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Biomedical subjects

A V Pavlov

Publications and source records attributed to A V Pavlov.

At least 19 recordsLinked to original sources
PubMed1992

[The mitotic activity of the follicular and parafollicular (C) cells in the thyroid of rats with hypercalcemia].

Slices of the thyroid gland were impregnated with silver nitrate and stained with hematoxylin. Separate calculation of the index of calchicin mitosis of the follicular and parafollicular (C-) cells was made. The material of 37 mature albino rats was analyzed. Calcium-rich diet was given to 22 animals during 10 days. Different levels of hypercalcemia were achieved by different doses of vitamin D2 (from 1 to 10 thousand MU daily, 11 experimental groups). The mitotic index of C-cells was found to grow but under mild hypercalcemia (10% of the control level). Further elevation of the calcium concentration in blood was followed by a decrease of the amount of the dividing parafollicular cells down to control values. In rats fed by the diet optimal for the stimulation of C-cells division (11 rats, 2000 MU as a daily dosage of vitamin D2) within the interval from 1 to 10 days increased mitotic activity of the follicular cells was found from the 3rd day, while that of C-cells only as late as the 9th-10th day. In all the experimental rats the mitotic index of the follicular thyrocytes was 3.5-4 times as high as the mitotic index of C-cells. Relatively not high proliferative activity of parafollicular cells might be due to their pronounced polyfunctional character and their participation in complex paracrine interactions with other cell elements of the thyroid gland.

Animals↗
PubMed1991

[Protection from foot-and-mouth disease virus in naturally-susceptible animals by a linear polymer of a synthetic peptide].

Linear polymer of a peptide corresponding to the fragment 142-155 of the foot-and-mouth disease virus A22(550) protein (VP1) was synthesized. Whereas the monomeric peptide was only slightly immunogenic, the polymer induced virus-neutralizing antibodies in rabbits and protected 100% guinea pigs. Sheep vaccinated once and cattle vaccinated twice were stable against infection with the homologous virulent foot-and-mouth disease virus.

Amino Acid Sequence↗
PubMed1990

[Effects of cordarone on the contractile function of the left ventricle].

Acute intravenous administration of cordarone in a dose of 5 mg/kg was demonstrated to decrease the mean values of the peak increase rate in left ventricular pressure, circulatory myocardial fiber shortening velocity, ejection fraction, and specific peripheral vascular resistance by 19.5, 12.3, 10.3, and 26.2%, respectively. Less marked changes occurred in stroke and cardiac outputs. The effects were more pronounced during a more rapid intravenous administration of the agent, as well as in patients with lower myocardial contractility. Chronic administration of oral cordarone in doses of 200 to 300 mg a day had a low effect on cardiac hemodynamic parameters. Sinus bradycardia was significant in reducing the cardiac output (-10.8%). All the patients displayed prolonged Q-T interval that was maximally apparent in patients with the baseline prolonged interval (+13.1%).

Amiodarone↗
PubMed1989

[Cellular renewal in the parenchyma and stroma of the parathyroid glands].

By means of autoradiographic, morphometric and cytophotometric methods main parameters, characterizing processes of cellular renewal have been studied in the parathyroid glands of 66 mature white male rats with body mass of 160-230 g. The time of renewal of the parathyrocyte population is 80-100 days, the average daily mitotic index--0.88 +/- 0.09% 0, the average duration of mitosis--1.61 h, the average daily index of dying cells--0.24 +/- 0.03% 0. The greatest mitotic activity of parathyrocytes is revealed in the evening and early in the morning. At night together with decreasing amount of dividing cells, content of dying parathrocytes increases. The glandular cell population is mainly diploid, polyploid cells make no more than 0.1%. The time of renewal of stromal cells makes 82 +/- 9 days. The results obtained demonstrate that the parathyroid cells should be considered as a slowly renewal population.

Animals↗
PubMed1989

[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. Parathyroids were stimulated by multiple injections of Trilon B solution, by a diet with increased content of phosphates or by subtotal parathyroid resection. Straight correlation between parathyroid function, average section area of parathyrocytes and average number of silver granules per one parathyrocyte was revealed. Hence, average section area of parathyrocytes is objective morphometric criterion of parathyroid function.

Animals↗
PubMed1988

[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 0.8 mcCi/g with the interval of 8 h) in the intact rat thyroid glands and equal amount (2-3%) of endocrine cells of the both types are labelled, in 2.5-6 days after a partial resection, amount of the labelled follicular cells increases by 10 times, while that of calcitonicyte--only by 2 times. The differences revealed can be connected with more pronounced histogenic potencies of the typical thyrocytes, realized most fully under conditions of their specific hormonal stimulation in the course of the gland restoration.

Animals↗
PubMed1978

[Reparative processes in the liver and adrenal cortex of rats following an experimental vascular crisis].

Reparative processes in the liver and the adrenal cortex of hemiadrenalectomized female rats, which sustained an acute circulatory disturbance as a result of orthostasis, were investigated by means of quantitative methods (cytometry, kariometry, nucleolometry, determination of cell content calculation of nucleo-cytoplasmic, nucleolo-nuclear ratios). Common features in regeneration of the organs under study were found. During the first days of the experiments the count of the dying cells increased and simultaneously the quantity of amitoses and binucleated cells in the liver grew. The cell composition of the organs was stabilized by the 15th day in the adrenal gland and by the 45th day in the liver. During the first week after orthostasis mitotic activity of epithelial cells rose in both the organs. Later the regeneration took place at the intracellular level (activation of the nuclear apparatus and hypertrophy of the cell cytoplasm).

Acute Disease↗
PubMed1978

[Cellular composition of different zones in the rat and rabbit hepatic lobule under normal and experimental conditions].

Different types of hepatocytes (with caryopycnosis and caryolysis, at the state of mitosis, with amitotic nuclear strangulation and with two nuclei) were counted in the central, middle and peripheral zones of the hepatic lobule in rats subjected to an acute aminosin intoxication, and in rabbits after compressing soft tissues of the extremities. Time of observation--1--90 days in the rats and 10 h--20 days in the rabbits. In the zones of the hepatic lobule with the greatest degree of damage, the number of cells with caryopycnosis and caryolysis, as well as the number of hepatocytes with amitotic nuclear strangulation and binucleated cells were especially great. Mitotic activity of the hepatic cells was about 0.49% in the rats and 0.07% in the rabbits. Regardless the place of the damage in the hepatic lobule in all the zones, there was a definite correlation between the amount of cellular forms reflecting the demage and destruction of hepatocytes and their restoration, the same as observed in certain zones of the intact hepatic lobule.

Acute Disease↗
PubMed1977

[Ocular scale for logarithmic grouping of classes of spherical nuclei and measurement of the diameters of their nucleoli].

The proposed scale is prepared by a photographic method and consists of some vertical lines, each of them being disposed at the distance equal to a nucleus diameter having bordering size between classes of lg mkm2, and of three horizontal lines, forming two patterns designated for measuring diameters of nucleoli. The scale is meant for working with the objective 90 X and the ocular 20 X and makes the measuring of nuclei and nucleoli diameters 2--2,5 times quicker as compared with the screw ocular micrometer with a sufficient coincidence of results, obtained by both methods.

Cell Nucleolus↗