PubMed Health⌕ Search

Biomedical subjects

G Steen

Publications and source records attributed to G Steen.

At least 55 records · Page 3Linked to original sources
PubMed1980

The early recognition of the 21-hydroxylase deficiency variety of congenital adrenal hyperplasia.

The urinary steroids excreted by three newborn infants with 21-hydroxylase deficiency and by 15 healthy newborns aged two days have been compared after analysis by gas liquid chromatography (GLC). The identity of each steroid was carefully checked by gas chromatography/mass spectroscopy (GC-MS). The enzyme deficiency leads to the elevated excretion of urinary precursor metabolites, mainly 3alpha,17alpha,20alpha-trihydroxy-5beta-pregnan, 3alpha,17alpha,20alpha-trihydroxy-5beta-pregnan-11-one and 3alpha,17alpha-dihydroxy-5beta-pregnan-20-one. In the search for a quick and firm confirmation of suspected 21-hydroxylase deficiency in a newborn baby by means of a GLC-profile of urinary steroids, most attention has up to now been paid to 3alpha,17alpha,20alpha-trihydroxy-5beta-pregnan. However, 3alpha,17alpha-dihydroxy-5beta-pregnan-20-one is a better indicator, as it enables one to confirm the existence of this disease soon after birth directly from the GLC-profile without further analyses by GC-MS.

Adrenal Hyperplasia, Congenital↗
PubMed1980

3-hydroxydecanedioic acid and related homologues: urinary metabolites in ketoacidosis.

Urine from patients with ketoacidosis was found to contain a number of aliphatic 3-hydroxy dicarboxylic acids. The acids were purified by silicic acid chromatography and their structures determined by gas chromatography-mass spectrometry of different derivatives. The major compound was 3-hydroxydecanedioic acid. Minor compounds were 3-hydroxyoctanedioic acid, 3-hydroxyoctenedioic acid, 3-hydroxydecenedioic acid, 3-hydroxydodecanedioic acid, 3-hydroxydodecenedioic acid, 3-hydroxytetradecenedioic acid, and 3-hydroxytetradecadienedioic acid. The excretion of 3-hydroxydecanedioic acid correlated positively with the excretion of hexanedioic acid, another metabolite constantly found in ketoacidosis (Pettersen et al., Clin. Chim. Acta 38: 17-24, 1972). We suggest that the 3-hydroxy dicarboxylic acids are formed from fatty acids by a combination of omega-oxidation and incomplete beta-oxidation.

Acidosis↗
PubMed1979

Urinary metabolites of cis-9,10-methylene octadecanoic acid. cis-3,4-Methylene hexanedioic acid and related compounds.

cis-3,4-Methylene hexanedioic acid has been discovered in human urine. It has been isolated and identified by mass spectrometry and synthesis. The daily excretion in nine subjects on a free diet was 88 mumol/day (range, 32 to 144 mumol/day). cis-3,4-Methylene hexanedioic acid was given orally to a rat. About 90% of the dose was recovered unchanged in the urine within 24 h. Intragastric administration of cis-9,10-methylene [9,10-3H2]octadecanoic acid to rats gave four labeled urinary metabolites. The major one was cis-3,4-methylene hexanedioic acid, the others were 2,3-methylene pentanedioic acid and isomers of methylene heptanedioic acid and methylene octanedioic acid. Within 72 h, about 40% of the administered radioactivity could be recovered from the urine and another 40% from the carcass. About 20% of the recovered radioactivity was found to be water. Of the radioactivity administered to rats orally as cis-9,10-methylene [9,10-3H2]octadecanoic acid methyl ester, about 50% could be recovered from the lymph of the thoracic duct within 9 h. Intraperitoneal administration of cis-9,10-methylene octodecanoic acid methyl ester to rats gave the same metabolites. Of the given amount, 50 mol % could be recovered from the urine as cis-3,4-methylene hexanedioic acid and 19 mol % as homologues within 38 days.

Adult↗
PubMed1979

A biclonal origin of two monoclonal proteins, IgG3(kappa) and IgA1(lambda), from a single patient.

The cellulose acetate electrophoretic pattern of the serum from patient Sik disclosed two distinct peaks, representing two monoclonal proteins. On immunoelectrophoresis the two M-components were found to differ in heavy chain class as well as in light chain type, IgG3(kappa) and IgA1(lambda). Serum immunoglobulin levels remained relatively constant over a period of 7 years and no clinical symptoms of a malignant deterioration occurred. It was found that the isolated M-components did not share idiotypic antigenicity. Bone marrow cells synthesizing the monoclonal proteins were identified by means of the immunofluorescent technique using isotypic as well as idiotypic antisera. Two distinct monoclonal cell populations were observed, containing either the IgG3(kappa) or the IgA1(lambda) monoclonal protein. The alpha 1-chain belonged to the VHIII subgroup, whereas the gamma 3-chain was found to be blocked. Subsequent sequence determination showed the gamma 3-chain to belong to the VHIII subgroup. It was concluded that the two M-components in the serum of patient Sik resulted from two independent neoplastic transformations.

Aged↗
PubMed1979

Urinary excretion of thymine and uracil in a two-year-old child with a malignant tumor of the brain.

A two-year-old boy with a malignant tumor of the brain (medulloblastoma) excreted large amounts of thymine and uracil in his urine. The excretion was related to progress and regress of the disease, and reached a maximum of 3.0 mol of thymine per mole of creatinine and 2.6 mol of uracil per mole of creatinine. The excretion by 20 apparently normal children was less than 0.01 mol/mol of creatinine for each of the two pyrimidines. Three children with brain tumors, two with leukemias, and one with neuroblastoma were also studied; two of them had a moderate increase in urinary pyrimidine excretion, but only up to 0.07 mol/mol of creatinine. The activity of dihydrouracil dehydrogenase (NADP+) (EC 1.3.1.2) in cultured fibroblasts from the patient was somewhat lower than in control fibroblasts. The tumor was considered to be the likely cause of the increased excretion of pyrimidines, but an impaired degradation of pyrimidines in the liver could not be ruled out.

Adolescent↗
PubMed1978

3-methylglutaconic aciduria: report on a sibship with infantile progressive encephalopathy.

Choreoathetosis, spastic parapareses, dementia and optic atrophy were the main clinical features in a sibship with progressive encephalopathy of late onset. The urine contained constantly elevated amounts of 3-methylglutaric and 3-methylglutaconic acids. The identity of these metabolites was confirmed by synthesis and mass spectrometry. On leucine loading, the excretion of the metabolites was elevated.

Amino Acid Metabolism, Inborn Errors↗
PubMed1978

A comparison of glucagon, gastric inhibitory peptide, and secretin on gallbladder function, formation of bile, and pancreatic secretion in the cat.

The effects of glucagon, gastric inhibitory peptide (GIP), and secretin on the concentrating mechanism and the motility in the feline gallbladder have been studied in vivo. A technique by which the gallbladder in situ was perfused by an electrolyte solution made possible a simultaneous study of the motility and of the net transport of water and electrolytes across the gallbladder wall. Secretin (0.6 microgram per kg/h) was found to abolish the net absorption of water, Na+, and HCO3- and strongly reduce the net absorption of K+ and Cl-, whereas neither glucagon (1--20 microgram per kg/h) nor GIP (1--30 microgram per kg/h) was found to significantly influence the concentrating function of the gallbladder. The motility of the gallbladder was not influenced by the peptides. The formation of bile and pancreatic secretion was not changed by glucagon or GIP, whereas secretin had a potent effect.

Animals↗
PubMed1978

Effects of intravenous vasoactive intestinal peptide (VIP) on gallbladder function in the cat.

The influence of vasoactive intestinal peptide (VIP) on the concentrating mechanism and the motility in the feline gallbladder has been studied in vivo. A perfusion technique made possible a simultaneous study of the motility and of the net transport of water and electrolytes across the gallbladder wall. It was found that an intravenous infusion of VIP relaxes the gallbladder and induces a net fluid secretion into its lumen. The net absorption of chloride ions was markedly reduced, whereas the net transport of sodium, potassium, and bicarbonate was reversed from an absorption into a secretion. Owing to the presence of VIP-containing nerve fibers in the gallbladder wall, a physiological significance for the secretory gallbladder response to VIP is suggested.

Animals↗
PubMed1977

Intermittently progressive dyskinetic syndrome in glutaric aciduria.

A case of glutaric aciduria, a recently discovered inborn error of tryptophan-lysine metabolism, is reported. Development was normal during the first year of life. Signs of dyskinesia and dystonia associated with developmental regression occurred twice during gastrointestinal disease. By two years of age, a dystonic syndrome with a severe motor and language disability had resulted.

Amino Acid Metabolism, Inborn Errors↗
PubMed1977

On the enzymic defects in hereditary tyrosinemia.

The activity of the enzyme porphobilinogen synthase (EC 4.2.1.24) in erythrocytes from patients with hereditary tyrosinemia was less than 5% of that in a control group and the activity in liver tissue was less than 1% of the reported normal activity. Urine from patients with hereditary tyrosinemia contained an inhibitor that was isolated and identified as succinylacetone (4,6-dioxoheptanoic acid) by gas/liquid chromatography-mass spectrometry. Fresh urine samples contained succinylacetoacetate (3,5-dioxooctanedioic acid) as well as succinylacetone. The inhibition of porphobilinogen synthase explains the high excretion of 5-aminolevulinate observed in hereditary tyrosinemia. Succinylacetone and succinylacetoacetate presumably originate from maleylacetoacetate or fumarylacetoacetate, or both, and their accumulation indicates a block at the fumarylacetoacetase (EC 3.7.1.2) step in the degradation of tyrosine. We suggest that the severe liver and kidney damage in hereditary tyrosinemia may be due to the accumulation of these tyrosine metabolites and that the primary enzyme defect in hereditary tyrosinemia may be decreased activity of fumarylacetoacetase.

4-Hydroxyphenylpyruvate Dioxygenase↗
PubMed1976

Organic acids in urine from human newborns.

The pattern of organic acids in urine from 15 normal newborn infants was investigated by gas chromatography/mass spectrometry of trimethylsilylated derivatives. The urine contains large amounts of succinic, fumaric, 2-ketoglutaric, and 3-hydroxy-3-methylglutaric acids, which are all fairly small components of urine from adults. On the other hand, hippuric acid is a small component in the urine from newborn infants, but a large component later in life. An additional number of differences can be seen. Some previously unrecognized aliphatic dicarboxylic acids were also observed, which are present to some extent in urine from adults.

Chromatography, Gas↗
PubMed1976

Structure of some aliphatic dicarboxylic acids found in the urine of an infant with congenital lactic acidosis.

Gas chromatography/mass spectrometry was used to identify a series of acids in urine and serum from a child who died 26 h after birth in severe metabolic acidosis with high lactate excretion. cis-5-Decene-1, 10-dioic acid and cis-5-dodencene-1, 12-dioic acid were synthesized and used as references. The following acids were found: hexane-1,6-dioic acid, octane-1,8-dioic acid, decane-1,10-dioic acid, dodecane-1,12-dioic acid, cis-5-decene-1,10-dioic acid, cis-5-dodecen-1,12-dioic acid, cis-5-tetradecene-1,14-dioic acid, trans-3-decene-1,10-dioic acid, and trans-3-dodecene-1,12-dioic acid. The concentration of C6 to C14 acids in the patient's urine was 3.7 mol/mol of creatinine; it was less than 0.2 mol/mol of creatinine in eight normal newborns and approximately 0.1 mol/mol of creatinine in a case of fructose-1,6-biphosphatase deficiency with lactic acidosis. 5-cis-Dodecenedioic acid was present in highest concentration: 1 mol/mol of creatinine in urine and 61 mumol/liter in serum. We propose that impaired beta-oxidation, probably at the acyl-CoA-dehydrogenase step, resulted in the formation of the observed acids. The parents were consanguineous, and a sibling died with the same clinical picture, which suggests a genetic defect.

Acidosis↗
PubMed1976

Aliphatic medium chain tricarboxylic acids in rat urine.

Three aliphatic tricarboxylic acids have been found in rat urine. They have been identified as 6-carboxy-5-undecenedioic acid, 6-carboxy-5-dodecenedoic acid, and 6-carboxy-5-tridecenedioic acid. The carbon skeleton structure was determined by mass spectra of the hydrogenated methyl esters. The double bond position was determined after osmium tetroxide oxidation followed by trifluoroacetylation and mass spectrometry and by infrared spectrometry. The compounds were present in the urine when the rats were fed on pellets but disappeared when they received sucrose and water. The acids were not present in the pellets, and a metabolic relation to compounds of longer chain length, possibly mycolic acids, is likely.

Animals↗