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W Sinn

Publications and source records attributed to W Sinn.

24 records · Page 2Linked to original sources
PubMed1980

Regulation of heparan sulphate metabolism by adenosine 3':5'-cyclic monophosphate in hepatocytes in culture.

Freshly isolated rat hepatocytes maintained as monolayers in a serum-free medium synthesize sulphated glycosaminoglycans, most of which behave as heparan sulphate and are mainly distributed into intracellular compartments. Cyclic AMP, dibutyryl cyclic AMP, glucagon, noradrenaline, prostaglandin E(1), and theophylline, all drugs and hormones known to increase intracellular cyclic AMP concentrations, decreased the incorporation of (35)SO(4) (2-) into heparan sulphate of intra-, extra- and peri-cellular pools. The inhibition mediated by dibutyryl cyclic AMP was dose-dependent and observed as early as 2h after exposure to the drug. In the presence of 1mm-dibutyryl cyclic AMP, incorporation of (35)SO(4) (2-) or [(14)C]glucosamine into heparan sulphate was decreased to 40-50%, suggesting that dibutyryl cyclic AMP interfered with the synthesis of heparan sulphate. This was further supported by pulse-chase experiments, where dibutyryl cyclic AMP had no effect on the degradation of sulphated glycosaminoglycans. Heparan sulphates synthesized and secreted into the extracellular pool in the presence of dibutyryl cyclic AMP were smaller in size, whereas the degree of sulphation and molecular size of the heparan sulphate chains released by beta-elimination from these proteoglycans were not different from control values. In the presence of 1mm-cycloheximide, (35)SO(4) (2-) incorporation was decreased to 5%. Addition of p-nitrophenyl beta-d-xyloside, an artificial acceptor of glycosaminoglycan chain synthesis, enhanced this incorporation to 18%. Dibutyryl cyclic AMP did not have any inhibitory effect on the synthesis of chains initiated on p-nitrophenyl beta-d-xylosides. Incorporation of [(3)H]serine into heparan sulphate was not affected by dibutyryl cyclic AMP, whereas the degree of substitution of serine residues with heparan sulphate chains was less in heparan sulphate synthesized in the presence of dibutyryl cyclic AMP, suggesting that cyclic AMP exerts its effect on the metabolism of sulphated glycosaminoglycans by affecting the transfer of xylose on to the protein core.

Animals↗
PubMed1980

[Glomerulonephritis therapy. Immunosuppression or coagulation inhibitors - a comparison].

In 110 patients with mesangioproliferative glomerulonephritis the treatment (n = 48) with chlorambucil, warfarin, dipyridamol and prednisone (CAA) and the treatment with imuran and prednisone (CP, n = 23) are compared with the conditions of an untreated control group. The CAA-therapy is above all suited for active clinical pictures without sclerosis with short duration of the disease, even when the renal function is already restricted. The CP-therapy is suitable in non-active forms with sclerosis also in a longer duration of the disease.

Anticoagulants↗
PubMed1980

Metabolism of sulfated glycosaminoglycans in rat hepatocytes. Synthesis of heparan sulfate and distribution into cellular and extracellular pools.

Primary cultures of rat hepatocytes grown in a serum-free medium supplemented with [35S]sulfate synthesize 35S-labelled glycosaminoglycans at an almost constant rate for 58 h. Approx. 57% of the newly synthesized 35S-labelled glycosaminoglycans remain within the hepatocytes, approx. 30% become associated with the cell surface and only 13% are secreted into the medium. The amount of cell-surface-associated 35S-labelled glycosaminoglycans became constant within 36 h, whereas no equilibrium was reached in the intra- and extracellular pool. During a 24 h chase more than 50% of the intracellular and cell-surface-associated 35S-labelled glycosaminoglycans disappears, more than 80% of this material is degraded and radioactivity is recovered as inorganic sulfate. A minor part is released into the medium in a macromolecular form. Heparan sulfate accounts for more than 95% of the 35S-labelled glycosaminoglycans in each of the three pools. It is distinguished from heparan sulfates from other sources by the presence of unsubstituted glucosamine residues. In all three pools, heparan sulfate chains of mean molecular weights between 24 000 and 30 000 are part of an alkali labile proteoglycan. Intra- and extracellularly, however, part of the heparan sulfate appears to have little, if any, protein attached. Hepatocytes contain heparan sulfate-degrading endoglycosidase activity, which may contribute to the variation of molecular weights observed for the heparan sulfate.

Animals↗
PubMedDate not supplied

[Treatment of hip joint dislocation with the Hanausek apparatus].

The Hanausek apparatus has been used for reposition and retention of luxation of the hip joint in the Orthopädische Klinik Hessisch Lichtenau in 37 cases aged up to 2 years, if there was no hindrance of reposition in arthrography. It is a functional method which avoids the extreme Lorenz position that is claimed to endanger the caput femoris respecting necrosis. In a retrospective roentgenological observation it became evident, that the method of Hanausek leads generally to a good development of the acetabulum. The rate of necrosis in our patients was high (17%). Our patients started treatment later (38% aged more than one year). 2/3 of the patients had a high luxation of the hip joint.

Acetabulum↗