The increased urinary excretion of methylmalonic acid in vitamin B12 deficiency has attracted attention and several studies have suggested that it has clinical value as a test of vitamin B12 deficiency (Cox and White, 1962; Bashir, Hinterberger, and Jones, 1966). Chromatographic methods of estimation have been used but are either time consuming or only semiquantitative over a narrow range of me...

The authors provide an overview of the hereditary methylmalonic acidemias, a group of metabolic disorders with varied clinical presentations. This includes the most severe form of L-methylmalonyl-CoA mutase deficiency, termed mut(o) methylmalonic acidemia, which, together with the less severe deficiencies of L-methylmalonyl-CoA mutase, are the most common causes of methylmalonic acidemia. They ...

We describe a gas-chromatographic procedure for determining methylmalonic acid in serum and urine. The sample is acidified and the compound is extracted from it with diethyl ether, derivatized with N,Obis(trimethylsilyl)trifluoroacetamide, and gas chromatographed. Precision and sensitivity of the method were verified by recovery studies and by comparing the resultswith those foran established p...

Two human subjects were given separate oral doses of sodium [2H6]isobutyrate and [methyl-2H3]thymine and the labelling patterns of urinary metabolites were determined. Ingestion of deuterated isobutyrate resulted in the excretion of 2H5-labelled S-3-hydroxyisobutyric acid, formed on the direct catabolic pathway, and of S- and R-[2H4]-3-hydroxyisobutyric acids, formed by the reduction of S- and ...

OBJECTIVE Methylmalonic acidemia is one of the inborn errors of metabolism resulting in the accumulation of acylcarnitine in blood and increased urinary methylmalonic acid excretion. This disorder can have symptoms, such as neurological and gastrointestinal manifestations, lethargy, and anorexia. MATERIALS & METHODS The patients who were diagnosed as methylmalonic acidemia in the Neurology De...

PURPOSE To present the CT and MR findings in children with propionic and methylmalonic acidemia. METHODS Twenty-three new patients with methylmalonic and 20 with propionic acidemia were examined with CT and/or MR of the brain. In total 52 CT and 55 MR studies were done. Twenty-six previously published cases were also reviewed. RESULTS The findings were similar in the two syndromes. During t...

I s nanoscience the “first full embodiment of post-academic science”? Have many of the traditional core values of publicly funded university science been eroded to the point where they are now “part of a scientific mythology”? And is it “morally bankrupt” to draw a distinction between ‘pure’ and ‘applied’ science? These claims, which were all made in a recent commentary in Nature Nanotechnology...

organic acidemias, also known as organic acidurias, are a group of disorders characterized by increased excretion of organic acids in urine. they result primarily from deficiencies of specific enzymes in the breakdown pathways of amino acids or from enzyme deficiencies in beta oxidation of fatty acids or carbohydrate metabolism. organic acids also are found in the urine of some patients with mi...

background: urinary organic acids are water-soluble intermediates and end products of the metabolism of amino acids, carbohydrates, lipids, and a number of other metabolic processes. in the hereditary diseases known as organic acidurias, an enzyme or co-factor defect in a metabolic pathway leads to the accumulation and increased excretion of one or more of these acidic metabolites. gas chromato...