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Biomedical subjects

J Kofoed

Publications and source records attributed to J Kofoed.

10 recordsLinked to original sources

Study of the Hurler syndrome using cell culture: definition of the biochemical phenotype and the effects of ascorbic acid on the mutant cell.

Fibroblasts from patients with Hurler syndrome retain a distinctive biochemical phenotype when grown in culture which is characterized by increased synthesis of both nonsulfated and sulfated glycosaminoglycans. Ascorbic acid reinforces the phenotypic expression of the biochemical abnormality, producing not only increased synthesis of sulfated glycosaminoglycans, but selective retention of sulfated glycosaminoglycans within the cell. Although the synthesis of nonsulfated glycosaminoglycans is also increased, these compounds, particularly hyaluronic acid are not retained by the cell but are secreted into the medium. Analyses of urine from patients with Hurler syndrome show increased absolute concentrations of nonsulfated glycosaminoglycans in addition to the expected increase in sulfated glycosaminoglycans. This indicates that the biochemical phenotype as defined in cell culture is not an artifact of the experimental model but reflects the biochemical defect in the patient. Redefinition of the biochemical defect to include nonsulfated as well as sulfated glycosaminoglycans contradicts explanations of this disease which are based on a single structural gene mutation.

Ascorbic Acid↗

Vitamin C-induced increase of dermatan sulfate in cultured Hurler's fibroblasts.

In fibroblasts taken from patients witli Hurler's syndromne and grown in cultlure, dermatan sulfate constituted a larger percentage of the total sulfated glycosaminoglycans than it did in cultured fibroblasts from unaffected individuals. Moreover, the addition of ascorbic acid (vitamnin C) to the culture medium markedly increased the concentration of dermatan sulfate in the Hurler's fibroblasts but not in the normal fibroblasts. The biochemical phenotype of the Hurler's cells persisted during 28 weeks of serial culture.

Ascorbic Acid↗

Toxicological statistics for barbiturates, other sedatives, and tranquillizers in Ontario: a 10-year survey.

A steady increase in the number of cases of poisoning due to barbiturates, tranquillizers and non-barbiturate sedatives has been noted for Ontario by the Attorney-General's Laboratory, Toronto, during the period 1955-1964 on the basis of submitted material. Five cases of poisoning by barbiturates were recorded in 1955 and 193 in 1964.Urine and blood samples from persons charged with driving motor vehicles while under the influence of drugs were also examined. In 1958 only one such case was reported to the Laboratory, whereas 25 cases were recorded in 1964; barbiturates were detected in 18 of these 25. Patients must be warned of the risks of ingesting alcohol while receiving barbiturate treatment.

Automobile Driving↗

Proteoglycans in bones of streptozotocin-induced diabetic rats.

Insulin seems to regulate the biosynthesis of proteoglycans in some tissues such as growth plate and glomeruli. The present investigation was undertaken to assess the ex vivo influence of insulin on proteoglycan metabolism in bones. Mandible and femur bones were used. Xiphoid cartilage was used as a control tissue of high glycosaminoglycan content. Diabetes was induced by 0.12 mg/g b.w. streptozotocin in male Sprague-Dawley rats, a number of which was treated with insulin (1 I.U./100 g b.w.) for 6 days. As compared with control animals, diabetic rats exhibited a decreased [35S]sulfate uptake as well as a shift to the right in Sephacryl S-500 chromatography. In addition, they showed lower density of proteoglycans in sucrose gradient and shorter glycosaminoglycan side chains in Sephadex G-200 chromatography. These changes were partly reversed by insulin.

Animals↗