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Biomedical subjects

G Asboe-Hansen

Publications and source records attributed to G Asboe-Hansen.

30 records · Page 2Linked to original sources

Ultrastructure of dermal connective tissue in fibrodysplasia ossificians progressiva.

The ultrastructure of dermal connective tissue in two patients suffering from fibrodysplasia ossificans progressiva (syn myositis o.p.) was studied. The disorder starts with soft tissue swelling which subsequently ossify. The connective tissue of various organs may be affected. No defects in calcium metabolism have been discovered. It was intended to study the primary event which initiates the ossification. The present ultrastructural study demonstrates an accumulation of proteoglycan microfibrils as well as glycoprotein material in dermal connective tissue. Both substances are prerequisites of calcification resulting from the binding of calcium and phosphorus ions. A subsequent release of proteolytic enzymes in the tissues may be set free the bound iones and, thus, initiate mineralization.

Calcium

Micromethod for fractionation of acid mucopolysaccharides.

A new micromethod for fractionation of acid mucopolysaccharides based upon the use of different concentrations of HC1 to separate the complex of CPC with non-sulphated, monosulphated and polysulphated acid mucopolysaccharides (glycosaminoglycans) is presented. The method utilizes the different binding of the anionic macromolecules to the cationic compound cetyl pyridinium chloride. The method is simple and reproducible. The use of HC1 as eluent allows the exclusion of some steps required when salts are used for elution. Hexuronic acids are determined on the eluents.

Chondroitinases and Chondroitin Lyases

Simplified method for determination of protocollagen proline hydroxylase.

Preparation of (14C) Pro labeled protocollagen and requirements for its hydroxylation by PPH was investigated. Protocollagen can be prepared by centrifugation of the biological material at 15.000 X g. Substances in current use, viz catalase, bovine serum albumin and dithiothreitol were found unnecessary under the hydroxylation conditions used. A decrease in PPH in the testis and skin of rats with increasing age was demonstrated.

Animals

An assay for total hexosamine and a differential assay for glucosamine and galactosamine.

Two new procedures are presented for quantitative determination of glucosamine and galactosamine. One, which is proposed for total hexosamine, yields chromogens of equal intensity with equal concentration of glucosamine and galactosamine. There is addition of the correspondent chromogens when they are present in mixtures. The procedure is presented as a manual as well as an automated assay. The other procedure is a differential assay which allows the detection of galactosamine without interference by glucosamine. By the two procedures, the hexosamines present in acid mucopolysaccharides and/or glycoproteins can be determined.

Acetylgalactosamine

Lysolecithin fusion of cells from multiple sclerosis patients with Vero cells.

Investigations were performed on cell cultures derived from patients with multiple sclerosis (MS) in order to trace a possible virus infection as a cause of the disease. Cell cultures were established from one brain autopsy specimen and four lymph node biopsies from MS patients. Lymphocytes from 28 MS patients and six healthy controls were used for fusion or cocultivation experiments, either immediately after isolation or after mixed lymphocyte cultures (MLC). Lysolecithin fusion and cocultivation experiments were made with Vero cells and with, respectively: cultured brain cells, lymph node cells and lymphocytes from MS patients. Electron microscopical examination revealed intranuclear filamentous structures in 5 per cent of the cells in primary cultures of MS brain and lymph node and in control skin organ cultures. Multinucleated cells were found in six out of 19 cocultures of Vero cells and MS lymphocytes preincubated for 2 days at 37 degrees C. The cultures were tested for the presence of viruses, i.e. measles virus and virus producing hemadsorption with human type O and/or guinea pig erythrocytes and virus against which the MS patients showed serum FA-antibodies. No virus antigen could be demonstrated in the cells.

Adult

Influence of corticosteroids on connective tissue.

All glucocorticosteroids inhibit growth, regeneration and repair of cellular or intercellular components of dermal connective tissues, when penetrated through the skin barrier. The resulting atrophy is a logical manifestation of the action of these compounds.

Administration, Topical

Cortisol effect on collagen biosynthesis in embryonic explants and in vitro hydroxylation of protocollagen.

The effect of increasing doses of hydrocortisone acetate, hydrocortisone phosphoric acid complex, and hydrocortisone sodium succinate on collagen biosynthesis was assayed in two different systems. I. Explants of chicken embryo tibiae showed decreased biosynthesis of [14C]hydroxyproline and total and glycosylated [14C]hydroxylysine under the influence of high doses of hydrocortisone. With the lower doses of hydrocortisone acetate, no effect was noticed. The total uptake of the precursor amino acids followed patterns similar to those of collagen biosynthesis. II. Hydroxylation of [14C]proline labelled protocollagen by protocollagen proline hydroxylase was inhibited by high doses of hydrocortisone acetate, hydrocortisone phosphoric acid complex, and hydrocortisone sodium succinate. III. A decreased diffusion of collagen to the medium with increasing doses of hydrocortisone acetate, hydrocortisone phosphoric acid, and hydrocortisone sodium succinate was noticed. IV. No further hydroxylation of new-synthesized collagen was obtained under the influence of hydrocortisone phosphoric acid and hydrocortisone sodium succinate, when the undialyzable material was used as a substrate for protocollagen proline hydroxylase.

Animals

Parallel studies on collagen hydroxyproline and hydroxylysine in human skin biopsies.

Studies on hydroxyproline and hydroxylysine, the two amino acids characteristic of collagen and related glycoproteins, were undertaken on biopsies of pathologic and clinically normal human skin. No statistically significant differences between clinically normal skin of mamma, thorax, axilla, femur, hip and sacral area were found. A decreased collagen content was seen in chronic pemphigus (bullous pemphigoid), amyloidosis, scleromyxedema and the edge of a leg ulcer. Determination of both amino acids is considered necessary to characterize alterations of collagen.

Adult

Ultrastructure of localized myxedema.

Five biopsies from three patients with localized myxedema were studied by electron microscopy. The dermis showed an overwhelming accumulation of microfibrils with knobs (acid glycosaminoglycans) and an amorphous material containing glycoprotein. Furthermore, evidence of degradation without new formation of collagen fibrils was found. Considerable numbers of mast cells with various types of granules, fibroblasts with dilated granular endoplasmic reticulum, and macrophages were seen in the mucinous areas.

Adult

A selective stain for mast cells.

A selective stain for mast cells in tissue sections is presented. The procedure is based on the resistance to destaining with absolute ethanol-acetic acid of the complex acid mucopolysaccharide-Toluidine Blue reinforced with ferrioxamine B.

Acetates

Treatment of generalized scleroderma with inhibitors of connective tissue formation.

103 patients suffering from generalized scleroderma were studied in order to assess the effect of treatment with inhibitors of connective tissue formation. 93 patients with generalized scleroderma were given D-penicillamine, benzyl-penicillin-diethylamino-ethyl-ester hydroiodide, adrenal glucocorticoids, dextro-thyroxine, hydralazine, and "mixed treatment" (one or several of the drugs in consecutive courses, or concurrently). The effect of dextrothyroxine could not be evaluated in this study. No improvement could be seen after adrenocortical steroid therapy. Hydralazine seemed to be effective. D-penicillamine improved 25 of 34 treated patients; penicillin hydroiodide 12 out of 16. The dermal sclerosis of 6 patients regressed completely; in 16, sclerosis regressed with the exception of finger sclerosis; in 32, partial regression was registered; 20 had their progression arrested, but there was no regression; in 19 cases, there was no effect whatsoever. The prognosis seemed to be better for young than for old people. The age at onset was lower in the better groups. The higher the total dose, the better the results. The length of the treatment course is probably of some significance. The short-lasting cases had better prospects than the longer lasting. Ten untreated patients of this material and 11 patients seen earlier showed continued progression. Side effects leading to discontinuation of the drugs were seen in a substantial number of patients, especially after D-penicillamine. Twelve deaths could not be related to the treatments.

Adult