RESUMEN
OBJECTIVE: To assess the effects of consuming foods containing oat beta-glucan on blood pressure, carbohydrate homeostasis and biomarkers of oxidative stress. DESIGN: A randomized, double-blind, controlled clinical trial. SETTING: The trial was conducted at two clinics. SUBJECTS AND INTERVENTIONS: Ninety-seven men and women with resting systolic blood pressure 130-179 mm Hg and/or diastolic blood pressure 85-109 mm Hg were randomly assigned to consume foods containing oat beta-glucan or control foods for 12 weeks. Resting blood pressures, insulin and glucose values before and after standard breakfast meals, and four biomarkers of oxidative stress were measured before and at the end of the treatment period. RESULTS: Changes from baseline to week 12 in mean peak insulin and incremental area under the insulin curve differed significantly between groups (P=0.037 and 0.034, respectively), with the beta-glucan group showing declines and the control group remaining essentially unchanged. Blood pressure responses were not significantly different between groups overall. However, in subjects with body mass index above the median (31.5 kg/m(2)), both systolic (8.3 mm Hg, P=0.008) and diastolic (3.9 mm Hg, P=0.018) blood pressures were lowered in the beta-glucan group compared to controls. No significant differences in biomarkers of oxidative stress were observed between treatments. CONCLUSIONS: The results of the present trial suggest beneficial effects of foods containing beta-glucan from oats on carbohydrate metabolism, and on blood pressure in obese subjects.
Asunto(s)
Presión Sanguínea/efectos de los fármacos , Metabolismo de los Hidratos de Carbono/efectos de los fármacos , Hipertensión/metabolismo , Obesidad/metabolismo , Estrés Oxidativo/efectos de los fármacos , beta-Glucanos/farmacología , Área Bajo la Curva , Avena/química , Biomarcadores/sangre , Glucemia , Fibras de la Dieta/metabolismo , Fibras de la Dieta/farmacología , Método Doble Ciego , Femenino , Humanos , Hipertensión/dietoterapia , Insulina/sangre , Masculino , Persona de Mediana Edad , Obesidad/dietoterapia , beta-Glucanos/metabolismoRESUMEN
BACKGROUND: . The morphological and functional evolution of appendages has played a critical role in animal evolution, but the developmental genetic mechanisms underlying appendage diversity are not understood. Given that homologous appendage development is controlled by the same Hox gene in different organisms, and that Hox genes are transcription factors, diversity may evolve from changes in the regulation of Hox target genes. Two impediments to understanding the role of Hox genes in morphological evolution have been the limited number of organisms in which Hox gene function can be studied and the paucity of known Hox-regulated target genes. We have therefore analyzed a butterfly homeotic mutant 'Hindsight', in which portions of the ventral hindwing pattern are transformed to ventral forewing identity, and we have compared the regulation of target genes by the Ultrabithorax (Ubx) gene product in Lepidopteran and Dipteran hindwings. RESULTS: . We show that Ubx gene expression is lost from patches of cells in developing Hindsight hindwings, correlating with changes in wing pigmentation, color pattern elements, and scale morphology. We use this mutant to study how regulation of target genes by Ubx protein differs between species. We find that several Ubx-regulated genes in the Drosophila haltere are not repressed by Ubx in butterfly hindwings, but that Distal-less (Dll) expression is regulated by Ubx in a unique manner in butterflies. CONCLUSIONS: . The morphological diversification of insect hindwings has involved the acquisition of different sets of target genes by Ubx in different lineages. Changes in Hox-regulated target gene sets are, in general, likely to underlie the morphological divergence of homologous structures between animals.
Asunto(s)
Mariposas Diurnas/crecimiento & desarrollo , Proteínas de Unión al ADN/fisiología , Proteínas de Drosophila , Regulación del Desarrollo de la Expresión Génica , Genes Homeobox , Proteínas de Homeodominio/fisiología , Proteínas de Insectos/fisiología , Factores de Transcripción , Alas de Animales/crecimiento & desarrollo , Animales , Mariposas Diurnas/genética , Proteínas de Unión al ADN/genética , Dípteros/genética , Dípteros/crecimiento & desarrollo , Evolución Molecular , Proteínas de Homeodominio/genética , Hibridación in Situ , Proteínas de Insectos/genética , Datos de Secuencia Molecular , Morfogénesis/genética , Homología de Secuencia de Ácido Nucleico , Especificidad de la Especie , Alas de Animales/ultraestructuraRESUMEN
BACKGROUND: Lepidopteran wing scales are the individual units of wing color patterns and were a key innovation during Lepidopteran evolution. On the basis of developmental and morphological evidence, it has been proposed that the sensory bristles of the insect peripheral nervous system and the wing scales of Lepidoptera are homologous structures. In order to determine if the developmental pathways leading to Drosophila sensory bristle and butterfly scale formation use similar genetic circuitry, we cloned, from the butterfly Precis coenia, a homolog of the Drosophila achaete-scute (AS-C) genes--which encode transcription factors that promote neural precursor formation--and examined its expression pattern during development. RESULTS: During embryonic and larval development, the expression pattern of the AS-C homolog, ASH1, forecasted neural precursor formation. ASH1 was expressed both in embryonic proneural clusters--within which an individual cell retained ASH1 expression, enlarged, segregated, and became a neural precursor--and in larval wing discs in putative sensory mother cells. ASH1 was also expressed in pupal wings, however, in evenly spaced rows of enlarged cells that had segregated from the underlying epidermis but, rather than give rise to neural structures, each cell contributed to an individual scale. CONCLUSIONS: ASH1 appears to perform multiple functions throughout butterfly development, apparently promoting the initial events of selection and formation of both neural and scale precursor cells. The similarity in the cellular and molecular processes of scale and neural precursor formation suggests that the spatial regulation of an AS-C gene was modified during Lepidopteran evolution to promote scale cell formation.