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Biomedical subjects

U Langness

Publications and source records attributed to U Langness.

At least 19 recordsLinked to original sources

[Analysis of the hydroxyproline containing serum proteins in connective tissue diseases (author's transl)].

The serum proteins were fractionated on Sephadex G 200, their hydroxyproline content determined. Three protein peaks (I-III) containing different hydroxyproline concentrations could be separated. In connective tissue disorders accompanied by increased collagen synthesis or collagen degradation, an elevation of hydroxyproline was found in peak II. An increase of hydroxyproline always was associated with an increase of the serum proteins in the same fractions. Hydroxyproline serum levels above normal obviously are due to a certain capacity of the serum proteins binding free hydroxyproline and collagen metabolites.

Blood Proteins

[Prolyl hydroxylase activity in liver specimens in chronic liver diseases (author's transl)].

100 patients were laparoscopied, liver tissue specimens taken from atypically altered areas. Prolyl hydroxylase was determined in the specimen, in parallel tissue was examined by light microscope. 8 groups of patients could be differentiated: Patients 1. with active, 2, with inactive cirrhosis, 3. with fatty infiltrations, 4. with fatty infiltration and mesenchymal reaction, 5. with aggressive, 6. with persistent, 7. with reactive hepatitis, 8. patients without histological changes. In the case of connective tissue increase in the liver prolyl hydroxylase activities were statistically significant above normal. In addition, there was a statistically significant difference between the enzyme activities of each group. A correlation could be found between prolyl hydroxylase activity and morphologically estimated connective tissue formation, but not the serum enzyme activities usually determined in liver diseases. Therefore, could be concluded that prolyl hydroxylase activity is an index of actual collagen biosynthesis in chronic liver diseases.

Adult

[Parameters of collagen biosynthesis in cotton pellet granuloma of rats on iron deficiency (author's transl)].

Rats of Wistar strain, of same age, were kept on iron free diet up to nearly absolute iron deficiency in iron depots. Afterwards granuloma was produced by implantation of cotton pellets subcutaneously. For characterization of the collagen biosynthesis in the granuloma the neutral salt soluble collagen and the activity of the prolyl hydroxylase were measured in the granuloma 4, 8 and 12 days after cotton pellet implantation. At the same time "collagen-like" protein was determined in the serum of the animals. The enzyme activity was statistically significant lower in the granuloma of animals on iron deficiency than in the granuloma of the comparable groups on normal diet. Statistically significant higher concentration of neutral salt soluble collagen was found 8 and 12 days after cotton pellet implantation in the group on iron free diet. There was no significant difference as to the serum levels of "collagen-like" protein in serum.

Anemia, Hypochromic

[Proliferation of L 929 mouse fibroblasts and synthesis of active peptidyl prolyl hydroxylase in these cells in monolayer culture under the influence of D-penicillamine, azathioprine, aurothiopolypeptide, oxyphenbutazone and prednisolone (author's transl)].

L 929 mouse fibroblasts were cultured as monolayer using MEM Eagle medium after addition of bovine serum albumin, antibiotics, antimycotica, ferrous nitrate and ascorbic acid. In 24 hours distances cell number was counted. At the same time peptidyl prolyl hydroxylase activity was determined and related to the protein concentration in the cells. The proliferation of the cells followed a typical curve. The cell number decreased after trypsination, then increased logarithmically, finally reached a stationary phase. Enzyme activity showed a correspondent curve. Active enzyme did not appear until near the end of the log phase. After addition of the mesenchyme active substances in therapeutical concentrations proliferation and synthesis of active peptidyl prolyl hydroxylase in the cells were significantly decreased. The results are discussed in relation to the characteristics of collagen synthesis and proliferation of connective tissue cells under physiological, pathophysiological and therapeutical conditions.

Animals

[Proliferation of L 929 mouse fibroblasts and their glycosaminoglycan synthesis in monolayer cultures after addition of penicillamine, azathioprine, gold thiopolypeptide, oxyphenbutazone and prednisolone (author's transl)].

L 929 mouse fibroblasts were cultured as monolayers. Proliferation and glycosaminoglycan content in cells and medium were measured, the different glycosaminoglycans fractionated. It was shown that logarithmic cell growth is followed by a stationary phase. Glycosaminoglycan synthesis started later than did cell growth and continued during stationary phase. The glycosaminoglycan pattern changed with the phase of proliferation. All mesenchyma-active substances reduced proliferation and glycosaminoglycan synthesis significantly when added in therapeutical concentrations. The fractionation of the glycosaminoglycans after addition of the exclusively suppressive substances revealed different effectivity on the different components. All substances were directly effective on the connective tissue forming cells as had been expected from clinical experience and former experiments.

Animals

[Biochemical methods in the assessment of activity in rheumatoid arthritis (author's transl)].

An investigation was carried out in 120 patients with classical rheumatoid arthritis (RA). Prolylhydroxylase activity was determined in the synovial membrane and serum and compared with the level of collagen-like protein in plasma and the hydroxyproline-creatinine quotient in urine. The data were related to the activity of RA as measured according to Voit and Gamp and also according to Lansbury. Activity was, furthermore, also assessed on the basis of newly defined criteria considering clinical, biochemical and histological findings. Prolylhydroxylase activity was significantly correlated to the activity of the RA assessed according to each of these systems. The significance of the known parameters, collagen-like protein in plasma and hydroxyproline-creatinine quotient in urine were confirmed in this larger series of patients. The positive correlation between prolylhydroxylase activities in the synovial membrane, as well as in serum, and the level of collagen metabolites in plasma and urine corroborated the value of biochemical methods in the assessment of activity of RA in order to undertake differentiated therapy.

Arthritis, Rheumatoid

[Peptidyl prolyl hydroxylase activity in relation to the actual collagen biosynthesis in cotton pellet granuloma of guinea pig (author's transl)].

During the different stages of granuloma formation peptidyl prolyl hydroxylase activity and neutral salt soluble collagen were determined in the granuloma tissue. In parallel peptidyl prolyl hydroxylase activity, "collagen-like protein", and free hydroxyproline were measured in the serum of the same animals at correspondant time distances. A close correlation was found between the enzyme activity and the other parameters of collagen synthesis. These results confirm the conclusion that hydroxylation of polypeptide may be a rate limiting step in collagen biosynthesis. In addition the investigations revealed a close correlation between enzyme activity in the tissue and enzyme activity in the serum.

Animals

Collagen biosynthesis in nonfibroblastic cell lines.

Prolyl hydroxylase and other enzymes of collagen synthesis have been found in cloned cells, including epithelium, melanoma, liver, HeLa, pituitary, kidney, and neuroblastoma. The significance of collagen biosynthesis in nonfibroblastic cells lines is discussed.

Animals