Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The low cerebral energy requirements of most mammals at birth reflect an immaturity of the central nervous system, and it has been suggested that energy demands in fetuses are even less well developed than in newborns. Furthermore, fetal cerebral energy requirements are presumed to be met predominantly or exclusively by anaerobic glycolysis. To clarify these issues, we investigated cerebral oxidative metabolism in 9-, 14-, 16-, and 19-day-old chick embryos and in newly hatched peeps. Animals were decapitated and quick-frozen in liquid Freon 0--5 min post-mortem. Forebrain extracts were prepared and assayed for ATP, phosphocreatine, glucose, and lactate. Alterations in these metabolites post-decapitation were used to calculate cerebral metabolic rates (delta similar to P) and rates of maximal anaerobic glycolysis (delta lactate). Rates of lactate accumulation during cerebral ischemia increased progressively from embryonic day 9 through hatching. Cerebral metabolic rates were not different in 9-, 14-, and 15-day-old embryos, but increased steadily thereafter. The extent to which total cerebral energy utilization could be derived from anaerobic glycolysis (delta lactate/delta similar to P) increased from a low at day 9 (0.29) to a maximum at day 16 (0.78). The data suggest that, despite the low cerebral metabolic activity of the chick embryo, at no time during development is anaerobic glycolysis capable of entirely supporting the energy needs of the developing brain.
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PMID:Ontogeny of cerebral oxidative metabolism in the chick embryo. 706 56

To evaluate brain dysfunction in autism, proton magnetic resonance spectroscopy (1H-MRS) was performed for 29 autistic patients (5-15 y.o.) and 19 normal children (6-14 y.o.). We obtained magnetic resonance (MR) spectra of the left and right amygdaloid-hippocampal regions and the left cerebellar hemisphere with a STEAM sequence (TR = 5000 ms, TE = 18 ms). In addition to the evaluation of signal intensity ratios, the absolute concentration of three major metabolites (N-acetylaspartate [NAA], creatine/phosphocreatine [Cr] and choline-containing substances [Cho]) was quantified by an internal reference method using unsuppressed tissue water. Although no abnormal MR images were found in the three regions examined, the signal intensity and the concentration of NAA in the left amygdaloid-hippocampal region and the left cerebellar hemisphere were reduced significantly in autistic patients compared to normal children. We speculated that this decrease in NAA reflected neuronal loss, immaturity or hypofunction in these regions. The results of our study were in agreement with those of previous studies on autism, one by neuropathological methods and the other using a single photon emission computed tomography with 99mTc HMPAO. Disorders of the amygdaloid-hippocampal region and cerebellum are considered to play an important role in the characteristic cognitive and emotional dysfunction in autism. 1H-MRS is a valuable tool to clarify the pathophysiology of autism.
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PMID:[Proton magnetic resonance spectroscopy of the autistic brain]. 1149 76