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Biomedical subjects

O Borud

Publications and source records attributed to O Borud.

At least 19 recordsLinked to original sources
PubMed2000

Regulation of gamma-glutamyltransferase in cisplatin-resistant and -sensitive colon carcinoma cells after acute cisplatin and oxidative stress exposures.

Glutathione plays an important role in drug resistance of tumor cells and in their ability to resist oxidative stress. Improved salvage of glutathione can be obtained through increased activity of gamma-glutamyltransferase (GGT), which is of importance in the maintenance of cellular glutathione homeostasis. We investigated the regulation of GGT in 2 cisplatin-resistant and 1 cisplatin-sensitive colon carcinoma cell lines. Enzyme activity was induced in all 3 cell lines after acute exposure to cisplatin. The elevation was significantly higher in sensitive cells (3.3-fold) than in resistant (1.6- to 1.7-fold) cells. Exposure of cells to oxidative stress generated by menadione also resulted in enzyme induction but only in cisplatin-sensitive cells. Addition of anti-oxidants had different effects on the 2 inductions: N-acetylcysteine blocked the induction of both cisplatin and menadione, whereas catalase and glutathione-ester blocked only the menadione induction. Glutathione depletion alone was not sufficient to induce GGT in these cells. The data show that GGT is regulated by multiple mechanisms during anti-tumor drug treatment and oxidative stress and that reactive oxygen species were involved in the menadione, but not cisplatin, induction of the enzyme.

Antineoplastic Agents↗
PubMed1994

Lactate and pyruvate concentrations in capillary blood from newborns.

Using high pressure liquid chromatography on strong cation exchange column, we analyzed capillary blood from 141 healthy full-term newborns for lactate and pyruvate concentrations. Total range of lactate was 367-3245 mumol/l and reference interval (mean +/- 2 SD) was 260-2212 mumol/l. Total range of pyruvate was 10-141 mumol/l and reference interval (10th/90th percentile) was 12-71 mumol/l.

Adolescent↗
PubMed1994

Aspartylglucosaminuria in northern Norway: a molecular and genealogical study.

Aspartylglucosaminuria (AGU, McKusick 208400) is an autosomal recessive lysosomal storage disorder. Ninety percent of all patients are from Finland and only sporadic cases have been reported from elsewhere. In northern Norway, however, nine patients from seven families have been diagnosed with AGU. All these Norwegian patients were homozygous for the most prevalent Finnish AGU mutation (AGUFin) and show the polymorphism uniquely associated with AGUFin in Finland. Genealogical investigation of nine parents proved Finnish ancestry in all pedigrees. Therefore, AGU in Norway most likely resulted from immigration of Finnish carriers. These Finnish immigrants originated mostly from the Tornio valley area in northern Finland in a continuous immigration movement from 1700 to 1900. The majority settled in the western part of northern Norway, leading to a "cluster" of AGU in that particular area. The Finnish immigrants intermixed considerably with Lapps and these two ethnic origins should thus be considered as high risk groups for AGUFin in northern Norway.

Acetylglucosamine↗
PubMed1991

[Mitochondrial diseases. Diagnostic light and electron microscopic changes in muscle biopsies from patients with mitochondrial myopathy].

Mitochondrial myopathy can be caused by several metabolic defects in the mitochondria. Cells with high levels of oxidative metabolism, such as skeletal muscle, myocardium and brain cells, are particularly vulnerable to these defects. We describe the structural changes in muscle biopsies from 49 patients with mitochondrial myopathy. The younger patients were often symptom-free, but the possibility of a genetic defect was suggested by the family history. "Ragged-red fibres" were found in 10% of the biopsies. Typical paracrystalline inclusions were seen in the mitochondria of the oldest patients. Electron-lucent matrix and increased thickness of the inner membranes of the mitochondria in particular were found in the younger patients. Disorganization of cristae, with cristolysis and unfolding of the cristae was also found. We suggest that structural mitochondrial changes in mitochondrial myopathy constitute a stepwise process and that the mitochondrial alterations of the cristae may represent an early stage in the morphogenesis of mitochondrial disease.

Age Factors↗
PubMed1991

Mitochondrial myopathy in Marinesco-Sjögren syndrome.

Myopathy represents one of the major features of Marinesco-Sjögren syndrome (MSS). Seven patients with MSS from three different families were studied with morphological and neurophysiological methods. In two patients ragged-red fibres were found after Gomori trichrome staining. Transmission electron microscopy (EM) showed that subsarcolemmal accumulation of abnormal mitochondria regularly occurred and in one patient paracrystalline inclusion bodies were found. The EMG showed myopathic changes while the nerve condition velocities were normal. A delayed normalization of exercised-induced hyperlactatemia was noted. These findings show that mitochondrial myopathic changes are present in MSS.

Adolescent↗
PubMed1990

Early mitochondrial changes in chronic progressive ocular myopathy.

Two sisters with chronic progressive external ophthalmoplegia (CPEO) and their in all 7 healthy children were investigated. Both ophthalmoplegic patients had histopathological changes typical of mitochondrial myopathy. The same type of muscular pathology was also found among the healthy children. The most common muscular changes were subsarcolemmal accumulation of pathological mitochondria, including vacuoles, abnormal cristae and sometimes also inclusion bodies. Biochemical studies showed partial complex III deficiency, with low succinate-cytochrome c reductase activity in 1 of the ophthalmoplegic patients. These findings suggest that CPEO is a slowly progressive muscle disease, starting early in life. The widespread occurrence among the children may indicate maternal inheritance.

Adolescent↗
PubMed1989

Cystathioninuria in Down's syndrome.

Secondary cystathioninuria is associated with various pathological conditions (Gjessing, 1963; Gjessing & Mauritzen, 1965; Endres & Wuttge, 1978). In many cases, cystathioninuria has been associated with mental retardation (Harris et al., 1959; Robb et al., 1984). As far as the authors know, cystathioninuria has not previously been described in Down's syndrome. In 1981, in the author's institution for the mentally retarded, all patients with Down's syndrome were screened with regard to aminoaciduria, using thin layer chromatography. In the course of this process, a case of cystathioninuria was discovered. The results are presented in detail.

Adult↗
PubMed1989

Pre-eclampsia--a mitochondrial disease?

Mitochondrial dysfunction is a newly found group of inborn errors of metabolism in which there is a failure in the aerobic energy production. Disorders of mitochondrial metabolism exhibit a wide range of clinical symptoms which are related to the nature, severity and tissue distribution of the metabolic defect. Most reported cases are published in the neurological literature. In this report we describe for the first time a family with mitochondrial dysfunction with a high incidence of pre-eclampsia/eclampsia. The diagnosis of a mitochondrial disorder is verified by electronmicroscopic, electromyographic, histochemical and biochemical examinations. During pregnancy, the energy demand is increased due to both fetal and maternal requirements. A mitochondrial dysfunction, clinically symptomless in the non-pregnant state, may therefore become manifest during pregnancy. Characteristic features of pre-eclampsia such as disturbed ion transport, disturbed prostaglandin synthesis, vasoconstriction, platelet aggregation and hyperuricemia may be explained by mitochondrial dysfunction.

Adult↗
PubMed1982

Normal 2-aminobutyrate oxidation and increased valine oxidation in fibroblasts deficient in pyruvate dehydrogenase.

Human skin fibroblasts deficient in pyruvate dehydrogenase and five normal control strains were incubated with one of the following labelled substrates: DL-[1-14C]-2-amino-n-butyric acid, DL-[3-14C]-2-amino-n-butyric acid, L-[1-14C]leucine, L-[1-14C]valine, L-[1-14C]alanine, and [1-14C]pyruvate. The rate of 14CO2-production in the deficient cells was normal from 2-aminobutyrate and leucine, increased from valine, and decreased from alanine and pyruvate. These results indicated that in human skin fibroblasts the decarboxylation of 2-oxobutyrate is catalysed by an enzyme system different from the pyruvate dehydrogenase complex.

Aminobutyrates↗
PubMed1981

Biochemical and clinical studies of Friedreich's ataxia.

A series of biochemical tests aimed at elucidating the fundamental cause has been applied to 20 patients with Friedreich's ataxia. Special emphasis was placed upon pyruvate metabolism. The results demonstrate no precisely identifiable defect in the metabolism of pyruvate but indicate an abnormality in glucose uptake and metabolism.

Adolescent↗
PubMed1980

Combined iminoglycinuria and cystine- and dibasic aminoaciduria in patients with propionic acidaemia and 3-methylcrotonylglycinuria.

Urinary amino acids have been determined in six patients with propionic acidaemia, one of whom also showed 3-methylcrotonylglycinuria. Two patients, including the subject with 3-methylcrotonylglycinuria, showed a gross aminoaciduria with features of both cystinuria and iminoglycinuria. We suggest a defect in certain amino acid transport systems in some patients with these disorders.

Amino Acid Metabolism, Inborn Errors↗