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Two hepatotrophic protein factors (HTF) were partially purified from the serum-free conditioned medium of the embryo rat fibroblastic cell line FRL. HTF induced cell adherence to the culture plate, promoted life maintenance, scattering and enhanced 3H-Thymidine uptake into DNA and cell proliferation in two sensitive murine non-transformed, epithelial hepatocytic cell lines (C6 and C2.8). In this bio-assay, cells were plated at low density in Dulbecco's Modified Eagle's Medium, in the absence of serum and other exogenous growth factors. HTF did not synergize with epidermal growth factor. Biological activity was associated to two major acidic proteins: a non-heparin-binding protein (M(r) approximately 70 kDa, pI 4.6-4.5) and a heparin-binding protein (M(r) approximately 200 KDa, pI 4.3-4.1).

1. Two soluble proteins, with good affinity to tritiated 2-isobutyl-3-methoxypyrazine, have been purified from mouse nasal mucosa. 2. The first protein is a heterodimer with subunits of apparent M(r) 18 and 19 kDa and isoelectric point of 4.9; the second is a monomer of M(r) 21 kDa and isoelectric point of 4.8. 3. The characteristics of these binding proteins are compared with those of the other known OBPs and urinary proteins and their putative role is discussed.

A heparin-binding protein, acting as a potent hepatocyte growth stimulating factor (HGSF) was extracted and partially purified from normal calf serum. HGSF stimulated DNA synthesis and proliferation in primary cultures of adult Balb/c mouse hepatocytes and in two liver-derived epithelial cell lines (C6 and C2.8) plated at low cell density in serum-free medium in the absence of epidermal growth factor. HGSF was non-dialyzable in M(r) 50,000 cutoff membranes, and was purified after chromatofocusing on PBE94 resin, (NH4)2SO4 precipitation (80% salt concentration) of the active fractions eluted at pH 5.7, flow chromatography and elution through Sephacryl S300 HR and HA-Ultrogel columns. The hepatotrophic activity was eluted with a protein fraction that was concentrated approximately 40,000 fold over the starting material. The effect was half maximal at approximately 50 ng/ml on adult hepatocytes in primary culture, HGSF had a molecular weight of 90,000-110,000 by gel filtration, was unstable on heat-treatment and was completely inhibited after trypsin digestion and after reduction with dithiothreitol. HGSF did not stimulate growth in Balb/c 3T3 fibroblasts. When injected into partially (40%) hepatectomized Balb/c mice, HGSF increased hepatic DNA synthesis 2 to 4-fold over the background stimulation, at 20 hours after the hepatectomy.

1. Soluble proteins showing binding activity to 2-isobutyl-3-methoxypyrazine have been purified to homogeneity from rabbit and pig nasal tissue; their characteristics are similar to the bovine odorant-binding protein and are to be considered members of the same family. 2. The rabbit protein is a homodimer with subunits of Mr 19k and an isoelectric point of 4.7, whereas the pig protein appears to consist of a single polypeptide chain of Mr 22k and an isoelectric point of 4.2. 3. Both proteins bind 2-isobutyl-3-methoxypyrazine with dissociation constants in the micromolar range. 4. Antibodies against the bovine OBP react well with the rabbit protein, and slightly with the porcine one.

Exercise is worth while for general health and well being; and is beneficial and safe for the young with IDDM as well. The patient must learn to adapt to insulin and/or diet, attending education and training program. The many examples of world-class athletes and participants in the Olympic Games with diabetes serve as impressive evidence that in spite of being dependent on insulin, they are able to participate successfully and without complications in physical activities and high-performance sports.