[Changes in the chromatin structure of the thyroid cells related to the expression of the thyroglobulin gene]. / Izmeneniia struktury khromatina tireoidnykh kletok, sviazannye s ékspressiei gena tireoglobulina.

A highly purified thyroglobulin mRNA was isolated from human nodal euthyroid goiter. A full-length cDNA was synthesized from 33S RNA by using reverse transcriptase in the presence of human placenta ribonuclease inhibitor. A DNA complementary to human Tg mRNA was used in liquid hybridization experiments to quantify Tg mRNA. The amount of Tg mRNA in euthyroid nodal and congenital goiter was reduced. In thyroid cancer Tg specific mRNA was absent. Direct correlation between Tg gene expression in thyroid cells and DNAase-I hypersensitivity of chromatin from the thyroid gland nucleus was revealed.

[Thyroglobulin gene expression in human thyroid cells in various types of thyroid pathology]. / Ekspressiia gena tireoglobulina v kletkakh shchitovidnoi zhelezy cheloveka pri nekotorykh vidakh tireoidnoi patologii.

Highly purified thyroglobulin mRNA was isolated from human nodal euthyroid goiter. Full length cDNA was synthesized from 33S RNA by using reverse transcriptase in the presence of human placenta ribonuclease inhibitor. DNA complementary to human Tg mRNA was used in liquid hybridization experiments to determine the quantity of Tg mRNA. The amount of Tg mRNA in euthyroid nodal and congenital goiter was reduced. Tg specific mRNA was absent in thyroid cancer cells.

[Mapping of the thyroglobulin gene in high molecular weight DNA from the human thyroid in normal conditions and in thyroid pathology]. / Kartirovanie tireoglobulinovogo gena v sostave bysokomolekuliarnoi DNK shchitovidnoi zhelezy cheloveka v norme i pri tireoidnoi patologii.

A highly purified thyroglobulin (Tg) mRNA was isolated from human nodal euthyroid goiter. Ultracentrifugation in a 5-20% sucrose density gradient revealed that the protein has a sedimentation coefficient of 33S. cDNA was synthesized from the 33S RNA, using reverse transcriptase in the presence of a human placental ribonuclease inhibitor. In order to detect the polymorphism of restriction fragment length, screening of high molecular weight DNA from normal human thyroid gland and from nodal euthyroid and diffuse toxic goiters was carried out, using Tg cDNA probes and plasmid DNA containing a Tg cDNA fragment. After restriction with endonuclease Hind III, three Tg-containing fragments were identified both in the normal and nodal euthyroid goiters, whereas restriction with endonuclease Bam HI revealed two Tg-containing fragments in nodal euthyroid and diffuse toxic goiters.

[Determination of the ratio of membrane-bound and free polyribosomes and of the content of thyroglobulin in these fractions in normal thyroid gland cells and in several types of thyroid diseases]. / Opredelenie sootnosheniia membranosviazannykh i svobodnykh poliribosom i soderzhaniia v étikh fraktsiiakh tireoglobulinovykh poliribosom v kletkakh shchitovidnoi zhelezy v norme i pri nekotorykh vidakh tireoidnoi patologii.

The ratio of membrane-bound and free polyribosomes in thyroid gland cells was decreased two-fold in nodular euthyroid goiter and five-fold--in Hashimoto thyroiditis; a slight increase in thyroglobulin synthesis in free polyribosomes was noted in goiter. Impairments in transfer of the translation products across membranes of rough endoplasmic reticulum may be one of the causes of deteriorations in thyroglobulin synthesis in goiters.

[Thyroglobulin biosynthesis and the content of thyroglobulin polyribosomes of the thyroid gland cells in the normal state and in various types of thyroid pathology]. / Biosintez tireoglobulina i soderzhanie tireoglobulinovykh poliribosom v kletkakh shchitovidnoi zhelezy v norme i pri razlichnykh vidakh tireoidnoi patologii.

The content of polyribosomes in human thyroid cells was studied in health and different forms of thyroid pathology. In thyroid pathology, thyroglobulin (TG) polyribosome content in thyroid cells diminished in the following order: diffuse toxic goiter greater than mixed euthyroid goiter greater than nodular toxic goiter greater than Hashimoto's goiter and complete absence of TG synthesizing polyribosomes in thyroid cancer and congenital goiter cells. No correlation was revealed between polyribosome TG content and thyroid function. It is inferred that impairment of TG biosynthesis in thyroid diseases is related to the decreased content of polyribosome TG in thyroid cells.

[Protein biosynthesis and thyroglobulin polyribosome content of thyroid cells in congenital goiter]. / Biosintez belkov i soderzhanie tireoglobulinovykh poliribosom v kletkakh shchitovidnoi zhelezy pri vrozhdennom zobe.

The basic protein, synthetized in a cell-free (S 30) protein-synthetizing system from the thyroid cells in congenital goitre, is thyroalbumin, while 19S thyroglobulin synthesis is sharply reduced. Determination of the population extent of thyroglobulin polyribosomes has shown that they are practically absent in congenital goitre. It is suggested that thyroglobulin deficit in congenital goitre is provoked by deficiency in functioning thyroglobulin mRNA.

[Albumin mRNA from rat liver cells. Analysis of immunoadsorption of individual polyribosomes]. / Al'buminovaia mRNK iz kletok pecheni krysy. Analiz protsessa immunosorbtsii individual'nykh poliribosom.

The analysis of albumin polyribosomes immunoadsorption is carried out using "sandwich" immunoadsorbents prepared on the basis of two aminobenzylcelluloses: commercial (paraaminobenzylcellulose) and synthesised (methaaminobenzyloxymethylcellulose). A method is worked out which is good for the estimation of the adaptibility of different aminobenzylcellulose preparations as an insoluble basis for the immunoadsorbent. Major properties of the "sandwich" sorbent (the accessible capacity and specificity) and the percent of isolated individual polyribosomes are found to be interrelated and determined by conditions of the immunoadsorption reaction. The increase of polyribosomes and sorbent concentrations and their ratio in the incubation medium results in the increase of the sorbent accessible capacity and the decrease in the inspecific adsorption but at the same time the percent of adsorbed polyribosomes decrease too. The "excess" of adsorbent with respect to polyribosomes, participating in the binding reaction, is necessary for the quantitative isolation of individual polyribosomes.

[A study of thyroglobulin biosynthesis by the incorporation of glucosamine-14C, mannose-14C and galactose-14C in thyroid gland cell-free systems]. / Issledovanie biosinteza tireoglobulina po vkliucheniiu gliukozamina-14C, mannozy-14C i galaktozy-14C v beskletochnoi sisteme schitovidnoi zhelezy

The authors studied in the microsomal and polyribosomal protein-synthesizing system of the thyroid gland a combination of carbohydrate components of thyroglobulin by the incorporation of labeled D-glucosamine-14C, D-mannose-14C, and galactose-14C. It was shown that in the process of protein biosynthesis there occurred in the microsomal system a combination of carbohydrate-14C; no combination of carbohydrates was noted in the polyribosomic system. Analysis of the synthesized proteins was carried out by disc-electrophoresis. All the carbohydrates under study were revealed both in the 19S molecule of thyroglobulin and in its 3-8 subunits. Thus, a combination of carbohydrate components occurred after the termination of peptide chain synthesis and already at the microsome level.

[Synthesis of thyroglobulin in the polyribosome cell-free system of the thyroid gland]. / Sintez tireoglobulina v poliribosomnoi beskletochnoi sisteme shchitovidnoi zhelezy

Protein synthesis (in particular, thyroglobulin) is studied in a cell-free system containing polyribosomes of thyroid gland. After the incubation with radioactive label, ribosomes were centrifugated, supernatant was dialyzed against 0.05 M Tris-HCl buffer, pH 7.2 for a night, concentrated by ficol and centrifugated in 5-20% linear sucrose gradient. 14C-radioactivity of 19S fraction (thyroglobulin) was shown to comprise about 25% of total radioactivity. The rest radioactivity was found in 3--8S fractions. The distribution of the radioactivity as it was shown by polyacrylamide gel electrophoresis is as follows: 27S--11.0%; 19S--14.2%; 12S--5.8% and 4S--7.6% of total radioactivity in polyacrylamide gel. It is supposed that two successive processes take place in thyroid gland: a synthesis of thyroglobulin subunits and an exchange of new synthesized subunits with presynthesized ones.

[Stimulation of the protein synthesizing capacity of thyroid gland polyribosomes in vitro under the influence of cyclic adenosine-3', 5'-monophosphate]. / Stimuliatsiia beloksinteziruiushchei sposobnosti poliribosom shchitovidnoi zhelezy in vitro pod deistviem tsiklicheskogo adenozin-3', 5'-monofosfata

It was shown that cAMP increased the capacity of polyribosomes of the thyroid glands to the labeled phenylalanine incorporation into the protein by 51 per cent. Preincubation of microsomes or ribosomes with cAMP in the cell-free protein-synthesizing system also increased the incorporation of the labeled amino acids into the protein by 54 and 49 per cent, respectively. The optimal effect occurred with the concentration of cAMP of 0.2 mg/ml. cAMP in a concentration of 0.8 mg/ml inhibited the incorporation of the labeled amino acids by 32 per cent. This can possibly be attributed to the forming products of cAMP degradation. Modification of the protein-synthesizing system (ATP--1 mM. GTP--1.6 mM) led to the fact of an increase in the level of the labeled amino acid incorporation into the protein by 54 per cent; the simulating effect of cAMP persisted. In the absence of ATP in the incubation medium addition of cAMP failed to stimulate the protein synthesis. Thus, cAMP stimulated protein synthesis in the thyroid gland in vitro, with utilization of ribonucleoproteid particles.