Asunto(s)
Angiografía de Substracción Digital/métodos , Angiografía Cerebral/métodos , Medios de Contraste , Gadolinio DTPA , Aneurisma Intracraneal/diagnóstico por imagen , Enfermedades Renales Poliquísticas/complicaciones , Insuficiencia Renal/complicaciones , Medios de Contraste/administración & dosificación , Creatinina/sangre , Femenino , Gadolinio DTPA/administración & dosificación , Humanos , Inyecciones Intravenosas , Persona de Mediana Edad , Intensificación de Imagen Radiográfica , Insuficiencia Renal/sangreRESUMEN
We compared 12-lead electrocardiographic changes during exercise in 41 patients with left bundle branch block; 7 were nonischemic and 34 had coronary artery obstruction > or =70% as detected by angiogram. ST depression of > or =0.5 mm from baseline when measured at the J point in leads II and AVF (p=0.004) and an increase of R-wave amplitude in lead II (p=0.05) significantly identified ischemia.
Asunto(s)
Bloqueo de Rama/diagnóstico , Electrocardiografía , Prueba de Esfuerzo/efectos adversos , Isquemia Miocárdica/diagnóstico , Bloqueo de Rama/etiología , Humanos , Isquemia Miocárdica/etiología , Pronóstico , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y EspecificidadRESUMEN
EGFR signaling has been shown in recent years to be involved in the determination, differentiation and maintenance of neural and epidermal cells of the ventral midline (mesectoderm and ventromedial ectoderm). Localized activation of the TGFalpha homolog Spitz (Spi) in the mesectoderm is achieved by the products of the genes rhomboid and Star. Spi binds to its receptor, the Drosophila epidermal growth factor receptor homolog (Egfr), and triggers the Ras pathway which is needed for the survival and differentiation of ventral midline cells. The results reported here indicate that EGFR signaling is also required in a narrow medial domain of the head ectoderm (called 'head midline' in the following) that includes the anlagen of the medial brain, the visual system (optic lobe, larval eye) and the stomatogastric nervous system (SNS). We document that genes involved in EGFR signaling are expressed in the head midline. Loss of EGFR signaling results in an almost total absence of optic lobe and larval eye, as well as severe reduction of SNS and medial brain. The cellular mechanism by which this phenotype arises is a failure of neurectodermal cells to differentiate combined with apoptotic cell death. Overactivity of EGFR signaling, as achieved by heat-shock-driven activation of a wild-type rhomboid (rho) construct, or by loss of function of argos (aos) or yan, results in an hyperplasia and deformity of the head midline structures. We show that, beside their requirement for EGFR signaling, head and ventral midline structures share several morphogenetic and molecular properties.
Asunto(s)
Drosophila/embriología , Receptores ErbB/fisiología , Sistema Nervioso/embriología , Animales , Tipificación del Cuerpo , Diferenciación Celular , Drosophila/genética , Drosophila/fisiología , Ectodermo/citología , Células Epiteliales/citología , Receptores ErbB/genética , Regulación del Desarrollo de la Expresión Génica , Genes de Insecto , Cabeza , Mutación , Sistema Nervioso/citología , Neuronas/citología , Transducción de Señal , Células Madre/citologíaRESUMEN
Radiation leukemia virus (RadLV)-induced preleukemic (PL) latency is characterized by the appearance of virus-infected PL cells in the thymus. The survival of these PL cells is dependent upon autostimulation with interleukin 4 (IL-4). We have intervened prophylactically in RadLV-induced preleukemia by using cyclosporin-A (CSA), which inhibits IL-4 production, and an immunotoxin (ITx) that kills PL cells. CSA efficiently inhibited IL-4 secretion from RadLV-induced PL and leukemic cells, and its administration to PL mice caused a significant delay in their death. An ITx consisting of anti-RadLV glycoprotein-70 (gp70) antibody coupled to ricin A chain efficiently inhibited protein synthesis in virus-infected cells in vitro and, when injected into PL mice, also delayed their death. Combined treatment with CSA and ITx prevented 75% of the treated PL mice from developing lymphoma. These results show that the development of malignancy from a premalignant state can be averted by a combination of therapeutic modalities that decrease the size and growth rate of the premalignant cell population.