Folia histochemica et cytochemica最新文献

Considering the importance of Zn for normal metabolic processes as well as its neurotoxic properties when ingested in undue amounts we have undertaken a study on the effect of ZnO intoxication on the neurosecretory function of the hypothalamus and hypophysis. The investigations were performed on rats that have been treated intragastrically with ten daily (100 mg) doses of ZnO. The intoxicated rats revealed elevated contents of neurosecretion in the neurosecretory nuclei of the hypothalamus along with decline amounts of neurosecretion in the nervous parts of the hypophysis. The contents of PAS-positive substances was increased all over the neurosecretory hypothalamo-hypophyseal system. The concurrent enlargement of the nuclear and cytoplasmatic areas of the secreting cells speaks in favour of the conclusion that the observed histochemical and morphometric alterations reflect both an increased neurosecretory activity of the hypothalamus and in enhanced release of antidiuretic hormone.

Ultrastructural changes in mitochondria of liver, intestine and heart muscle immediately after irradiation with a dose of 4000 r were studied in rats. Morphometric determinations were carried out for mitochondria. The quantitative stereologic data of the irradiated mitochondria of liver and heart muscle indicated the more advanced changes as compared with those observed in the intestine. Radiation induced changes in mitochondria of enterocytes of crypts and apical villi have shown, that there are no differences between them even in stereological parameters. Although available data indicate that enterocytes of intestine crypts have more radiosensitivity than apical enterocytes. It is concluded that radiosensitivity of tissues and organs "in toto" differs from that of their mitochondria.

The structure of mitochondria in the antheridial filaments of Chara varies. At the same stage of interphase, there are half condensed mitochondria having a very dense matrix (type A) slightly swollen mitochondria with very light matrix (type D) and, most frequently, the "orthodox" mitochondria (types B and C). The heterogeneous structure of the mitochondria disappears 20 minutes after administering 2-deoxyglucose, i. e., when influenced by an elevated level of cellular ADP. During the course of the cell cycle the ratio between mitochondria A, B, C and D changes several times. These changes suggest that possible reversible conversion of one type of mitochondrion into another and this probably results from changes in the functional status of the mitochondria during different phases of the cell cycle.

Determination of quantity, distribution and topography of calcium, phosphorus, magnesium and copper in transverse and longitudinal sections of deciduous and early erupted permanent human teeth were made by the use of an x-ray microanalyser and simultaneous analysis of the microstructure of the examined surface by the use of an electron scanning microscope. The examinations demonstrated the higher content of calcium and phosphorus, greater density and more homogenous distribution of these elements in the deciduous teeth. In the permanent teeth characteristic conglomerations of mineral granules were visible in the area corresponding to the dentine tubuli.

The incorporation of 3H-thymidine was used as a means to determine the stimulation of thymus and lymph node cell populations by TSTA obtained and purified from the surface of polyoma cells in a conditioned medium with T cell growth factor. The specificity of TSTA was demonstrated after the immunization of CBA mice in adoptive transfer of lymph node cells followed by challenge with polyoma cells. The binding affinity of TSTA to receptors of lymph node cells and thymocytes from CBA mice was tested by radiolabelling. Differences in binding affinity estimated on the basis of equilibrium constant (K) and maximal binding capacity (n) were found between thymus and lymph mode cells populations but not between lymph node cells populations themselves. The lack of change in the binding affinity of 125I-TSTA to receptors of lymph node cells in various experimental mice was also discussed.

Androgen level and the activity of lactate dehydrogenase, succinic dehydrogenase, 17 beta-hydroxysteroid dehydrogenase and NADP-diaphorase was studied in cultured Leydig cells obtained from testes of male mice from inbred strains KP and CBA following a single injection of cadmium chloride. Mice from CBA strain, known to be resistant to the toxic effects of cadmium showed no differences in the enzyme activity and endocrine function of gonads, as compared with control animals. In KP mice, sensitive to cadmium, a marked decrease of activity of all studied dehydrogenases, as well as a fall of androgen level was observed following cadmium administration. The decrease of hormone secretion occurred on the 2nd day of tissue culture and showed a correlation with the 17 beta-hydroxysteroid dehydrogenase activity.

Germ cells development at particular stages of gonad differentiation during the period of fetal intrauterine life were investigated. The study was performed on 101 ovaries obtained from 76 fetuses and neonates. The earliest ovary obtained was from a 12-week old fetus, the oldest one was from a full-term fetus. The examination of germ cells was based on the analysis of the morphology and enzymatic activity. The morphology of the cells was studied by the use of light and electromicroscopy. In germ cells development three forms were distinguished: gonocytes, oogonia and oocytes. Gonocytes were observed in all the ovaries analyzed. They were found mostly among cells covering the gonad. Basing on the difference in their size, shape of nucleus and cytoplasm gonocytes were divided into older ones and younger ones. In the ovaries of fetuses, as early as the 14th week of the intrauterine life, oogonia were observed. Their fairly regular shape, abundance of cytoplasm and large nucleus, often with nucleolus, made their observation possible even in light microscopy. In the cytoplasm of regularly differentiating oogonia organelles were more numerous than in gonocytes. Oocytes constituted a more differentiated form of germ cells. In comparison to the cells surrounding them, they had a larger size, were rounded in shape and had a centrally located nucleus. In the cytoplasm separated into the surrounding space was observed. In a large number of different germ cells signs of degeneration were found. The study has confirmed that irrespective of the duration of pregnancy, all forms of germ cells are present in the fetal ovaries and that the differentiation continues throughout the whole period of intrauterine life.

Explants of nervous tissue taken up from the area of locus coeruleus from rats 3-36 days old were cultured in vitro for 15 days, and than accumulation of norepinephrine (3 X 10-8M) was studied with and without preincubation with equimolar concentration of clonidine, using histofluorescence methods. Preincubation with clonidine increased the fluorescence in neural cells, particularly those derived from young animals, in which the pattern of fluorescence appeared to resemble the observed without preincubation only in cells from older animals in addition to fluorescence in the cells, fluorescent granules appeared in neuronal processes and in structures resembling non adrenergic nerve endings. Clonidine completely inhibited norepinephrine uptake by glial cells from very young animals, and inhibited that in the glia in colonies derived from 18-24 days old rats. However, clonidine preincubation restored accumulation of norepinephrine by oligodendroglia from 36 days old rats already lost by this age, but did not affect astrocytes.

In the plasma membrane surface coat of lymphatic cells L 1210 the negatively charged residues are distributed all over the membrane and are due mainly to neuraminic acid, as revealed by neuraminidase digestion followed by cationized ferretin (CF) binding. They bind eagerly to CF but not all of them bind ruthenium red (RR). In these cells RR seems to reveal rather hyaluronic acid residues, as suggested by hyaluronidase digestion. Basing on the known characteristics of CF one can calculate that neuraminic acid residues are grouped in assemblies including no more than 32 of them and spaced from 20 to 60 nm. The hyaluronic acid residues seem to be dispersed more irregularly. The membrane constituents bearing concanavalin A receptor are distributed in assemblies as well the distances between which may range up to 350 nm. After applying osmium-ferrocyanide and tannic acid reactions the surface coat appears as a continuous layer what indicates that the contrasted molecules are distributed at distances below the practically achieved resolving power of the microscope used.

Histochemical study of mucopolysaccharides of both mucous secreting and subjacent granular cells of the epidermis of Glossoscolex uruguayensis L (Righi, 1978), has been done. Histochemical tests revealed two major types of mucous cells: large ortochromatic mucous cells and metachromatic mucous cells. The first ones possess alpha-amylase resistant, PAS-positive material, together with little mucic acid, and the latter present a very low rate of neutral mucopolysaccharides and to a variable degree, both carboxylate and sulphate mucopolysaccharides. A third cell type was also detected, presenting a frothy acid like material. Subjacent epidermal granular cells display alpha-amylase resistant, PAS-positive granules, with no acid mucus.