoderm-specific expression and regulatory capacities) and its candidate ortholog from Xenopus were isolated and studied comparatively. In both organisms the gene is specifically expressed in unsegmented paraxial mesoderm and its immediate progenitors. A striking feature of pMesogenin1 expression is that it terminates abruptly in presumptive somites (somitomeres). Somitomeres rostral to the pMesogenin1 domain strongly upregulate expression of pMesogenin's closest known paralogs, MesP1 and MesP2 (Thylacine1/2 in Xenopus). Subsequently, the most rostral somitomere becomes a new somite and expression of MesP1/2 is sharply downregulated before this transition. Thus, expression patterns of these bHLH genes, together with that of an additional bHLH gene in the mouse, Paraxis, collectively define discrete but highly dynamic prepatterned subdomains of the paraxial mesoderm. In functional assays, we show that pMesogenin1 from either mouse or frog can efficiently drive nonmesodermal cells to assume a phenotype with molecular and cellular characteristics of early paraxial mesoderm. Among genes induced by added pMesogenin1 is Xwnt-8, a signaling factor that induces a similar repertoire of marker genes and a similar cellular phenotype. Additional target genes induced by pMesogenin1 are ESR4/5, regulators known to play a significant role in segmentation of paraxial mesoderm (W. C. Jen et al., 1999, Genes Dev. 13, 1486-1499). pMesogenin1 differs from other known mesoderm-inducing transcription factors because it does not also activate a dorsal (future axial) mesoderm phenotype, suggesting that pMesogenin1 is involved in specifying paraxial mesoderm. In the context of the intact frog embryo, ectopic pMesogenin1 also actively suppressed axial mesoderm markers and disrupted normal formation of notochord. In addition, we found evidence for cross-regulatory interactions between pMesogenin1 and T-box transcription factors, a family of genes normally expressed in a broader pattern and known to induce multiple types of mesoderm. Based on our results and results from prior studies of related bHLH genes, we propose that pMesogenin1 and its closest known relatives, MesP1/2 (in mouse) and Thylacine1/2 (in Xenopus), comprise a bHLH subfamily devoted to formation and segmentation of paraxial mesoderm.
Asunto(s)
Proteínas de Unión al ADN/genética , Desarrollo Embrionario y Fetal , Regulación del Desarrollo de la Expresión Génica , Mesodermo/fisiología , Factores de Transcripción/genética , Secuencia de Aminoácidos , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Tipificación del Cuerpo , Biblioteca de Genes , Secuencias Hélice-Asa-Hélice , Hibridación in Situ , Ratones , Ratones Endogámicos , Datos de Secuencia Molecular , Fenotipo , Filogenia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Transducción de Señal , Factores de Transcripción/química , Xenopus laevisRESUMEN
Pituitary tissue contains phenol sulfotransferase (PST), the enzyme that catalyzes the sulfate conjugation of monoamine neurotransmitters. We carried out these studies with pituitaries obtained 21.3 +/- 3.0 h postmortem (mean +/- SEM; n = 21) to determine whether the biochemical properties and variations in levels of human pituitary PST activities were similar to those of PST in platelets from control subjects. PST in the human platelet has been studied thoroughly because of the possibility that platelet PST might reflect levels of PST activity in other tissues such as the pituitary and brain. Our results demonstrated 2 forms of the pituitary enzyme that were similar to the thermostable (TS) and thermolabile (TL) forms of platelet PST with regard to assay conditions, pH optima, Km values for multiple substrates, responses to 2,6-dichloro-4-nitrophenol (DCNP), and thermal stability properties. Pituitary samples also were obtained at autopsy 6.3 +/- 0.33 h (mean +/- SEM; n = 3) after death to determine the effects of storage at 4 degrees C on PST activities. After storage for 6-18 h, 83-99.6% of the TS PST activity remained and 44-66.9% of the TL PST activity remained. Pituitary TS PST activity in samples obtained within 12.1 +/- 3.25 h after death was 121.0 +/- 49.1 units/mg protein (mean +/- SEM; n = 7) with a range from 9.7 to 367.6. TL PST activity was 35.6 +/- 11.6 units/mg protein (mean +/- SEM; n = 6) with a range from 6.1 to 80.7. Wide variations of both enzyme activities were also present in 3 pituitary tumor samples.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Hipófisis/enzimología , Sulfurtransferasas/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Arilsulfotransferasa , Frío , Femenino , Humanos , Concentración de Iones de Hidrógeno , Masculino , Persona de Mediana Edad , Preservación de Órganos , Cambios Post Mortem , Temperatura , Factores de TiempoRESUMEN
The freezing behavior of gold nanoclusters was studied by employing molecular dynamics simulations based on the semiempirical embedded-atom method. Investigations of the gold nanoclusters revealed that, just after freezing, ordered nanosurfaces with a fivefold symmetry were formed with interior atoms remaining in the disordered state. Further lowering of temperatures induced nanocrystallization of the interior atoms that proceeded from the surface towards the core region, finally leading to an icosahedral structure. These dynamic processes explain why the icosahedral cluster structure is dominantly formed in spite of its energetic metastability.