CEREBRAL METABOLIC STUDIES BY 1H-13C NMR IN VIVO

该项目将使用新开发的化学特异性，非侵入性 磁共振波谱方法研究脑代谢， 人类 1H方法将用于研究脑衰退的速度 苯丙氨酸在年轻成人苯丙酮尿症谁去低苯丙氨酸 在选择之前不遵循这样的饮食后， 寻找中风患者脂质降解的证据， 痴呆 将使用1H和13 C组合方法监测 氨基中13 C的进入和最终稳态13 C部分富集 当给予13 C标记葡萄糖时， 静脉注射 氨基酸标记的变异范围及最佳标记条件 将在以下正常受试者中确定1- 13 C-葡萄糖输注时间表： 在安静的清醒状态下， 刺激和痴呆和复杂部分性癫痫患者。 脑乳酸升高中风将进行研究，以评估其稳定 说明13 C富集分数作为缺血半影测量。 这一结果有望为正常脑组织的研究提供新的信息 代谢和病理生理过程如何在工作中， 痴呆、中风和癫痫会影响葡萄糖进入脑内的速率， 脑、升高的乳酸池的代谢活性和氨基代谢率 酸周转

This project will use newly developed chemically specific, non-invasive magnetic resonance spectroscopic methods to study cerebral metabolism in humans. 1H methods will be used to study the rate of decline of brain phenylalanine in young adult phenylketonurics who go on a low-phenylalanine diet after having chosen previously not to follow such a diet, and to search for evidence of lipid degradation in patients with stroke and dementia. Combined 1H and 13C methods will be used to monitor rates of entry of 13C and eventual steady state 13C fractional enrichment in amino acid and elevated lactate pools when 13C-labeled glucose is given intravenously. The range of variation of amino acid labeling and optimum 1-13C-glucose infusion schedules will be determined in normal subjects of varying age and weight during quiet wakefulness, and then during sensory stimulation and in patients with dementia and complex partial epilepsy. Cerebral lactate elevated by stroke will be studied to evaluate it steady state 13C fractional enrichment as a measure of an ischemic penumbra. The results are expected to provide new information about normal cerebral metabolism and about how the pathophysiological processes at work in dementia, stroke, and epilepsy affect the rate of glucose entry into the brain, the metabolic activity of elevated lactate pools, and rates of amino acid turnover.