Amino acid neonatal

Brain Coordination of the nervous system Glycolysis, amino acid metabolism Glucose, amino acid, ketone bodies (in starvation) Polyunsaturated fatty acids in neonate Lactate ... 

Fig. 1. Amino acid sequence homology between the neonatal fast-twitch and slow-twitch skeletal muscle forms of the Ca -ATPase. The sequence of the slow Ca -ATPase is shown above the neonatal fast-twitch form, with nonhomologous amino acids indicated by asterisks. The sequence of the slow ATPase is shifted to the right by one residue at residue 505 to allow realignment after the difference in sequence length. Ml-MlO, membrane spanning regions S1-S5, stalk sectors Tl, T2, major tryptic cleavage sites P,...

The cDNA clone for the neonatal rabbit fast-twitch skeletal muscle Ca -ATPase encodes for 1001 amino acids giving a product with an estimated molecular weight of 110 331 Da [8], The clone for the Ca -ATPase of slow-twitch skeletal muscle sarcoplasmic reticulum (S-Ca -ATPase) encoded for 997 amino acids with a relative molecular mass (Mr) of 109 529 kDa [42],... 

Mantagos, S., Moustogianni, A., Varvarigou, A., Frimas, C. (1989). Effect of light on diurnal variation of blood amino acids in neonates. Biol. Neonate 55, 97-103. 

An aminoaciduria usually results from the congenital absence of an enzyme needed for metabolism of an amino acid. Aminoacidopathies typically involve an inherited deficiency of an enzyme that is important for the metabolism of a particular amino acid (Table 40-1). The concentration of that amino acid and its metabolites consequently rise sharply in blood, urine and body tissues, including the brain. When the enzymatic deficiency is nearly complete, the onset of disease tends to occur in infancy, even in the neonatal period. Partial enzyme deficiencies may not become apparent until later in life [1,2]. 

Age does not have a major influence on amino acid levels, with exception of the neonatal period. Premature babies may have underdeveloped hepatic and renal function, leading to increased tyrosine and methionine in their plasma as well as enhanced urinary losses of cystine, lysine, glycine, proline, hydroxyproline, and cystathionine. Taurine levels are generally increased in the first days of life. 

Nutrition may have a considerable effect. A high intake of milk protein in neonates will result in an increase in most plasma amino acids, especially methionine and tyrosine. Canned infant formulae may contain homocitrulline, which may appear in the patient s urine. White meat (chicken ) will contain carnosine, anserine, and... 

Reference values for amino acids in the urine show a rather sharp decrease from the neonatal period to adulthood (Table 2.1.6). This is mainly due to the maturation of the renal tubular reabsorption system, but is also the result of increasing muscle mass with age, giving rise to increasing creatinine production. 

Peptidyl transferase is also involved in termination. When the final, or terminal, amino acid has been added to the peptidic sequence, that enzyme releases the neonate peptide from the 60s ribosome. Mg2+, GTP, and other release factors (RF s) are necessary for complete release. Also, at this stage, the new peptide has both at least one terminal and carboxyl function, which may interact with foreign molecules. 

Phase II This phase consists of conjugation reactions. If the metabolite from Phase I metabolism is sufficiently polar, it can be excreted by the kidneys. However, many metabolites are too lipophilic to be retained in the kidney tubules. A subsequent conjugation reaction with an endogenous substrate, such as glucuronic acid, sulfuric acid, acetic acid or an amino acid results in polar, usually more water-soluble compounds that are most often therapeutically inactive. Glucuronidation is the most common and the most important conjugation reaction. Neonates are deficient in... 

Dehydrogenase Deficiency, Biotinidase Deficiency, and Adrenoleukodystrophy. Catabolism of essential amino acid skeletons is discussed in the chapters Phenylketonuria and HMG-CoA Lyase Deficiency. The chapters Inborn Errors of Urea Synthesis and Neonatal Hyperbilirubinemia discuss the detoxification and excretion of amino acid nitrogen and of heme. The chapter Gaucher Disease provides an illustration of the range of catabolic problems that result in lysosomal storage diseases. Several additional chapters deal with key aspects of intracellular transport of enzymes and metabolic intermediates the targeting of enzymes to lysosomes (I-Cell Disease), receptor-mediated endocytosis (Low-Density Lipoprotein Receptors and Familial Hypercholesterolemia) and the role of ABC transporters in export of cholesterol from the cell (Tangier disease). 

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