Search PubMed⌕ Search

Biomedical subjects

L Sweetman

Publications and source records attributed to L Sweetman.

At least 145 records · Page 8Linked to original sources
PubMed1978

Abnormal metabolites of isoleucine in a patient with propionyl-CoA carboxylase deficiency.

A number of previously unrecognized abnormal metabolites have been identified and quantitated in the urine of a patient with an inherited deficiency of propionyl-CoA carboxylase. These included the isoleucine metabolites 2-methyl-3-hydroxybutyric acid and 2-methylacetoacetic acid. These isomers 3-hydroxyvaleric acid and 3-oxovaleric acid were found, which may be products of the condensation of propionyl-CoA with acetyl-CoA catalyzed by 3-oxoacyl-CoA thiolases. Following a load of isoleucine, 2-methylbutyrylglycine was identified. This metabolite has not previously been observed in man.

Acetoacetates↗
PubMed1978

Tyrosinemia associated with perinatal infection with cytomegalovirus.

A premature infant presented with elevated concentrations of tyrosine in blood and urine, evidence of hepatocellular damage, demineralization of the bones, and a renal Fanconi syndrome. This is the clinical picture found in hereditary tyrosinemia. The infant also had a perinatal infection with cytomegalovirus.

Cytomegalovirus Infections↗
PubMed1978

A distinct human variant of hypoxanthine-guanine phosphoribosyl transferase.

A variant form of hypoxanthine-guanine phosphoribosyl transferase has been found in a neurologically normal pediatric patient who presented with hematuria an episodes of oliguria and azotemia. The level of erythrocyte enzyme activity was 3% of normal. Electrophoretic mobility was more rapid than normal. The Km for hypoxanthine was approximately ten times normal. Immunochemical analysis indicated that the variant enzyme cross reacted with antibody to normal HPRT. A system is described for the systematic characterization of a variant HPRT.

Antibodies↗
PubMed1978

Simple sensitive microbioassay for adenine arabinoside and hypoxanthine arabinoside in human plasma.

Previous methods using low- or high-pressure liquid chromatography and UV absorbance for quantitation of arabinosides in plasma can practically detect only >/=200 ng of adenine arabinoside and >/=100 ng of hypoxanthine arabinoside per ml, and they require expensive equipment and expert technical assistance. We describe in this report a simple quantitative microbioassay for arabinosides in human plasma based on their ability to inhibit the cytopathic effect of vaccinia virus in an adenosine deaminase-free cell culture system. Using prior separation of nucleosides in plasma by thin-layer chromatography, followed by the microbioassay, we quantitated adenine arabinoside with a sensitivity of approximately 4 ng/ml and hypoxanthine arabinoside at approximately 625 ng/ml. This assay method is simple, sensitive, and reproducible, requires small plasma samples, measures biological activity, and is adaptable to routine use. It is an important tool for evaluating the pharmacology of adenine arabinoside and Ara-AMP in patients in current clinical trials.

Humans↗
PubMed1977

Deficiency of propionyl-Co A carboxylase and methylcrotonyl-Co A carboxylase in a patient with methylcrotonylglycinuria.

The enzymes 3-methylcrotonyl-CoA carboxylase and propionyl-CoA carboxylase were studied in fibroblasts derived from a patient with 3-methylcrotonylglycinuria and from control individuals. There was a parallel defect in the activities of both enzymes in extracts of the cells of the patient. Supplementation with biotin of the medium in which the cells were grown restored the activity of both carboxylases to the normal range. Kinetic analysis of the activities of the carboxylases obtained from cells grown in biotin revealed KM values for each enzyme that approximated normal. These data indicate that the primary defect in this patient is in the enzyme holocarboxylase synthetase which is responsible for activating biotin and transferring it to the apocarboxylase proteins.

Amino Acid Metabolism, Inborn Errors↗
PubMed1977

EEG correlations with biochemical abnormalities in Reye syndrome.

A patient with Reye syndrome was studied throughout the course of the illness with continuous EEG monitoring, and these patterns were correlated with serial determinations of serum ammonia and short-chain fatty acid concentrations. There was high correlation between degree of EEG abnormality, clinical symptoms, and elevations of the short-chain fatty acids, while serum ammonia concentrations correlated poorly with the EEG and with the clinical state.

Ammonia↗
PubMed1977

Propionyl-CoA carboxylase deficiency in a patient with biotin-responsive 3-methylcrotonylglycinuria.

The abnormal metabolites 3-hydroxypropionic acid (1.6-4.0 mg/day) and methylcitric acid (3.7-5.8 mg/day) were identified and quantitated in the urine of a patient in whom biotin-responsive 3-methylcrotonylglycinuria and deficiency of 3-methylcrotonyl-CoA carboxylase had previously been documented. The level of excretion of these metabolites was in the lower range of those found in patients with propionic acidemia in whom there is a deficiency of propionyl-CoA carboxylase. The activity of this enzyme in fibroblasts derived from the patient and grown in media low in biotin was 4% of normal. This is the range of patients with propionyl-CoA carboxylase deficiency. Documented deficiency in this patient of two carboxylase, both of which contain biotin, suggests that the primary defect is in the metabolism of biotin.

Biotin↗
PubMed1975

Hyperglycinemia and propionyl coA carboxylase deficiency and episodic severe illness without consistent ketosis.

Propionyl CoA carboxylase deficiency was found in a 7-month-old boy who presented with attacks of vomiting, anorexia, weight loss, weakness, and hypotonia. He failed to thrive and had generalized seizures. He had propionic acidemia and hyperglycinemia; these are the manifestations of the ketotic hyperglycinemia syndrome. However, ketonuria was not a consistent part of his clinical picture, and he had at least two episodes of acute overwhelming illness, the latter one fatal, in which ketones were never found in the urine. Large amounts of pyrrolidone carboxylic acid were found in body fluids.

Acidosis↗
PubMed1975

Short-chain organic acidemia and Reye's syndrome.

Short-chain fatty acids were determined prior to therapy in seven patients with Reye's syndrome. Elevated concentrations of propionate, butyrate, and isobutyrate were found in all patients. Isovalerate concentrations were high in three patients. In view of the fact that the administration of certain short-chain fatty acids to experimental animals results in coma, electroencephalographic changes, and fatty accumulation in the viscera, the elevations of short-chain fatty acid concentrations observed in the present study suggest that these fatty acids may play a role in the clinical manifestations of Reye's syndrome.

Adolescent↗