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J Knudsen

Publications and source records attributed to J Knudsen.

162 records · Page 9Linked to original sources

Urinary pseudouridine and beta-aminoisobutyric acid in patients with low grade urothelial tumours. Relations between excretion and tumour recurrence.

The simultaneous 24 hours excretion of pseudouridine and beta-aminoisobutyric acid in the urine from patients treated for low grade urothelial tumours has been determined and related to tumour recurrence inside of 6 months after the determinations. The results of 53 assays in 39 patients without clinical signs of recurrence at the time of the detrmination showed a high excretion of pseudouridine in 53% and of beta-aminoisobutyric acid in 28.5% of the assays. Recurrences appeared more often after a high urinary pseudouridine (53.5%) than after a low, but the difference was not statistically significant (p more than 0.05) and more often after a low urinary beta-aminoisobutyric acid (52.5%) than after a high (p less than 0.01). The highest incidence of recurrence was in patients with a simultaneously high urinary pseudouridine and a low urinary beta-aminoisobutyric acid. Seventy per cent of these excretion patterns were from patients, who developed a recurrence before 6 months (p less than 0.002).

Adult↗

A study on the clinical significance of urinary beta-aminoisobutyric acid in patients with urothelial tumours.

Urinary beta-aminoisobutyric acid (beta-AIB) has been measured in 141 patients with urothelial tumours and 60 controls. Ninetyone of the patients have been followed-up for an average period of about 2 years, which included many determinations of the beta-AIB excretion. Thirtysix patients died during the control periods. Urinary beta-AIB was found to be significantly correlated to the grade of tumour cell dysplasia, but not to the clinical tumour stage. The treatment had no major influence on the excretion. Characteristic changes in the excretion preceding high-grade tumour recurrences are demonstrated. Autopsy findings with tumour tissue in the urinary tract and distant metastases were significantly correlated to a low urinary beta-AIB in the terminal phase of the disease. The results are discussed in relation to the degradation of thymine, the dual origin of beta-AIB and the tumour-host metabolism. It is concluded, that urinary beta-AIB can contribute to the graduation of malignancy, but is not valuable as a general screening procedure for urothelial cancer.

Aged↗

Revision of the amino acid sequence of human heart fatty acid-binding protein.

Cardiac-type fatty acid-binding protein (cFABP) from human heart muscle of three individuals was isolated and characterized as pI 5.3-cFABP. The proteins were structurally analyzed by tryptic peptide mapping, application of plasma desorption time-of-flight mass spectrometry and amino acid sequencing. All three preparations of human heart FABP, having 132 amino acids, differed from the published sequence [Offner et al. Biochem J 251: 191-198, 1988] in position 104, where Leu is found instead of Lys, and in position 124, where Cys is found instead of Ser.

Amino Acid Sequence↗

Acyl-CoA-binding protein (ACBP) and its relation to fatty acid-binding protein (FABP): an overview.

Acyl-CoA-binding protein is a 10 Kd protein which binds medium- and long-chain acyl-CoA esters with high affinity. The concentration in liver is 2-4 times the acyl-CoA concentration. ACBP has much greater affinity for acyl-CoA than FABP. FABP from bovine heart and liver is unable to compete with multilamellar liposomes, Lipidex and microsomal membrane in binding acyl-CoA esters, whereas ACBP effectively extracts acyl-CoA from all those sources. Previously published results on the effect of FABP on acyl-CoA metabolism need to be reevaluated due to possible contamination with ACBP. Recently it was discovered that ACBP is identical to a putative neurotransmitter diazepam binding inhibitor. The possibility therefore exists that ACBP has more than one function.

Acyl Coenzyme A↗

Genome organization and expression of the rat ACBP gene family.

Acyl-CoA-Binding Protein (ACBP)/Diazepam-Binding Inhibitor (DBI) is a 10 kD protein which has been implicated in a surprisingly large number of biochemical functions. We have unambiguously demonstrated that ACBP binds acyl-CoA esters with high affinity and in vivo functions as an acyl-CoA ester pool former. We have molecularly cloned and characterized the rat ACBP gene family which comprises one expressed and four processed pseudogenes. One of these was shown to exist in two allelic forms. A comprehensive computer-aided analysis of the promoter region of the expressed ACBP gene revealed that it exhibits all the hallmarks of typical housekeeping genes. In addition, the promoter region harbors a number of potential tissue specific cis-acting elements that may in part regulate the level of ACBP expression in specialized cells.

Acyl Coenzyme A↗

The function of acyl-CoA-binding protein (ACBP)/diazepam binding inhibitor (DBI).

Acyl-CoA-binding protein has been isolated independently by five different groups based on its ability to (1) displace diazepam from the GABAA receptor, (2) affect cell growth, (3) induce medium-chain acyl-CoA-ester synthesis, (4) stimulate steroid hormone synthesis, and (5) affect glucose-induced insulin secretion. In this survey evidence is presented to show that ACBP is able to act as an intracellular acyl-CoA transporter and acyl-CoA pool former. The rat ACBP genomic gene consists of 4 exons and is actively expressed in all tissues tested with highest concentration being found in liver. ACBP consists of 86 amino acid residues and contains 4 alpha-helices which are folded into a boomerang type of structure with alpha-helices 1, 2 and 4 in the one arm and alpha-helix 3 and an open loop in the other arm of the boomerang. ACBP is able to stimulate mitochondrial acyl-CoA synthetase by removing acyl-CoA esters from the enzyme. ACBP is also able to desorb acyl-CoA esters from immobilized membranes and transport and deliver these for mitochondrial beta-oxidation. ACBP efficiently protects acetyl-CoA carboxylase and the mitochondrial ADP/ATP translocase against acyl-CoA inhibition. Finally, ACBP is shown to be able to act as an intracellular acyl-CoA pool former by overexpression in yeast. The possible role of ACBP in lipid metabolism is discussed.

Acyl Coenzyme A↗