RESUMEN
Development of the anterior pituitary gland ultimately leads to the appearance of five distinct cell types that are defined by the trophic hormones which they produce, providing an instructive model system for elucidating the molecular mechanisms that underlie the determination of distinct cell phenotypes within an organ from a common precursor lineage. The recent identification of several homeodomain transcription factors expressed specifically in the anterior pituitary gland has revealed a transcriptional cascade orchestrating a developmental program that leads to the determination of the five mature cell types. Recent data from gene-targeting experiments in mice further imply that the execution of this program is dependent on inductive signals originating in the floor of the diencephalon.
Asunto(s)
Sistema Hipotálamo-Hipofisario/citología , Sistema Hipotálamo-Hipofisario/embriología , Sistema Hipófiso-Suprarrenal/citología , Sistema Hipófiso-Suprarrenal/embriología , Animales , Diferenciación Celular/genética , Regulación del Desarrollo de la Expresión Génica/fisiologíaRESUMEN
BACKGROUND AND PURPOSE: The aim of this study was to assess the clinical outcome of patients treated with the Penumbra system (PS) for acute ischemic stroke. A retrospective, monocentric matched-pair analysis in comparison with patients treated by intraarterial thrombolysis (IAT) with alteplase was designed for this purpose. METHODS: Twenty-two consecutive patients, (mean age 62), with acute ischemic stroke and National Institutes of Health Stroke Scale (NIHSS) scores ≥ 7 were treated with the PS. Twenty corresponding patients could be identified, treated with IAT. Matches were sought for initial NIHSS score and target vessels. Thrombolysis in myocardial infarction (TIMI) grades, mortality rates, NIHSS upon discharge, and modified Rankin scores (mRs) at 90 days were compared. RESULTS: A total of 32 vessels in 20 patients were treated in either arm of the study. Recanalization to TIMI 2/3 was successful in 25/32 (78%) of target vessels with the PS, and 17/32 (53%) of target vessels in the IAT group. Upon discharge, 2/20 patients treated with PS and 7/20 patients treated with IAT had a NIHSS score of 0 to 1 or an improvement greater or equal to 10-point on the NIHSS scale. All cause mortality at 90 days was 3/20 patients treated with PS, and 2/20 patients treated with IAT. Three out of twenty patients treated with PS and 7/20 patients treated with IAT had a mRS of ≤ 2 at 90 days. CONCLUSION: The Penumbra system is effective in re-opening occluded major arteries. Our data seems to indicate that not all patients benefit clinically from improved revascularization of occluded major arteries.
Asunto(s)
Isquemia Encefálica/cirugía , Accidente Cerebrovascular/cirugía , Trombectomía/instrumentación , Isquemia Encefálica/diagnóstico por imagen , Isquemia Encefálica/tratamiento farmacológico , Angiografía Cerebral , Terapia Combinada , Fibrinolíticos/uso terapéutico , Humanos , Persona de Mediana Edad , Estudios Retrospectivos , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/tratamiento farmacológico , Trombectomía/métodos , Trombectomía/mortalidad , Terapia Trombolítica , Activador de Tejido Plasminógeno/uso terapéutico , Resultado del TratamientoRESUMEN
We performed a prospective analysis on 14 11q- patients to determine the relationship between the degree of cognitive impairment and relative deletion size. Seventeen measures of cognitive function were assessed. All nine patients with a deletion of at least 12.1 Mb had severe global cognitive impairment, with full-scale IQ <50, whereas all five patients with smaller deletions, Asunto(s)
Mapeo Cromosómico
, Trastornos del Conocimiento/genética
, Proteínas de Homeodominio/genética
, Síndrome de Deleción Distal 11q de Jacobsen
, Trastornos Mentales/genética
, Proteínas del Tejido Nervioso/genética
, Neurogranina/genética
, Adolescente
, Adulto
, Animales
, Niño
, Deleción Cromosómica
, Cromosomas Humanos Par 11
, Femenino
, Humanos
, Síndrome de Deleción Distal 11q de Jacobsen/genética
, Síndrome de Deleción Distal 11q de Jacobsen/fisiopatología
, Masculino
, Ratones
, Análisis por Micromatrices
, Estudios Prospectivos
, Adulto Joven
RESUMEN
The proto-oncogene-encoded transcription factor c-Jun activates genes in response to a number of inducers that act through mitogen-activated protein kinase (MAPK) signal transduction pathways. The activation of c-Jun after phosphorylation by MAPK is accompanied by a reduction in c-Jun ubiquitination and consequent stabilization of the protein. These results illustrate the relevance of regulated protein degradation in the signal-dependent control of gene expression.
Asunto(s)
Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Proteínas Quinasas Activadas por Mitógenos , Proteínas Proto-Oncogénicas c-jun/metabolismo , Ubiquitinas/metabolismo , Células 3T3 , Animales , Proteínas de Ciclo Celular/metabolismo , Proteínas de Unión al GTP/metabolismo , Regulación de la Expresión Génica , Proteínas Quinasas JNK Activadas por Mitógenos , Ratones , Fosforilación , Transducción de Señal , Transfección , Proteína de Unión al GTP cdc42 de Saccharomyces cerevisiaeRESUMEN
The proto-oncogene products c-Fos and c-Jun heterodimerize through their leucine zippers to form the AP-1 transcription factor. The transcriptional activity of the heterodimer is regulated by signal-dependent phosphorylation and dephosphorylation events. The stability of c-Fos was found to also be controlled by intracellular signal transduction. In transient expression and in vitro degradation experiments, the stability of c-Fos was decreased when the protein was dimerized with phosphorylated c-Jun. c-Jun protein isolated from phorbol ester-induced cells did not target c-Fos for degradation, which suggests that c-Fos is transiently stabilized after stimulation of cell growth. v-Fos protein, the retroviral counterpart of c-Fos, was not susceptible to degradation targeted by c-Jun.
Asunto(s)
Proteínas Oncogénicas v-fos/metabolismo , Proteínas Proto-Oncogénicas c-fos/metabolismo , Proteínas Proto-Oncogénicas c-jun/metabolismo , Secuencia de Aminoácidos , Animales , Codón/genética , Células HeLa , Humanos , Sustancias Macromoleculares , Datos de Secuencia Molecular , Proteínas Oncogénicas v-fos/genética , Fosforilación , Biosíntesis de Proteínas , Proto-Oncogenes Mas , Proteínas Proto-Oncogénicas c-fos/genética , Proteínas Proto-Oncogénicas c-jun/genética , Conejos , Proteínas Recombinantes/metabolismo , Reticulocitos/metabolismo , Acetato de Tetradecanoilforbol/farmacología , Transcripción Genética , TransfecciónRESUMEN
Von Hippel-Lindau disease is an important hereditary tumor syndrome with a clear option for effective treatment if diagnosed in time. Interdisciplinary cooperation is the key to successful management. Major components of the disease are retinal capillary hemangioblastomas, hemangioblastomas of cerebellum, brain stem and spine, renal clear cell carcinomas, pheochromocytomas, multiple pancreatic cysts and islet cell carcinomas, tumors of the endolymphatic sac of the inner ear, and cystadenomas of the epididymis and broad ligament. A well structured screening program should be performed at yearly intervals.
Asunto(s)
Hemangioblastoma/terapia , Hemangioma/terapia , Oftalmología/historia , Patología/historia , Grupo de Atención al Paciente , Neoplasias de la Retina/terapia , Enfermedad de von Hippel-Lindau/historia , Enfermedad de von Hippel-Lindau/terapia , Adenocarcinoma de Células Claras/terapia , Neoplasias de las Glándulas Suprarrenales/terapia , Adulto , Diagnóstico Diferencial , Femenino , Alemania , Hemangioblastoma/diagnóstico , Hemangioma/diagnóstico , Historia del Siglo XIX , Historia del Siglo XX , Humanos , Relaciones Interprofesionales , Neoplasias Renales/terapia , Imagen por Resonancia Magnética , Masculino , Feocromocitoma/terapia , Tomografía de Emisión de Positrones , Derivación y Consulta , Neoplasias de la Retina/diagnóstico , Suecia , Enfermedad de von Hippel-Lindau/clasificación , Enfermedad de von Hippel-Lindau/diagnóstico , Enfermedad de von Hippel-Lindau/diagnóstico por imagen , Enfermedad de von Hippel-Lindau/genéticaRESUMEN
In vertebrates, 2 main genetic pathways have been shown to regulate ovarian development. Indeed, a loss of function mutations in Rspo1 and Foxl2 promote partial female-to-male sex reversal. In mice, it has been shown that the secreted protein RSPO1 is involved in ovarian differentiation and the transcription factor FOXL2 is required for follicular formation. Here, we analysed the potential interactions between these 2 genetic pathways and have shown that while Rspo1 expression seems to be independent of Foxl2 up-regulation, Foxl2 expression partly depends of Rspo1 signalisation. This suggests that different Foxl2-positive somatic cell lineages exist within the ovaries. In addition, a combination of both mutated genes in XX Foxl2(-/-)/Rspo1(-/-) gonads promotes sex reversal, detectable at earlier stages than in XX Rspo1(-/-) mutants. Ectopic development of the steroidogenic lineage is more pronounced in XX Foxl2(-/-)/Rspo1(-/-) gonads than in XX Rspo1(-/-) embryos, suggesting that Foxl2 is involved in preventing ectopic steroidogenesis in foetal ovaries.
Asunto(s)
Factores de Transcripción Forkhead/metabolismo , Trombospondinas/metabolismo , Animales , Trastornos del Desarrollo Sexual/genética , Femenino , Proteína Forkhead Box L2 , Factores de Transcripción Forkhead/genética , Genotipo , Hibridación in Situ , Masculino , Ratones , Ovario/embriología , Ovario/metabolismo , Fenotipo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Diferenciación Sexual/genética , Diferenciación Sexual/fisiología , Trombospondinas/genéticaRESUMEN
A surface magneto-optic Kerr effect (MOKE) setup fully integrated in an ultrahigh vacuum chamber is presented. The system has been designed to combine in situ MOKE and scanning tunneling microscopy. Magnetic fields up to 0.3 T can be applied at any angle in the transverse plane allowing the study of in-plane and out-of-plane magnetization. The setup performance is demonstrated for a continuous film of 0.9 monolayers (ML) Co/Rh(111) with in-plane easy axis and for a superlattice of nanometric double layer Co islands on Au(11,12,12) with out-of-plane easy axis. For Co/Au(11,12,12) we demonstrate that the magnetic anisotropy energies deduced from thermally induced magnetization reversal and from applying a torque onto the magnetization by turning the field are the same. For the presented setup we establish a coverage detection limit of 0.5 ML for transverse and 0.1 ML for polar MOKE. For island superlattices with the density of Co/Au(11,12,12), the latter limit corresponds to islands composed of about 50 atoms. The detection limit can be further reduced when optimizing the MOKE setup for either one of the two Kerr configurations.
RESUMEN
In a suicidal gunshot fired to the chest from a carbine, the barrel of which had been shortened to half its original length, an unexpectedly large degree of destruction of the anterior thoracic wall with extensive undermining of the subcutis was found. This phenomenon was investigated for reconstructive purposes by firing test shots from two different long guns (caliber 7.92 x 57 repeating rifle with full-jacketed pointed bullet and caliber 12/70 single-barreled shotgun with shotgun slug) into blocks of soap (38 x 25 x 25 cm). The contact shots were fired before and after shortening the barrels (repeating rifle from 60 to 30 cm and single-barreled shotgun from 72 to 36 cm). The volume of the cavities in the simulant was visualized three-dimensionally with the help of a multislice computed tomography (CT) scanner and calculated sectionally. With the repeating rifle and the single-barreled shotgun, the shots from the sawed-off barrels produced significantly larger cavity diameters in the first section of the bullet track. This effect is attributable to the fact that, with a shortened barrel, the gas pressure at the muzzle is higher, thus, leading to increased expansion in the initial part of the wound track in contact shots.
Asunto(s)
Armas de Fuego , Balística Forense , Heridas por Arma de Fuego , Humanos , Tomografía Computarizada por Rayos XAsunto(s)
Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/diagnóstico , Epilepsia del Lóbulo Temporal/etiología , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Neurocitoma/complicaciones , Neurocitoma/diagnóstico , Lóbulo Temporal/patología , Neoplasias Encefálicas/patología , Niño , Diagnóstico Diferencial , Dominancia Cerebral/fisiología , Epilepsia del Lóbulo Temporal/patología , Epilepsia del Lóbulo Temporal/cirugía , Humanos , Masculino , Neurocitoma/patología , Neurocitoma/cirugía , Lóbulo Temporal/cirugíaAsunto(s)
Infarto Cerebral/complicaciones , Infarto Cerebral/diagnóstico , Venas Cerebrales/patología , Hemorragia Subaracnoidea/diagnóstico , Hemorragia Subaracnoidea/etiología , Vasculitis/complicaciones , Adulto , Enfermedades del Sistema Nervioso Central/complicaciones , Resultado Fatal , Humanos , Imagen por Resonancia Magnética , Masculino , Sarcoidosis/complicaciones , Hemorragia Subaracnoidea/patología , Tomografía Computarizada por Rayos XRESUMEN
The detection of inflammatory and tumorous conditions of the colon is one of the main topics in current abdominal radiology. The barium enema was introduced first in 1923 by Fischer, and has represented the workhorse of intestinal diagnostics for decades. The widespread use of endoscopy and the ongoing technical improvements in CT and MRI, however, have led to an inevitable displacement of this technique. Nevertheless, radiographs and enema are frequently employed in the initial work-up of patients with suspected colonic disease. This article provides an overview of the most important entities of inflammatory and tumorous changes of the colon.
Asunto(s)
Bario , Colitis/diagnóstico , Neoplasias del Colon/diagnóstico , Imagen por Resonancia Magnética/métodos , Tomografía Computarizada por Rayos X/métodos , Humanos , Guías de Práctica Clínica como Asunto , Pautas de la Práctica en MedicinaRESUMEN
We have cloned and sequenced a large portion of the hunchback (hb) locus from Drosophila virilis. Comparison with the Drosophila melanogaster hb sequence shows multiple strong homologies in the upstream and downstream regions of the gene, including most of the known functional parts. The coding sequence is highly conserved within the presumptive DNA-binding finger regions, but more diverged outside of them. The regions of high divergence are correlated with regions which are rich in short direct repeats (regions of high 'cryptic simplicity'), suggesting a significant influence of slippage-like mechanisms in the evolutionary divergence of the two genes. Staining of early D.virilis embryos with an hb antibody reveals conserved and divergent features of the spatial expression pattern at blastoderm stage. It appears that the basic expression pattern, which serves as the gap gene function of hb, is conserved, while certain secondary expression patterns, which have separate functions for the segmentation process, are partly diverged. Thus, both slippage driven mutations in the coding region, which are likely to occur at higher rates than point mutations and the evolutionary divergence of secondary expression patterns may contribute to the evolution of regulatory genes.
Asunto(s)
Secuencia de Bases , Evolución Biológica , Drosophila/genética , Homología de Secuencia de Ácido Nucleico , Secuencia de Aminoácidos , Animales , Mapeo Cromosómico , ADN/genética , Drosophila melanogaster/genética , Regulación de la Expresión Génica , Inmunohistoquímica , Datos de Secuencia MolecularRESUMEN
Ubiquitin-dependent selective protein degradation serves to eliminate abnormal proteins and provides controlled short half-lives to certain cellular proteins, including proteins of regulatory function such as phytochrome, yeast MAT alpha 2 repressor, p53 and cyclin. Moreover, ubiquitin-dependent proteolysis is thought to play an essential role during development and in programmed cell death. We have cloned a gene from Drosophila melanogaster, UbcD1, coding for a protein with striking sequence similarity to the yeast ubiquitin-conjugating enzymes UBC4 and UBC5. These closely related yeast enzymes are known to be central components of a major proteolytic pathway of Saccharomyces cerevisiae. By doing a precise open reading frame replacement in the yeast genome we could show that the Drosophila UbcD1 enzyme can functionally substitute for yeast UBC4. UbcD1 driven by the UBC4 promoter rescues growth defects and temperature sensitivity of yeast ubc4 ubc5 double mutant cells. Moreover, expression of UbcD1 restores proteolysis proficiency in the ubc4 ubc5 double mutant, indicating that the Drosophila enzyme also mediates protein degradation. This structural and functional conservation suggests that the UbcD1-UBC4-UBC5 class of enzymes defines a major proteolytic pathway in probably all eukaryotes.
Asunto(s)
Drosophila melanogaster/genética , Ligasas/genética , Proteínas de Saccharomyces cerevisiae , Enzimas Ubiquitina-Conjugadoras , Ubiquitinas/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Drosophila melanogaster/enzimología , Prueba de Complementación Genética , Datos de Secuencia Molecular , Péptido Hidrolasas/metabolismo , Regiones Promotoras Genéticas/genética , Proteínas/metabolismo , Saccharomyces cerevisiae/genética , Homología de Secuencia de Ácido NucleicoRESUMEN
R7 photoreceptor fate in the Drosophila eye induced by the activation of the Sevenless receptor tyrosine kinase and the RAS/MAP kinase signal transduction pathway. We show that expression of a constitutively activated JUN isoform in ommatidial precursor cells is sufficient to induce R7 fate independent of upstream signals normally required for photoreceptor determination. We present evidence that JUN interacts with the ETS domain protein Pointed to promote R7 formation. This interaction is cooperative when both proteins are targeted to the same promoter and is antagonized by another ETS domain protein, YAN, a negative regulator of R7 development. Furthermore, phyllopod, a putative transcriptional target of RAS pathway activation during R7 induction, behaves as a suppressor of activated JUN. Taken together, these data suggest that JUN and Pointed act on common target genes to promote neuronal differentiation in the Drosophila eye, and that phyllopod might be such a common target.
Asunto(s)
Proteínas de Drosophila , Drosophila/fisiología , Células Fotorreceptoras de Invertebrados/citología , Proteínas Proto-Oncogénicas c-jun/fisiología , Proteínas Proto-Oncogénicas/fisiología , Proteínas Tirosina Quinasas Receptoras , Proteínas Represoras , Activación Transcripcional/fisiología , Animales , Secuencia de Bases , Diferenciación Celular , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/fisiología , Ojo/crecimiento & desarrollo , Proteínas del Ojo/genética , Proteínas del Ojo/fisiología , Genes Supresores/fisiología , Glicoproteínas de Membrana/genética , Modelos Genéticos , Datos de Secuencia Molecular , Proteínas del Tejido Nervioso , Proteínas Nucleares/genética , Fenotipo , Células Fotorreceptoras de Invertebrados/crecimiento & desarrollo , Fototropismo , Regiones Promotoras Genéticas/genética , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas c-jun/genética , Transducción de Señal/fisiología , Factores de Transcripción , Rayos Ultravioleta , Proteínas ras/fisiologíaRESUMEN
The DNA-binding activity of c-Jun is determined by the phosphorylation state of a cluster of threonine and serine residues located near its COOH-terminus. We have analyzed the events that lead to c-Jun activation via dephosphorylation of these sites in response to phorbol esters. Our results indicate that COOH-terminal dephosphorylation is an indirect consequence of a separate phosphorylation event targeted to the NH2-terminus of c-Jun. Thus, the activation of c-Jun DNA-binding potential, caused by COOH-terminal dephosphorylation, may not require the regulation of the kinase/phosphatase system that brings about this change, but rather an alteration in the accessibility of the COOH-terminal phosphoacceptor sites of c-Jun.
Asunto(s)
Proteínas Proto-Oncogénicas c-jun/metabolismo , Transducción de Señal , Secuencia de Aminoácidos , Sitios de Unión , ADN/genética , ADN/metabolismo , Células HeLa , Humanos , Datos de Secuencia Molecular , Mutación , Fosforilación , Proteínas Proto-Oncogénicas c-jun/genéticaRESUMEN
The role of the ubiquitin-dependent proteolysis system in c-Jun breakdown was investigated. Using in vitro experiments and a novel in vivo assay that utilizes molecularly-tagged ubiquitin and c-Jun proteins, it was shown that c-Jun, but not its transforming counterpart, retroviral v-Jun, can be efficiently multiubiquitinated. Consistently, v-Jun has a longer half-life than c-Jun. Mutagenesis experiments indicate that the reason for the escape of v-Jun from multiubiquitination and its resulting stabilization is the deletion of the delta domain, a stretch of 27 amino acids that is present in c-Jun but not in v-Jun. c-Jun sequences containing the delta domain, when transferred to the bacterial beta-galactosidase protein, function as a cis-acting ubiquitination and degradation signal. The correlation between transforming ability and the escape from ubiquitin-dependent degradation described here suggests a novel route to oncogenesis.
Asunto(s)
Ligasas/metabolismo , Proteínas Proto-Oncogénicas c-jun/metabolismo , Ubiquitinas/metabolismo , Secuencia de Aminoácidos , Animales , Células Cultivadas , Pollos , Análisis Mutacional de ADN , Endopeptidasas/metabolismo , Células HeLa , Humanos , Lisina/metabolismo , Datos de Secuencia Molecular , Proteína Oncogénica p65(gag-jun)/metabolismo , Conformación Proteica , Procesamiento Proteico-Postraduccional , Proteínas Proto-Oncogénicas c-jun/genética , Proteínas Recombinantes/metabolismo , Secuencias Reguladoras de Ácidos Nucleicos , Relación Estructura-Actividad , Ubiquitinas/genéticaRESUMEN
The ubiquitin/proteasome system is the main eukaryotic nonlysosomal protein degradation system. Substrate selectivity of this pathway is thought to be mediated in part by members of a large family of ubiquitin-conjugating (E2) enzymes, which catalyze the covalent attachment of ubiquitin to proteolytic substrates. E2 enzymes have a conserved approximately 150-residue so-called UBC domain, which harbors the cysteine residue required for enzyme-ubiquitin thioester formation. Some E2 enzymes possess additional carboxyl-terminal extensions that are involved in substrate specificity and intracellular localization of the enzyme. Here we describe a novel family of E2 enzymes from higher eukaryotes (Drosophila, mouse, and man) that have amino-terminal extensions but lack carboxyl-terminal extensions. We have identified four different variants of these enzymes that have virtually identical UBC domains (94% identity) but differ in their amino-terminal extensions. In yeast, these enzymes can partially complement mutants deficient in the UBC4 E2 enzyme. This indicates that members of this novel E2 family may operate in UBC4-related proteolytic pathways.
Asunto(s)
Ligasas/metabolismo , Ubiquitinas/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , ADN Complementario , Humanos , Ligasas/química , Ratones , Datos de Secuencia Molecular , Familia de Multigenes , Filogenia , Homología de Secuencia de AminoácidoRESUMEN
The transcriptional activities of c-Ets-1 and v-Ets and their functional interaction with the AP-1 factor c-Jun were investigated. Several recombinant Ets proteins were produced and purified either from bacteria or from insect cells. Plasmid DNAs that contained the polyoma virus enhancer Ets/AP-1 element were used as templates for in vitro transcription assays in the presence of HeLa nuclear extract and various combinations of the Jun and Ets proteins. Under these conditions full-length c-Ets-1 on its own does not markedly influence transcription but abolishes the strong transcriptional stimulation normally elicited by Jun. This repression depends on the Ets-binding site and on specific features of c-Ets-1 structure, as both v-Ets and a natural splicing variant c-Ets-1 (delta VII) fail to inhibit Jun activity. These findings suggest that c-Ets may act both as a transcriptional repressor or activator depending on promoter context and splicing pattern.