Different immunological mechanisms contribute to cartilage destruction in antigen-induced arthritis.

Antigen-induced arthritis in guinea pigs was used as a model to investigate the pathogenic mechanisms responsible for cartilage destruction in chronic joint inflammation. The activation of macrophages, their effects on cartilage metabolism, and the development of autoimmunity to cartilage constituents were studied during the progression of arthritis. The results show that in arthritic animals the macrophages are systemically activated, with a peak in the early phase of inflammation.

The glycosaminoglycans in cultures of stimulated rat peritoneal macrophages. 2. Gel chromatographic studies and the behaviour of heparan sulfate.

The molecular weight distribution of pMP-derived glycosaminoglycans (GAG), i.e. non-sulfated GAG, chondroitin sulfate (CS), and heparin sulfate (HS)-like material was determined.

The glycosaminoglycans in cultures of stimulated rat peritoneal macrophages. 1. Pattern and biosynthesis of glycosaminoglycans.

Macrophages produce and secrete proteoglycans. They are involved in inflammation and may contribute to the glycosaminoglycans (GAG) and proteoglycans (PG) characteristic of the inflamed area. This possible contribution was studied with rat peritoneal macrophages (pMP) in vitro.

Bacillus Calmette-Guérin (BCG) influences cell proliferation and glycosaminoglycans of chondrocyte cultures.

There are only few reports on the correlation between bacterial products and the GAG pattern of cartilage. Mycobacteria bovis (BCG) were applied to chondrocyte monolayer cultures for one week. The following parameters did change: cell proliferation increased, glycosaminoglycan synthesis and secretion decreased, hyaluronic acid in secreted and cell-associated glycosaminoglycans increased, a correlation between the degree of these changes and the degree of cell differentiation seems to exist.

The glycosaminoglycan metabolism of chondrocyte monolayer cultures under normal and pathological conditions. A methodic study.

Chondrocyte cultures may serve as a model in investigating changes of the cartilage metabolism. Adherent chondrocytes in vitro maintain polygonal morphology at high cell density in the primary and secondary culture. Collagen type II is only clearly detected in multilayered or nodular areas.

Chondrocytes may activate macrophages.

It is demonstrated that conditioned media of articular chondrocytes cultured with Bacilli Calmette-Guérin are capable of activating macrophages. This activation reaches different levels and is expressed both by different cell survival and enhanced synthesis of glycosaminoglycans that remain cell-associated (exp. group III) or are secreted (exp.

Effect of the microbial constituents, LPS and BCG, on the glycosaminoglycans of chondrocyte cultures.

Earlier we reported that articular chondrocytes in monolayer culture produce pericellular proteoglycans both with short and long half lives, T-1 and T-2 (Kittlick et al. 1991 b). Now monolayer cultures have been investigated to assess the influence on the metabolism of pericellular proteoglycans or glycosaminoglycans by lipopolysaccharide of E.

The glycosaminoglycans of the macrophage-like cell line PeMa in suspension and monolayer culture.

The macrophage-like cell line PeMa was cultured both in suspension and in monolayer for biochemical studies. It is concluded that adherent PeMa when compared with suspended cells --contain three times more GAG in medium, cell coat, and cells: --contain higher amounts of HS and CS in the cell coat; --release a minor proportion of sulfated GAG (HS) into the medium; --contain in their medium longer chains of HS and CS/DS; --contain in cell coat and cells higher amounts of a family of HS chains with high to low molecular weights. In suspension and monolayer cultures, the cell coat GAG were scarcely labelled; they are likely to be produced at another time and to turn over slowly.

Redox status of cultured fibroblasts. Possible relations with specific catabolic rates of proteoglycans.

Unlabelled: In cultured embyonic rat fibroblast the cytoplasmic NAD/NADH ratio was determined from the lactate/pyruvate ratio under acidic, hypoxic and lactic acid-rich conditions.

Results And Conclusions: The NAD/NADH ratio is reduced when the lactate concentration increases at pH 7.4 with and without hypoxia.

Modification of fibroblastic glycosaminoglycan pattern by soluble factors obtained from sensitized lymphocytes.

Lymph node cells were obtained from BCG-sensitized guinea pigs and cultured without (C) and with (Ag) PPD challenge. The dialyzed lymphocyte (LC) supernatants were added to the medium of monolayer cultures of embryonic rat fibroblasts. They were assayed at different cell densities and in the presence and absence of serum.

Effect of thrombin on glycosaminoglycans in fibroblast cultures.

Embryonic rat fibroblasts were incubated with thrombin of different concentrations for 48 hrs. in the absence of calf serum. Cell proliferation was increased in dense cultures only.

Synovial membrane in rheumatoid arthritis: determination of glycosaminoglycans and age-dependent correlations.

From 16 synovial membranes patients with rheumatoid arthritis morphological parameters as well as the GAG distribution pattern have been determined using 2 methods each. The results were checked by discriminant and regression analysis: The total GAG concentration of the synovialis was significantly correlated with the sum of the parameters "fibrin in organization", "granulocytes" "nad "necroses" (acute activity). A highly significant correlation between the age of patients and the severity of chronic morphological alterations (basic activity, especially proliferation) was found.

Fibrin in fibroblast cultures--a metabolic study as a contribution to inflammation and tissue repair.

Embryonic rat fibroblasts were cultured in the presence of fibrin under fibrinolytic and fibrinostatic conditions both in proliferating and confluent stages. The proliferation rate, glucose consumption, glycosaminoglycan contents and distribution pattern were determined. Additionally the influence on rat fibroblast cultures of fibrinogen and its splitting products were reinvestigated.

Clotting factors added to fibroblast cultures. Their action on glycosaminoglycans and other parameters.

To monolayer cultures of embryonic rat fibroblasts in the proliferative and stationary phase of growth there were given: thrombin, fibrinogen or fibrin supernatant, respectively. Their effects on cell proliferation, glucose consumption and glycosaminoglycans were recorded and observed to be more pronounced in serum-depleted and confluent cultures. Thrombin in serum-supplemented cultures was nearly ineffective.

The action of a single toxic dose of 2-acetylaminofluorene or allylic alcohol on the adrenals. II. Effect on adrenal cyclic 3',5'-adenosine monophosphate concentration during the 1st and 2nd day.

In the adrenals of male Sprague-Dawley rats the concentration of cyclic 3',5'-adenosine monophosphate (cAMP) was studied 5, 10, 14, 24, 30 and 39 hours after single intoxication by 2-acetylaminofluorene (AAF) or allylic alcohol (ALL). Beside diurnal changes a transient elevation of adrenal cAMP concentration occurred when compared with the controls 10 hours after intoxication. Thereafter, up to the 30th hour of investigation the values of the experimental groups as well as those of the control groups were within the same range.

Acid mucopolysaccharides in fibroblast cultures. 4. 35S-sulfate incorporation in dependence on pH-value cell density and lactate.

Unlabelled: Cultures of embryonic rat fibroblasts were incubated with 35S-sulfate at pH 6.6 and 7.4 (Eagle medium, Hepes buffer) for 48 hours.

Hypoxia in fibroblast cultures. 4. Cell density, glucose utilization and acid mucopolysaccharides in 1% O2 concentration.

Secondary cultures of embryonic rat fibroblasts incubated in Eagle medium with Hepes buffer at pH 6.6 and 7.4 were maintained in hypoxia of 1% O2 for 48 hours.

Hypoxia in fibroblast cultures. 3. 35S-sulfate incorporation into acid mucopolysaccharides as influenced by 5% O2 hypoxia with simultaneous changes in the lactate-and H-ion concentrations.

The influence of 5% O2 hypoxia on the 35S-sulfate incorporation into different mucopolysaccharide fractions was studied in monolayer cultures of embryonic rat fibroblasts before reaching the stationary phase. Besides the O2 concentration also the pH value and lactate concentration were varied in the experiments. The results are valid for proliferating cell cultures.

[The synovial membrane in rheumatoid arthritis: change in the glycosaminoglycan pattern].

For examination of glycosaminoglycane (GAG) in the normal synovial membrane and in the synovial membrane of patients with rheumatoid arthritis (RA) fat free dry tissue was digested with papain. The GAG was fractonated with cetylpyridiniumchloride according to Svejcar's and Robertson's techniques and afterwards it was characterised in detail. The total amount of GAG per gramme of fat free dry tissue was the same in RA and in controls.

Acid mucopolysaccharides in fibroblast cultures. 2. 35S-sulfate incorporation kinetics in dependence on pH-value and cell density.

Cultures of embryonic rat fibroblasts were incubated with 35S-sulfate at pH 6.6 and 7.4 (Eagle basal medium plus HEPES buffer) for 12 to 48 hours.

Acid mucopolysaccharides in fibroblast cultures. 1. Influence of cell density, pH-value and lactate concentration on the MPS distribution pattern.

From cells and culture media of embryonic rat fibroblasts (1st subculture) the acid mucopolysaccharides were isolated and fractionated. The per cent calculation of the 6 fractions was based on the content of glucuronic acid. The cultures were maintained as follows: 0.

Studies on cartilage formation. XVIII. Changes of the composition of glycosaminoglycans in the regenerating articular surface.

The cartilaginous articular surface of the distal part of the femur of adult dogs was removed and the composition of GAGs was determined in the granulation tissue adhering to the bone wound and in that adhering to the articular capsule 7, 33, and 70 days after operation. The articular cartilage and the synovial layer of the articular capsule of intact adult dogs were also studies. The materials were digested with papain and the released GAGs were fractionated according to Svejcar and Robertson's method.