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At least 1,567 records · Page 87Linked to original sources
PubMed1995

Use of human somatotrophin in the treatment of a patient with methylmalonic aciduria.

Growth hormone (GH) insufficiency was demonstrated in a patient with methylmalonic aciduria. GH administration at 14-21 U/m2 per week accelerated linear growth, stimulated lipolysis, and produced clinical improvement and reduced urinary methylmalonate excretion. The clinical and metabolic benefits were lost as the dose of GH was increased to 28 U/m2 per week. CONCLUSION. The use of GH in other patients with methylmalonic aciduria (and other disorders of intermediary metabolism demonstrating similar clinical and metabolic features) warrants further study.

Amino Acid Metabolism, Inborn Errors↗
PubMed1992

Rat bone marrow erythroid cell fractionation by counter current distribution in non-charge-sensitive two-phase systems.

Counter-current distribution in non charge-sensitive aqueous poly(ethylene glycol)-dextran two phase systems allows the fractionation of rat bone marrow cells into two broad cell subpopulations with different distribution coefficients in a relatively short time. Morphological identification and enzymatic studies suggest that erythroid cells are mainly present in the subpopulation with the higher distribution coefficient. The distribution coefficient and, therefore, surface hydrophobicity of these cells, apparently increase in parallel with an increase in their degree of differentiation and maturation.

Animals↗
PubMed1996

Dietary folate affects the response of rats to nickel deprivation.

Because vitamin B12 and Ni are known to interact and because of the similar metabolic roles of vitamin B12 and folate, an experiment was performed to determine the effect of dietary folate on Ni deprivation in rats. A 2 x 2 factorially arranged experiment used groups of nine weanling Sprague-Dawley rats. Dietary variables were Ni, as NiCl(2) 6H(2)0, 0 or 1 mu g/g; and folic acid, 0 or 2 mg/kg. The basal diet, based on skim milk, contained less than 20 ng Ni/g. After 54 d, an interaction between dietary Ni and folate affected several variables including erythrocyte folate, plasma amino acids, and femur trace elements. For example, folate deprivation decreased erythrocyte folate; folate supplementation to the Ni-supplemented rats caused a larger increase in erythrocyte folate concentration than did folate supplementation to the Ni-deprived rats. Also, dietary Ni affected several plasma amino acids important in one-carbon metabolism (e.g., Ni deprivation increased the plasma concentrations of glycine and serine). This study shows that dietary Ni, folate, and their interaction can affect variables associated with one-carbon metabolism. This study does not show a specific site of action of Ni but it indicates that Ni may be important in processes related to the vitamin B12-dependent pathway in methionine metabolism, possibly one-carbon metabolism.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed1999

Liver transplantation for methylmalonic acidaemia.

UNLABELLED: The outcome for children with severe forms of methylmalonic acidaemia remains poor. Patients have recurrent episodes of metabolic decompensation; many have neurodevelopmental complications and the mortality is high. Long-term survivors develop chronic renal failure. Because of the poor prognosis, transplantation has been considered. In young patients with early onset disease, liver transplantation might prevent complications and, for those in end-stage renal failure, kidney transplantation could be combined with that of the liver. The results of liver transplantation in the early onset patients have generally been disappointing. In particular there appears to be a high risk of neurological complications. The optimal management of those in end-stage renal failure has not yet been determined although combined liver and kidney transplantation has been successful. CONCLUSION: The role of transplantation in methylmalonic acidaemia has yet to be established and follow up of all patients who are considered for transplantation is essential.

Adolescent↗
PubMed2000

Enzyme-activity mutants in Mus musculus. I. Phenotypic description and genetic characterization of ethylnitrosourea-induced mutations.

The specific activity of erythrocyte enzymes was measured to detect gene mutations in F(1)-offspring of male mice treatment with different doses (80, 160, or 250 mg/kg body weight) of ethylnitrosourea (ENU). Altogether 13,230 offspring were screened for 10 enzyme activities. Mutants with reduced activity as well as mutants with enhanced activity were found. Of the 36 independently observed mutations, 20 were homozygous lethal. Genetic and biochemical characterizations were routinely performed. These mutants provide insight into the mechanism of ENU mutagenesis and can serve as models for structure-function studies of the corresponding enzymes.

Animals↗
PubMed2002

Progressive neurologic disability in methylmalonic acidemia despite transplantation of the liver.

UNLABELLED: Methylmalonic acidemia unresponsive to cobalamin is often fatal in infancy. Patients have been considered candidates for hepatic transplantation and experience has been that the procedure eliminates the life-threatening episodes of ketoacidosis that characterize this disease. CONCLUSION: experience with a 24-year-old patient treated with hepatic transplantation indicates that this procedure does not prevent progressive renal failure and neurologic dysfunction.

Acute Kidney Injury↗
PubMed2005

Allosteric mechanisms in ACT domain containing enzymes involved in amino acid metabolism.

An important sequence motif identified by sequence analysis is shared by the ACT domain family, which has been found in a number of diverse proteins. Most of the proteins containing the ACT domain seem to be involved in amino acid and purine synthesis and are in many cases allosteric enzymes with complex regulation enforced by the binding of ligands. Here we explore the current understanding of the ACT domain function including its role as an allosteric module in a selected group of enzymes. We will further describe in more detail three of the proteins where some understanding is available on function and structure: i) the archetypical ACT domain protein E. coli 3PGDH, which catalyzes the first step in the biosynthesis of L-Ser, ii) the bifunctional chorismate mutase/prephenate dehydratase (P-protein) from E. coli, which catalyzes the first two steps in the biosynthesis of L-Phe, and iii) the mammalian aromatic amino acid hydroxylases, with special emphasis on phenylalanine hydroxylase, which catalyzes the first step in the catabolic degradation of L-phenylalanine (L-Phe). The ACT domain is commonly involved in the binding of a small regulatory molecule, such as the amino acids L-Ser and L-Phe in the case of 3PGDH and P-protein, respectively. On the other hand, for PAH, and probably for other enzymes, this domain appears to have been incorporated as a handy, flexible small module with the potential to provide allosteric regulation via transmission of finely tuned conformational changes, not necessarily initiated by regulatory ligand binding at the domain itself.

Allosteric Regulation↗