RESUMO
The Na+/myo-inositol cotransporter (SLC5A3) gene, located on the long arm of human chromosome 21, may play a key role in osmoregulation including the regulation of levels of the "idiogenic osmole," myo-inositol, in brain cells. To determine whether the levels of myo-inositol are increased in the basal ganglia of children with Down syndrome, we performed in vivo brain hydrogen 1-nuclear magnetic resonance or 1H-magnetic resonance spectroscopy and measured plasma osmolality in a cohort of children with trisomy 21. Myo-inositol is elevated in the corpus striatum of infants and children with Down syndrome, even in the absence of hypertonic stress.
Assuntos
Gânglios da Base/metabolismo , Síndrome de Down/sangue , Inositol/sangue , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Espectroscopia de Ressonância Magnética , Masculino , Concentração OsmolarRESUMO
O ciclo intracelular do fosfoinositol (PI) e uma via de segundos mensageiros que pode estar desregulada em pacientes com disturbio bipolar. Essa hipotese tem sido investigada em alguns laboratorios com o uso de modelos plaquetarios, celulas sanguineas ou tecidos cerebrais de autopsia. Recentemente novos dados tem sido publicados sugerindo um aumento dos niveis ou da atividade de alguns intermediarios desta via em pacientes com disturbio bipolar; relatos de aumento da atividade da proteina quinase C (PKC) em pacientes nao medicados na fase maniaca e aumento da liberacao de Ca++ intracelular, em conjunto com achados de aumento do conteudo de fosfoinositois na membrana, sao condizentes com a hipotese de uma hiperfuncao do ciclo intracelular do PI nesse disturbio...
Assuntos
Transtorno Bipolar/fisiopatologia , Ativação Plaquetária , Fosfatidilinositóis/metabolismo , Transtorno Bipolar/enzimologia , Transtorno Bipolar/metabolismo , Transtorno Bipolar/patologia , Ciclo Celular , Inositol/análise , Inositol/sangue , Análise Espectral/métodos , Imageamento por Ressonância Magnética , Tomografia Computadorizada de EmissãoRESUMO
Inositol or placebo was given to 48 small preterm infants with respiratory distress syndrome (mean birth weight 1365 g, gestational age 30.1 weeks) between 48 hours and 10 days of age. The dose of inositol, 40 mg/kg every 6 hours, was at least as high as amounts received in full preterm human milk feedings. Serum inositol concentration increased between days 2 and 3 from a mean of 566 mumol/L to 823 mumol/L in the infants given supplement and fell from 451 mumol/L to 292 mumol/L in the controls. On day 16, serum inositol values remained higher in the infants given supplement than in those given placebo (mean 334 mumol/L vs 146 mumol/L, P = 0.014). The infants who developed bronchopulmonary dysplasia had significantly higher renal inositol clearance, lower inositol intake, and lower serum inositol concentrations. Inositol supplementation increased the saturated phosphatidylcholine/sphingomyelin ratio in tracheal aspirates. According to these results, supplementation with inositol in preterm infants leads to a rise in serum inositol concentration and improvement in the surfactant phospholipids. Inositol deserves further study as a dietary supplement for immature preterm infants who do not receive full human milk feeds.