Biometric studies of the aorta, endocrine glands (testes, prostate, and thyroid), and x-ray examination of the hands from 427 corpses of men and women aged 17-89 years helped formulate equations of paired and multiple linear regression for the diagnosis of age. The difference between biological and passport age is significant if the diagnosis is made on the basis of a single object or single sign. Complex use of several objects described by many signs is recommended; in this case the confidence intervals is no more than +/- 4.09 years.

Adolescent↗

PubMedDate not supplied

[Thyroid morphofunctional changes in various types of experimental chronic stress].

Structural and functional parameters of the thyroid were studied in mature rabbits, inducing stress by stimulating the ventromedial nucleus of the hypothalamus or by exposing the animals to electrocutaneous irritations. Morphometric and radioimmunoassay results have revealed thyroid activation during the adaptation syndrome. Prolonged intensive stress was shown to cause a decrease in thyroid secretory activity, reflecting change of a stage of stable resistance by a phase of depletion of compensatory resources. However the nature of changes in the blood levels of thyroid and thyrotropic hormones in experimental animals have some characteristic features. A conclusion was made of the correlation between pathogenesis of the general adaptation syndrome and a methodological approach to simulation of a body tension reaction.

Adaptation, Physiological↗

PubMedDate not supplied

[Effect of calcium-regulating hormones on the secretory activity of basophils of the thyroid and parathyroid glands].

The purpose of the study was to compare the secretory activity of thyroid and parathyroid mast cell populations during a rise of the level of calcium regulating hormones in the body. 65 rats were divided into 5 equal groups. The animals were given single intraperitoneal injections of the following agents: the 1st group--parathyroid hormone, 5 units per 100 g of body mass; the 2nd group--trilon B, 0.5 ml of 5% solution; the 3rd group--calcitonin, 1.5 units per 100 g of body mass; the 4th group--calcium gluconate, 0.7 ml of 10% solution; the 5th group--distilled water, 0.7 ml; after that the animals were killed with a 12 min. interval. The index of mast cell degranulation was calculated in the thyroid and parathyroid. The administration of PTH and trilon B caused a significant increase in parathyroid mast cell degranulation 36-120 min. after injection whereas secretory activity of thyroid tissue basophils did not change. Mast cell populations of both glands reacted in a similar way to the administration of calcitonin and calcium gluconate expressed in significant enhancement of degranulation 24-84 min. after injection. The results obtained indicated an important role of thyroid and parathyroid tissue basophils in the implementation of inter- and intraorganic regulatory interactions.

Animals↗

PubMedDate not supplied

[Cytological mechanisms of the growth and regeneration of the parathyroid glands].

Contribution of proliferation and hypertrophy of the epitheliocytes to the growth and regeneration of the rat parathyroid glands was estimated using organo- and cytometry, cytophotometry of DNA content in the nuclei and determination of mitotic index. During postnatal development and in the case of hypertrophy of the adult glands following a moderate resection (50%), the gland growth is provided by mitotic divisions of the parathyroid cells, rather than by the increase in cell size. When up to 75 and 90% of the gland volume is removed, cell hyperplasia is accompanied by stable hypertrophy of the parathyroid cells unrelated to their polyploidization. The contribution of nonmitotic cell hypertrophy to the total increment of the organ volume amounts to 40-50%.

Animals↗

PubMedDate not supplied

[Factors increasing the safe time of induced heart arrest in hyperbaric oxygenation and normothermia].

Explore the source record for details and available documents.

Animals↗

PubMedDate not supplied

[Morphometric analysis of the parathyroid glands and thyroid gland C-cells during prolonged administration of triiodothyronine and mercazolyl].

The aim of the study was to perform a systemic morphometric analysis of the parathyroid glands and parafollicular thyrocytes under the conditions of the suppression of function of the thyroid follicular apparatus. Water suspensions of triiodothyronine and methniasole were administered through a probe for 24 days to adult albino male rats (6 in each group) at daily doses of 50 micrograms/kg and 6 mg/kg respectively; 6 animals were controls. The level of total calcium in the blood serum of animals in the study groups did not differ from control values. The administration of the drugs induced the development in the parathyroid glands of morphological signs of their increased function (hypertrophy of the parathyrocytes, their nuclei and cytoplasm in both series of experiments, an increase in the mean count of nucleoli in the nucleus in the administration of triiodothyronine). Signs of elevated secretory activity of the population of parafollicular thyrocytes (a decrease in the relative frequencies of C-cells with the cytoplasm filled in with secretory granules; an increase in the proportion of cells with cytoplasmic zones at the vascular poles free of granules) were detected in the thyroid.

Animals↗

PubMedDate not supplied

[Prevention of cholera transmission by way of food and food products].

Explore the source record for details and available documents.

Cholera↗

PubMedDate not supplied

[The cytological mechanisms of the postnatal growth of aortic endothelium].

Contribution of proliferation and hypertrophy of endotheliocytes to the postnatal growth of the internal aortic lining in rats was estimated using organo- and cytometry, cytophotometry of nuclear DNA, radioautographic analysis of 3H-thymidine incorporation, determination of the mitotic index and the number of binucleated cells. Mitotic divisions of diploid endotheliocytes (in adult rats, their proportion attains 97-98%) is the principal cytological mechanism that, throughout the life of an animal, provides for an increase in the area of endothelial layer. Cell hypertrophy, which is unrelated to polyploidization, develops only during the first month of postnatal life. In old rats (2.5 years of age), an increased proportion of binucleate cells (2c x 2) and cells with pycnotic nuclei is observed.

Aging↗

PubMedDate not supplied

[Thyroid regeneration in various localizations of resected fragments of the organ].

Structure and function of the regenerating thyroid fragment were studied in 18 adult white rats 30 days after partial resection of centromedial or peripheral fragments of the lobes similar in size using quantitative methods (organometry, histometry, measurements of blood serum hormones). The volume of glandular tissue removed in two series of experiments was 40 and 75% of the total thyroid mass of experimental animals. Centromedial portions of the thyroid of intact rats were characterized by greater follicular epithelium volume (by 10%) and C-cell content per section area (six-fold), as well as by a lesser mean diameter of the follicles (by 26%) and colloid volumic fraction (by 40%) in comparison with the peripheral segments. No reliable differences in the quantitative structural parameters (mass, tissue component volumic fractions, mean follicular diameter and follicular epithelium height) and hormonal activity of the regenerated tissue in the two variants of surgery were observed. The results indicate that thyroid parenchyma of various portions of the organs is similarly capable of full-value regeneration.

Animals↗