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Biomedical subjects

S O Lie

Publications and source records attributed to S O Lie.

At least 73 records · Page 4Linked to original sources
PubMed1988

Screening for cystic fibrosis among newborns in Norway by measurement of serum/plasma trypsin-like immunoreactivity. Results of a 2 1/2-year pilot project.

A pilot project for neonatal screening for cystic fibrosis (CF) by measuring trypsin-like immunoreactivity (TLI) in liquid serum or plasma samples was carried out in Norway from May 1982 to December 1984. A total of 72,320 newborns was screened. Twelve infants were recalled for sweat testing; 11 were confirmed to have CF. One infant had normal sweat sodium and chloride levels and no clinical symptoms. The incidence of CF in this study was 1:6574, and the recall rate for second blood samples was 0.6%. No false-negative cases have yet been reported. The level of TLI was affected by the use of heparin in plasma preparation, being reduced by about 20% as compared to serum levels.

Cystic Fibrosis↗
PubMed1986

Vitamin C and thiol reagents promote the in vitro growth of murine granulocyte/macrophage progenitor cells by neutralizing endogenous inhibitor(s).

Growth of murine hemopoietic cells in culture requires the presence of a stimulator of stem cell proliferation, "colony stimulating factor" (CSF). A widely used source of CSF is lung conditioned medium (LCM). We have earlier shown that the great variability of CSF activities in different batches of LCM is due to varying amounts of inhibitor(s). The present study expands the observation that the addition of ascorbic acid to the murine bone marrow soft agar assay system removes the inhibitory activity. The vitamin probably acts as an antioxidant or free radical scavenger, since addition of reduced (but not oxidized) glutathione, cysteine, dithiothreitol or 2-mercaptoethanol to the cultures also inactivates the endogeneous inhibitor. Cysteine and glutathione gave the highest colony numbers, were active at concentrations present in body fluids and did not inhibit colony growth even at concentrations ten times higher than optimum. No synergistic effects could be observed between the different antioxidants. At optimum concentration (usually 0.45 mmol/l) the otherwise bell-shaped dose-response curve for conditioned medium changed to a sigmoid curve. Antioxidants had no growth promoting effect in the absence of CSF. The presence of cysteine or vitamin C revealed CSF-like activity in conditioned media of tissues not considered to be potent producers of such factors. It has been reported that individual batches of foetal calf serum contain different levels of reduced glutathione, and we suggest that one of the batch variable growth regulators in foetal calf serum may be reduced glutathione. The results indicate a possible physiological role of antioxidants in granulopoiesis and suggest that cysteine or reduced glutathione should be freshly added to culture systems assaying CSF and/or granulocyte macrophage progenitor cells.

Animals↗
PubMed1986

C-reactive protein as an indicator of infection in the immunosuppressed child.

C-reactive protein (CRP) concentrations were determined in a prospective fashion in 50 children with malignant disease. In 35 children with active and aggressive disease, but without signs of infection, no significant increase in CRP was detected. Neither did aggressive cytostatic therapy (70 courses) in non-infected children result in an increase. In bacteriologically proven, and in clinical sepsis-suspected cases, CRP values increased in all cases to levels above 100 mg/l (normal values less than 5 mg/l). Effective antibiotic therapy resulted in a prompt decline in CRP. Viral infections resulted in a much smaller increase. We conclude that serial measurements of CRP in these immunosuppressed children are of great help in monitoring infections and defining the group that needs antibiotic therapy. The measurement is also a good indicator of the effectiveness of the antibiotic therapy chosen.

Adolescent↗
PubMed1986

Endogenous inhibitors of human granulocyte/macrophage colony forming cells in vitro are inactivated by free radical scavengers.

Granulocyte/macrophage colony forming cells (GM-CFC) require colony stimulating factors (CSF) for growth in vitro. Crude preparations of CSF also contain inhibitors. To investigate whether this inhibition involves free radicals, the following scavenging agents were tested on human GM-CFC grown in agar: cysteine, reduced glutathione, dithiothreitol, sodium selenite, alpha-tocopherol, superoxide dismutase, catalase and ascorbic acid. All except ascorbic acid and catalase had enhancing and stabilising effects on colony formation. The colonies also contained more cells but no changes in cell composition were detected. Cysteine, the most extensively tested substance, was active at concentrations present in body fluids and enhanced colony formation without an exogenous source of CSF. Our results are consistent with an imbalance between the production and removal of free radicals generated in the human GM-CFC assay in vitro. This hampers investigation of regulators of granulopoiesis and results in underestimation of GM-CFC, but can be alleviated by the addition of free radical scavengers.

Bone Marrow Cells↗
PubMed1986

Demonstration of 26-hydroxylation of C27-steroids in human skin fibroblasts, and a deficiency of this activity in cerebrotendinous xanthomatosis.

26-Hydroxylation of 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha-triol and other C27-steroids was demonstrated in cultured skin fibroblasts from healthy individuals. Activities in skin fibroblasts were approximately 5-10% of those previously found in human liver homogenates, and were inhibited by CO. The apparent Km was lowest for 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha-triol (1.3 mumol/liter) and highest for 5-cholestene-3 beta, 7 alpha-diol (12 mumol/liter). The rate of 26-hydroxylation was highest with 7 alpha-hydroxy-4-cholesten-3-one. These characteristics are similar to those of hepatic mitochondrial C27-steroid 26-hydroxylase. In skin fibroblasts from three patients with cerebrotendinous xanthomatosis (CTX), 26-hydroxylation of C27-steroids proceeded at a rate of only 0.2-2.5% of healthy controls. No accumulation of endogenous 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha-triol could be demonstrated in these cells, and the lowered formation of radioactive, 26-hydroxylated products could not be explained by dilution of the labeled exogenous substrate. The present results add strong evidence to the concept that the primary metabolic defect in CTX is a deficiency of C27-steroid 26-hydroxylase.

Brain Diseases↗
PubMed1986

Phytanic acid oxidase activity in cultured skin fibroblasts. Diagnostic usefulness and limitations.

Patients with Refsum's disease lack the ability to degrade phytanic acid to pristanic acid and CO2. This defect is expressed in fibroblasts from the patients. An assay system for the degradation of phytanic acid in cultured skin fibroblasts is described. The assay makes it possible to single out patients with Refsum's disease from the cob-web of clinically related conditions. The sensitivity is, however, not good enough to diagnose the heterozygous state. A defect of the same pronounced degree as in Refsum's disease is also found in fibroblasts from patients with Zellweger's syndrome, neonatal adrenoleukodystrophy, and infantile Refsum's disease. The radioactive material remaining in the cells after incubation was identified as unmetabolized phytanic acid. No traces of radioactive intermediates could be found in the cells from any of the patient groups. This might indicate that the defects both in Refsum's disease and in the peroxisomal disorders are located either at the same metabolic step or at steps which are closely linked to each other.

Carbon Dioxide↗