RESUMEN
Production of nitric oxide (NO) by macrophages is important for the killing of intracellular infectious agents. Interferon (IFN)-gamma and lipopolysaccharide stimulate NO production by transcriptionally up-regulating the inducible NO synthase (iNOS). Macrophages from mice with a targeted disruption of the IFN regulatory factor-1 (IRF-1) gene (IRF-1-/- mice) produced little or no NO and synthesized barely detectable iNOS messenger RNA in response to stimulation. Two adjacent IRF-1 response elements were identified in the iNOS promoter. Infection with Mycobacterium bovis (BCG) was more severe in IRF-1-/- mice than in wild-type mice. Thus, IRF-1 is essential for iNOS activation in murine macrophages.
Asunto(s)
Aminoácido Oxidorreductasas/biosíntesis , Proteínas de Unión al ADN/metabolismo , Macrófagos Peritoneales/enzimología , Fosfoproteínas/metabolismo , Factores de Transcripción/metabolismo , Aminoácido Oxidorreductasas/genética , Animales , Secuencia de Bases , Proteínas de Unión al ADN/genética , Inducción Enzimática , Factor 1 Regulador del Interferón , Interferones/farmacología , Lipopolisacáridos/farmacología , Activación de Macrófagos , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Datos de Secuencia Molecular , Mutación , Mycobacterium bovis , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa , Fosfoproteínas/genética , Regiones Promotoras Genéticas , ARN Mensajero/genética , ARN Mensajero/metabolismo , Secuencias Reguladoras de Ácidos Nucleicos , Factores de Transcripción/genética , Tuberculosis/inmunología , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
Internal and moving targets of scanning laser ophthalmoscopes are not capable of observing the fundus beyond a field of more than 80 degrees with high resolution. The authors enabled wide-angle fundus examination with high resolution through a modification of the target. Mirror image fixation targets(MIFT), which fixated the opposite side of the examined eye onto the mirror image of five lamps placed 1.5 m away from the patient, were used to observe the fundus during fluorescein angiography in five diabetic retinopathy patients. In three of them, the ranges of the fundus examinations were measured using conventional internal fixation targets. The mean ranges of the fundus examinations when using MIFT (77.2 +/- 2.5 degrees horizontally, 67.9 +/- 2.1 degrees vertically) were significantly wider than when using internal fixation targets (65.5 +/- 2.6 degrees horizontally, 44.4 +/- 2.8 degrees vertically). MIFT provided a wide angle fundus view with high resolution equal to that of 40 degrees angle images using a scanning laser ophthalmoscope.
Asunto(s)
Retinopatía Diabética/diagnóstico , Angiografía con Fluoresceína/métodos , Aumento de la Imagen , Rayos Láser , Retina/patología , Pruebas del Campo Visual/métodos , Femenino , Fondo de Ojo , Humanos , Masculino , Persona de Mediana Edad , Oftalmoscopía/métodos , Reproducibilidad de los ResultadosRESUMEN
Detailed genetic analysis of Endomyces fibuliger, an amylolytic yeast which is homothallic and exists predominantly in the diploid state, has not been performed. From a naturally occurring strain, E. fibuliger 8014 met, a morphological mutant, 193 met, was obtained by u.v. mutagenesis. To obtain a haploid strain suitable for genetic analysis, an intergeneric hybrid between E. fibuliger 193 met and a strain of a closely related dimorphic heterothallic lipolytic yeast, Yarrowia lipolytica, A his1, was produced by mass mating. The intergeneric hybrid was highly unstable in vegetative culture on yeast extract/phosphate/soluble starch/agar media and produced numerous mitotic sectors. Most of the sectors were mitotically unstable. However, one mitotically stable sector, N14i60 met, was obtained which also differed from the strain 193 as gauged by the appearance of DNA bands on pulsed-field gel electrophoresis. The putative haploid strain, N14i60 met, had six bands whilst the mutant 193 met had seven. Ultra-violet treatment of cells of N14i60 met produced 19 auxotrophic mutants. Protoplast fusion between pairs of different mutants showed complementation and the fusants were unstable mitotically and gave unstable aneuploid and stable haploid sectors of parental and non-parental combinations of markers. It is postulated that complementary diploid fusants, which were obtained by protoplast fusion, produced sectors by mitotic non-disjunction. Such a mechanism provides a means to establish a genetic analysis system for E. fibuliger via the parasexual cycle.