It is known that the carcinogenic effect of estragole, a component of essential oils of many spicy plants, is characterized by species, tissue, and sex specificity. It causes mainly liver tumors in female mice but is not carcinogenic for male mice and for rats. In this work, the estragole hepatocarcinogenicity was shown for female mice of previously not studied ICR line. The strict correlation between estragole hepatocarcinogenicity and its ability to decrease the level of glucocorticoid induction of liver-specific enzymes tyrosine aminotransferase (TAT) and tryptophan oxygenase (TO) was found. Inhibition of TAT and TO inducibility by estragole takes place only in female mice but not in male mice and in rats. Studying the estragole effect on DNA-binding activity of transcription factors, present mainly in liver and regulating expression of genes encoding liver-specific proteins, has shown that estragole decreases FOXA and HNF4 activities but not activities of C/EBP and HNF1, and this happens only in female mice, for which this substance is hepatocarcinogen, but not in male mice and in rats. Pentachlorophenol, preventing hepatocarcinogenic effect of estragole, abolishes inhibitory influence of the latter on the TAT and TO glucocorticoid induction and restores DNA-binding activity of FOXA and HNF4. Thus, a correlation was revealed between the estragole hepatocarcinogenic effect and decrease in DNA-binding activity of transcription factors FOXA and HNF4, which might be indicative of the role of these factors in tumor suppression mechanisms in liver.
The authors give a short survey of previous results on δ-homogeneous Riemannian manifolds, forming a new proper subclass of geodesic orbit spaces with nonnegative sectional curvature, which properly includes the class of all normal homogeneous Riemannian manifolds. As a continuation and an application of these results, they prove that the family of all compact simply connected indecomposable δ-homogeneous Riemannian manifolds with positive Euler characteristic, which are not normal homogeneous, consists exactly of all generalized flag manifolds Sp(l)/U (1) · Sp(l − 1) = CP 2l−1 , l ≥ 2, supplied with invariant Riemannian metrics of positive sectional curvature with the pinching constants (the ratio of the minimal sectional curvature to the maximal one) in the open interval (1/16, 1/4). This implies very unusual geometric properties of the adjoint representation of Sp(l), l ≥ 2. Some unsolved questions are suggested.2000 Mathematical Subject Classification: 53C20 (primary), 53C25, 53C35 (secondary).
The possibility of obtaining of surface layers on low-carbon steel 20 by high-energy methods is shown. The features of structure formation in the surface layers after atmospheric electron-beam deposition of iron-graphite powder mixture and high-frequency current treatment are considered. It is shown that coatings with thickness of 2.6 mm and hardness of up to 8000 MPa are formed during atmospheric electron beam deposition. High-frequency current treatment allows to obtain coatings with thickness from 500 to 1600 μm, which hardness reaches 7000 MPa. Hardness increased is due to the formation of hypoeutectic cast iron structure or hypereutectoid steel during high-energy treatment, depending on the processing modes. It is expected that the increase in surface hardness will positively affect the wear resistance of high-carbon coatings.
We performed clinical and morphological examination of 59 women with internal endometriosis (adenomyosis). Women were found to develop adenomyosis more frequently in the perimenopausal period (in their 40s) after repeated abortions and diagnostic surgical procedures. In 90% patients, adenomyosis was associated with the formation of multiple leyomyomatous nodules; glandular hyperplasia of the endometrium and fibrocystic transformation or fibrous degeneration of the ovaries were found in 60 and 100% cases. Two morphological variants of adenomyosis were identified: invasion of cytogenic stroma into the underlying myometrium with the formation of endometrial glands and invasion of cytogenic stroma via connective tissue interlayers without formation of endometrial glands and with pronounced neoangiogenesis. Foci of active adenomyosis in the uterus with predominance of cytogenic stroma were most prevalent in the late reproductive period. Endometrioid heterotopias were accompanied by considerable structural and functional reorganization of the myometrium with the formation of multiple leyomyomatous nodules. The presence of active and inactive adenomyosis foci and leyomyomatous nodules in uterus specimens reflects their metachronous development.
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