[Comparative study of the proliferative activity of blood vessel cells of various calibers].

Proliferative activity of the main tissue components of aorta, inferior vena cava and small vessels of paravasal tissues has been studied in 7 white adult rats after repeated injections of 3H-thymidine (12 injections of 0.8 microCi/g with the interval of 8 h). The greatest number of labelled endotheliocytes is revealed in capillaries, small and medium veins (29.

DNA and sex chromatin content in nuclei of conductive system and working myocytes of normal and hypertrophied human heart.

DNA content was measured by means of Feulgen cytophotometry in myocyte nuclei of sinoatrial und atrioventricular nodes, Purkinje cells, left and right atria and ventricles from normal and hypertrophied human hearts both on 12 microns sections and on squash preparations of myocardial tissue. In contrast to ordinary atrial and ventricular myocytes of normal and hypertrophied adult hearts, which contain mostly polyploid nuclei, the DNA content in 74 to 88.5% of myocyte nuclei from sinoatrial and atrioventricular nodes does not exceed 2 c.

[Biosynthetic activity of parathyroid cells during different function of the parathyroid glands].

By means of autoradiograph c and morphometric methods parathyroid glands of 31 rats after single injection of 3H-leucin (2,5 mc Cu/g of body mass 25 min. before killing) were investigated. Parathyroid glands were inhibited by multiple injections of calcium gluconate solution or by a diet with increased content of calcium and vitamin D2.

[A morphometric study of myocytes of normal and hypertrophic human atria].

Morphometric study of myocytes of normal and hypertrophic human atria was performed in semithin and paraffin sections. The hypertrophy is followed by the increase of size of both the myocytes and their nuclei: the average nuclei diameter increases from 5.9 to 7.

[Restorative processes in the parathyroid glands in experimental hypothyroidism].

By means of morphological, morphometrical and autoradiographical methods restorative processes in the parathyroid glands in 41 euthyroid and in 41 hypothyroid rats have been studied during 1-24 days after mechanical trauma of the glands or after hemithyroparathyroidectomy. Seven hypothyroid and 7 euthyroid rats serve as a control. Hypothyroidism is produced with daily injection of mercazolil (6 mg/kg) 3 weeks before the operation and during the time of the experiment.

[Acetylcholinesterase expression and changes in the electrical excitability of neuroblastoma cells during their morphological differentiation induced by an increase in the pH of the medium].

Inhibition of cell division and outgrowth of neurites with average rate of 31.5 +/- 4.4 micrometers per hour were observed in neuroblastoma cultures of the Neuro 2a clonal line 24 hours after the increase in the culture medium pH from 7.

[Proliferative activity of typical thyrocytes and C cells in normal and regenerating thyroids].

By means of quantitative methods (autoradiography, estimation of the mitotic index of cells, morphometry) proliferative activity of typical (follicular) thyrocytes and C cells (calcitonicytes) has been studied in 40 rats both in control and in 1-30 days after hemithyroidectomy. For revealing C cells silver nitrate impregnation after Sevier-Munger and metachromatic reaction with toluidine blue in Sawicki's modification have been used. At repeated injections of 3H-thymidine (12 injections of 0.

[Levels of DNA and sex chromatin bodies in the myocyte nuclei of different sections of the human heart].

Nuclei of ventricular, atrial and atrioventricular node myocytes of normal and hypertrophied human heart were studied on squash preparations and on 12 micron sections after the Feulgen staining. The cytophotometric DNA measurements have shown a distinction in the degree of polyploidization of nuclei in different heart compartments. In contrast to ventricular and atrial myocardia, in which polyploid nuclei predominate, the conduction system myocytes contain 77-88% of diploid nuclei.

[Phenotypic characteristics of heat-resistant murine neuroblastoma cells].

One-step selection of murine neuroblastoma (N18TG2 cell line) for the resistance to injuring action of higher temperature resulted in obtaining cell line NTR1 stably capable of proliferating at 40 degrees C. The thermoresistance is shown to be coupled with the changes in some phenotypic features of NTR1 cells: the multiplication rate, saturation density of cells, morphological features, inducibility of long neurite-like processes and adhesion. A possible significance of plasma membrane changes in genetically stable thermoresistance of NTR1 neuroblastoma cells is discussed.

[Regeneration of the parathyroid glands in experimental hyperthyroidism].

By means of morphological, morphometric and radioautographic methods, regeneration of mechanically traumatized parathyroid glands has been studied in 22 euthyroid and 22 hyperthyroid rats on the 1st-20th days after the operation. The thyroid gland is stimulated by daily injection of thyrotropin (1 ME/100 g of body mass). Twelve non-operated animals (6 hyperthyroid and 6 euthyroid rats) serve as control.

[Spatial organization of proliferative processes in the parathyroid glands upon acute stimulation of parathyroid function].

A quantitative analysis on homogeneity degree in distribution of proliferating parathyrocytes in the parathyroid glands under conditions of an acute stimulation of their function, produced by bilateral nephrectomy (12 rats, 50-70 h after the operation) and by hemiparathyroidectomy (12 rats, 2-3 days after the operation) have been performed. Six intact animals serve as the control. In order to reveal proliferating cells, 1 h before sacrifice 3H-thymidine (1 mc Ci/g) is injected intraperitoneally, and to some animals--colchicine (1 mg/kg) is injected 6 h before the sacrifice.

[Proliferation of poorly differentiated cells in the rat liver after a single injection of the hepatocarcinogen 4-dimethylaminoazobenzine and its noncarcinogenic analog].

With the aid of autoradiography, the proliferation of non-differentiated (oval and transitional) cells in rat liver induced by a single injection of hepatocarcinogen 4-dimethylaminoazobenzene and its non-carcinogenic analogue has been studied. These cells are characterized by a high proliferative activity reaching its maximum 4 days after injection of both the agents. Later on, the proliferative activity decreased due probably to differentiation of such cells.

[Quantity of DNA, sex chromatin bodies and nucleoli in the nuclei of the muscle cells of normal and hypertrophied human atria].

Nuclei of myocytes of normal and hypertrophied human heart atrium were studied on squash preparations. Judging by the sex chromatin body pattern, it is the polyploidization that is responsible for the increased DNA contents in these nuclei. The cytophotometric DNA measurements demonstrated the up to 93% occurrence of polyploid nuclei even in myocytes of normal atrium.