RESUMEN
Primary hyperaldosteronism is a potential cause of hypertension. Unilateral adrenal adenoma and bilateral adrenal cortical hyperplasia are the most common causes of primary hyperaldosteronism. Adrenal venous sampling is employed as the gold standard test to differentiate between these two different causes when the results of other studies in the work-up protocol are non-diagnostic or ambiguous. Adrenal venous sampling can be a challenging procedure, especially in the presence of anomalous venous drainage patterns. Knowledge of normal adrenal venous anatomy, as well as possible variants, is therefore important to ensure a successful procedure. The authors describe an unusual variant of left adrenal venous drainage directly into the IVC.
Asunto(s)
Glándulas Suprarrenales/irrigación sanguínea , Venas/anomalías , Vena Cava Inferior/anomalías , Enfermedades de las Glándulas Suprarrenales/complicaciones , Enfermedades de las Glándulas Suprarrenales/diagnóstico , Recolección de Muestras de Sangre , Diagnóstico Diferencial , Humanos , Hiperaldosteronismo/etiología , Masculino , Persona de Mediana EdadRESUMEN
RATIONALE AND OBJECTIVES: The purpose of this study was to test the effectiveness of resident-prepared, independent learning cases in teaching residents chest radiology. MATERIALS AND METHODS: Three 2nd-year residents (one each from the University of Wisconsin, the Oregon Health Sciences University, and the University of Michigan) prepared four chest radiology teaching cases each (total, 12 cases). Radiology residents from each institution were randomly divided into control (n = 30) and experimental (n = 35) groups. Residents from both groups took a pretest of 36 multiple-choice questions covering the material from the 12 teaching cases. Residents in the experimental group reviewed these cases independently, and both groups took the same test (posttest) immediately after the teaching cases had been reviewed and again 3 months later (final test). RESULTS: Test scores were similar across institutions (P > .05) but differed across time and treatment groups (experimental vs control) (P < .0001). Mean differences in test scores between the experimental and control groups at pretest, posttest, and final test were -0.4, +9.0, +4.0, respectively, demonstrating increased performance at posttesting that was still present (though somewhat attenuated) 3 months later at final testing. CONCLUSION: Independent study of resident-prepared chest radiology teaching cases increases the resident's knowledge for as long as 3 months after instruction.
Asunto(s)
Internado y Residencia , Aprendizaje , Radiografía Torácica , Radiología/educación , Enseñanza/métodos , Análisis de Varianza , Competencia Clínica , Diagnóstico Diferencial , Evaluación Educacional , Estudios de Seguimiento , Humanos , Tomografía Computarizada por Rayos XRESUMEN
We have studied the structure and expression of histone H2B mRNA and genes in the parasitic protozoan Leishmania enrietti. A genomic clone containing three tandemly repeated genes has been sequenced and shown to encode three identical histone proteins and two types of closely related mRNA sequence. We have also sequenced three independent cDNA clones and demonstrated that the Leishmania H2B mRNAs are polyadenylated, similar to the basal histone mRNAs of higher eucaryotes and the histone mRNAs of yeast. In addition, the Leishmania mRNAs contain inverted repeats near the poly(A) tail which could form stem-loops similar in secondary structure, but not in sequence, to the 3' stem-loops of nonpolyadenylated replication-dependent histones of higher eucaryotes. Unlike the replication-dependent histones, the Leishmania histone H2B mRNAs do not decrease in abundance following treatment with inhibitors of DNA synthesis. The histone mRNAs are differentially expressed during the parasite life cycle and accumulate to a higher level in the extracellular promastigotes (the form which in nature lives within the gut of the insect vector) than in the intracellular amastigotes (the form that lives within the mammalian host macrophages).
Asunto(s)
Genes , Histonas/genética , Leishmania mexicana/genética , ARN Mensajero/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Northern Blotting , Southern Blotting , Clonación Molecular , ADN , ADN Protozoario/genética , Expresión Génica , Enlace de Hidrógeno , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , ARN Protozoario/genética , Mapeo RestrictivoRESUMEN
A membrane transport protein of the glucose transporter superfamily from Leishmania enriettii is encoded by a family of tandemly repeated genes. The first gene in this tandem repeat codes for a structural isoform that contains a unique amino-terminal hydrophilic domain, probably located in the cytoplasm; the remainder of the protein is identical to the polypeptide encoded by the internal genes in the tandem repeat. The unique isoform is represented by a distinct stable RNA.