RESUMEN
A preterm female infant presented with intractable hypoglycaemia within 10 minutes of delivery. Normoglycaemia could be maintained only by the intravenous infusion of glucose at a rate of 20-22 mg/kg/min. Persistent hyperinsulinaemic hypoglycaemia of infancy was diagnosed from an inappropriately raised plasma insulin concentration (33 mU/l) at the time of hypoglycaemia (blood glucose < 0.5 mmol/l). Medical treatment with glucagon, somatostatin, and diazoxide led to only a modest reduction in the intravenous glucose requirement; a 95% pancreatectomy was performed and histological 'nesidioblastosis' confirmed. In vitro electrophysiological studies using patch clamp techniques on isolated pancreatic beta cells characterised the ionic basis for insulin secretion in nesidioblastosis. The beta cells were depolarised in low ambient glucose concentrations with persistently firing action potentials; these were blocked reversibly by the calcium channel blocking agent verapamil. Persistent postoperative hyperinsulinaemic hypoglycaemia was treated with oral nifedipine. This increased median blood glucose concentrations from 3.5 to 4.8 mmol/l and increased in duration the child's tolerance to fasting from 3 to 10.5 hours. These data allude to an abnormality in the ionic control of insulin release in nesidioblastosis and offer a new logical approach to treatment which requires further evaluation.
Asunto(s)
Bloqueadores de los Canales de Calcio/uso terapéutico , Canales de Calcio/fisiología , Enfermedades del Prematuro/fisiopatología , Islotes Pancreáticos/fisiopatología , Nifedipino/uso terapéutico , Enfermedades Pancreáticas/fisiopatología , Glucemia/metabolismo , Electrofisiología , Femenino , Humanos , Recién Nacido , Recien Nacido Prematuro , Enfermedades del Prematuro/sangre , Enfermedades del Prematuro/tratamiento farmacológico , Enfermedades Pancreáticas/sangre , Enfermedades Pancreáticas/tratamiento farmacológico , Técnicas de Placa-ClampRESUMEN
Children with allergic colitis have low levels of zinc and selenium which is partly a reflection of their low albumin levels and/or increased utilization of zinc and selenium as antioxidants as a result of the inflammatory process.
Asunto(s)
Colitis/sangre , Cobre/deficiencia , Hipersensibilidad a la Leche/sangre , Selenio/deficiencia , Albúmina Sérica/deficiencia , Zinc/deficiencia , Estudios de Casos y Controles , Preescolar , Colitis/inmunología , Cobre/sangre , Humanos , Lactante , Hipersensibilidad a la Leche/inmunología , Estado Nutricional , Selenio/sangre , Albúmina Sérica/análisis , Zinc/sangreRESUMEN
1. Recent initiatives which advocate an increase in dietary polyunsaturated fat intake have led to the study of the effects of this upon gastrointestinal function. 2. Weanling rats were for 21 weeks fed diets containing 10% fat that were either high or low in polyunsaturated fats. Jejunal function was studied in vitro in an Ussing chamber. 3. Basal intestinal short-circuit was similar in both groups. 4. A decreased EC50 for the non-neural electrogenic secretory responses to acetylcholine, bethanecol and isobutylmethylxanthine was apparent in the jejuna of rats fed a diet high in polyunsaturated fatty acids. 5. Submaximal electrogenic galactose absorption was increased in the rats fed a diet high in polyunsaturated fatty acids. 6. Changing the composition of dietary lipid resulted in a change in the fatty composition of the apical enterocyte membrane. 7. Diets high in polyunsaturated fatty acids may be both prosecretory and proabsorptive in the small intestine.