1. To investigate the growth performance and histological intestinal alterations of Aigamo ducks fed on dietary combinations of zeolite, plant extract and vermiculite (ZEM, 14-d-old Aigamo ducks were divided into 4 groups, with 3 replicates of 3 male and 3 female ducks. They were fed ad libitum on a basal commercial duck mash diet with 0, 0.1, 0.5 and 1.0 g/kg dietary ZEM for 63 d. 2. Body weight gain tended to be higher for the 0.1 and 0.5 g/kg ZEM groups than for the control group at 9 weeks. 3. In light microscopic observation, most values of the intestinal villus height, villus area, cell area and cell mitosis numbers were higher in the ZEM group than those of the control in all intestinal segments, and the duodenal villus height, cell area and cell mitosis of the 0.5 g/kg ZEM group, as well as jejunal cell mitosis in the 0.1 g/kg ZEM group, increased (P < 0.05). In the scanning electron microscope results, all ZEM groups showed protuberant epithelial cells and cell clusters on the villus apical surface of the duodenum and ileum. In the jejunum, villus gyri were frequently observed in the 0.1 g/kg ZEM group. These histological intestinal alterations suggest that intestinal villi and epithelial cellular functions might have been activated. 4. From the present results, dietary ZEM showed hypertrophied functions of intestinal villi and epithelial cells at the duodenum and ileum, and the 0.1 and 0.5 g/kg levels improved body weight gain. These suggest that the ZEM can be supplemented until a level of 1.0 g/kg.

A glycosaminoglycan with scleroderma-inducing effect was isolated and partially purified from the urine of patients with systemic scleroderma. The glycosaminoglycan was an N-sulfated glycosaminoglycuronan and its high total sulfate and 2,5-anhydromannose contents suggest that the glycosaminoglycan is a degradation product of heparin or polysulfated heparan sulfate. Furthermore, the composition of the above glycosaminoglycan was similar to that of the N-sulfated glycosaminoglycan which we observed previously in uninvolved skin of scleroderma.

Skin proteoglycan was demonstrated by an immunofluorescent technique using an antibody against bovine cartilage proteoglycan, after the cross-reactivity of human proteoglycan with the antiserum had been confirmed. Normal skin exhibited specific fluorescence mainly in the blood vessels as well as in the subepidermal area. The clinically uninvolved skin of systemic sclerosis (SS) revealed no features different from those of normal skin. However, the vascular proteoglycan deposition of early systemic sclerosis was later replaced by deposition between the collagen fibres, which appeared to progress centrifugally in parallel to the increase in the skin sclerosis, suggesting a vascular initiation of the skin lesion. Sclerotic skin was characterized by random deposition between the collagen fibres. Immunoelectron microscopic studies suggested that the random proteoglycan deposition reflected uncontrolled local accumulation of proteoglycan in the interfibrillar matrix around irregularly arranged collagen fibrils.

The presence of sclerosis-inducing glycosaminoglycan in the skin was confirmed in an experimental skin sclerosis induced by a chemical compound. An experimental skin sclerosis was first produced in the mouse with bis(4-amino-3-methylcyclohexyl)methane. Out of glycosaminoglycans isolated from the slightly changed skin of this experimental skin sclerosis, the one having a heparan sulfate-like structure was able to again induce sclerotic skin changes in another mouse. The chemical composition of this sclerosis-inducing glycosaminoglycan was somewhat similar to that of the scleroderma-inducing glycosaminoglycan isolated previously from the urine of patients with systemic scleroderma.

Radioimmunoassay with an antibody produced against urinary low-sulfated heparan-sulfate-related protein was devised and used to screen the heparan sulfate level in the urine of patients with systemic scleroderma. Patients with diffuse scleroderma, and patients also showing polymyositis/dermatomyositis had elevated values, whereas the value in patients with acrosclerotic scleroderma did not differ from that of the control population. In addition, an increase in this protein was associated with the positivity of anti-Scl-70 antibody. These findings suggest an important role for low-sulfated heparan sulfate in the pathobiology of severe systemic scleroderma.