Stabilization and protection of an enzymatic system, participating in the transformation of beta-carotene into retinal, during its isolation]

The authors studied the effect of dithiothreitol (DTT), carotenoids and protease inhibitors on stabilization and protection of the enzyme catalysing the conversion of beta-carotene into retinal during the enzyme isolation from the rabbit small intestine. The addition of 1 mM DTT into the homogenization mixture increased the activity of the enzyme 5 times compared with control. The additional introduction of 0.7 mg/ml soybean trypsin inhibitor or 2.10(-4) M phenylmethylsulfonyl fluoride increased the enzyme activity 2.1 and 1.2 times, respectively. Lutein, beta-carotene and lycopene at a concentration of 10 mg/ml increased the enzyme activity 2.1, 1.9 and 1.6 times respectively. The effects of DTT, lutein and the protease inhibitor depended on their concentrations and was of an independent additive character. The maximum activity of the isolated enzyme exceeded the control without DTT 15 times.     

Immunohistochemistry of thyroid hormones as a functional parameter in thyroid pathology

The authors study by means of immunoperoxidase method the pattern of thyroglobulin, triiodothyronine and thyroxine distribution in 58 cases of thyroid disorders: 15 euthyroid goiters, 10 Graves' disease, 7 Hashimoto's thyroiditis, 11 folliculo-papillary carcinomas (6 primary tumors and 5 lymph node metastases), 8 follicular carcinomas, 4 anaplastic carcinomas and 3 medullary carcinomas. Thyroglobulin, triiodothyronine and thyroxine were present in most of the thyroid disorders, excepting anaplastic and medullary carcinomas. Thyroglobulin and thyroxine were localized both in the follicular epithelium and in the colloid, whereas triiodothyronine was present especially in the follicular cells. The thyroid hormones distribution in benign lesions is rather similar. In carcinomas, the pattern of thyroglobulin, triiodothyronine and thyroxine is more heterogeneous, but generally the triiodothyronine distribution is similar to that of thyroglobulin. In some carcinomas, triiodothyronine and thyroxine showed a weak or negative immunostaining. The immunoperoxidase method is a valuable tool in the study of functional disturbances in the thyroid pathology and in the diagnosis of thyroid carcinoma metastases as well. Positive thyroid hormones staining clearly indicates the thyroid origin of metastases.     

High molecular substances in relation to disorders of erythropoiesis in patients in the terminal stage of chronic renal failure

Fraction F1 with a MW of 5.10(3)-5.10(4), which had been isolated from the blood serum of blood donors as controls and patients at the terminal stage of chronic kidney insufficiency, specifically inhibited the erythropoiesis of test animals at the stage sensitive to erythropoietin and morphologically distinguishable cells of the bone-marrow. In uremia, protein concentration was twice higher in comparison to the normal one. The inhibiting effect of fraction F1 from the serum of patients is caused by the enlargement of level of physiological inhibitors and unspecific toxins of the cell proliferation. Those data characterising the factor detected in the fraction F1 of normal serum together with the erythrocytic chalon are discussed.     

Isolation of heparan sulfates with antithrombin III affinity and anticoagulant potency from BALB/c 3T3, B16.F10 melanoma, and cutaneous fibrosarcoma cell lines

The heparan sulfates synthesized in vitro by three cell lines were isolated by proteolysis and preparative anion exchange chromatography and purified free of other glycosaminoglycans by selective enzymatic degradation. The isolates from the medium of BALB/c 3T3 fibroblasts, B16.F10 melanoma cells, and a cutaneous fibrosarcoma line, along with that from the detergent-extracted cell layer of the fibroblasts, were affinity-fractionated on columns of matrix-immobilized human antithrombin III. Each heparan sulfate contained subfractions with high affinity for the proteinase inhibitor, ranging from 3-34% of the starting material. The high affinity species possessed measurable anticoagulant activities by a clotting assay (6 to 30 units/mg). Since none of the lines were derived from cell types having any known biological role in vascular homeostasis, we suggest that anticoagulant activity of the glycosaminoglycan is a random property of its primary structure.