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1.
Development of ovaries in bovine fetuses   总被引:1,自引:0,他引:1  
The growth of ovaries, development of germ cells, formation of sex cords, folliculogenesis and dependence of these processes on the gonad morphogenesis stages were studied on 68 embryos and foetuses at the age of 1.5 to 9 months. Sex differentiation of ovaries was shown to take place in 1.5 month old embryo. The cords of connective tissue's cortical stroma appear also in 1.5 month old embryo, they develop in the dorsoventral direction and reach the gonad's covering epithelium in 6 month old foetuses. The formation of the medulla rudiment starts in 1.5 month old embryo when the gonad is separated from mesonephros and connected with it via the ovary gate. In 4 month old foetuses the ovary net transforms into a stellate structure. Important morphogenetic processes, such as the development of the ovary somatic elements, entry of the oocytes into meiotic prophase, formation of the sex cords and folliculogenesis, develop in the dorsoventral direction Germ cells in 9 month old foetuses are enclosed into primordial or, growing follicles.  相似文献   
2.
Chromosome despiralization and nucleolus vacuolization have been studied during the oocyte intensive growth. Oocyte and nucleolus growth has been found to stop at the secondary antral follicles with the diameter more than 1000 mkm. Chromosomal and nucleolar activity decreases at this stage. Chromosomes condense and concentrate around the nucleolus and chromatine mass (karyosphere) forms.  相似文献   
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Melanoma is the most lethal cutaneous cancer with a highly aggressive and metastatic phenotype. While recent genetic and epigenetic studies have shed new insights into the mechanism of melanoma development, the involvement of regulatory non‐coding RNAs remain unclear. Long non‐coding RNAs (lncRNAs) are a group of endogenous non‐protein‐coding RNAs with the capacity to regulate gene expression at multiple levels. Recent evidences have shown that lncRNAs can regulate many cellular processes, such as cell proliferation, differentiation, migration and invasion. In the melanoma, deregulation of a number of lncRNAs, such as HOTAIR, MALAT1, BANCR, ANRIL, SPRY‐IT1 and SAMMSON, have been reported. Our review summarizes the functional role of lncRNAs in melanoma and their potential clinical application for diagnosis, prognostication and treatment.  相似文献   
4.

Background

The liver is an important organ for its ability to transform xenobiotics, making the liver tissue a prime target for toxic substances. The carotenoid bixin present in annatto is an antioxidant that can protect cells and tissues against the deleterious effects of free radicals. In this study, we evaluated the protective effect of bixin on liver damage induced by carbon tetrachloride (CCl4) in rats.

Results

The animals were divided into four groups with six rats in each group. CCl4 (0.125 mL kg-1 body wt.) was injected intraperitoneally, and bixin (5.0 mg kg-1 body wt.) was given by gavage 7 days before the CCl4 injection. Bixin prevented the liver damage caused by CCl4, as noted by the significant decrease in serum aminotransferases release. Bixin protected the liver against the oxidizing effects of CCl4 by preventing a decrease in glutathione reductase activity and the levels of reduced glutathione and NADPH. The peroxidation of membrane lipids and histopathological damage of the liver was significantly prevented by bixin treatment.

Conclusion

Therefore, we can conclude that the protective effect of bixin against hepatotoxicity induced by CCl4 is related to the antioxidant activity of the compound.  相似文献   
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Sixty preparations of basidiomycetes (Ganoderma, Lentinus, Pleurotus, Laetiporus, Polyporus, Inonotus, Flammulina, Grifola, Trametes) were investigated with respect to their toxicity for Vero cells and antiviral activity. The antiviral activity was estimated with the use of the West Nile virus and type 2 Herpes simplex. It was shown that 11 preparations of Ganoderma, Lentinus and Pleurotus completely inhibited the infective activity in doses not lower than 1000 TCD50 (the West Nile virus) and 100 PPU (type 2 Herpes simplex). The antiviral activity of the preparations was likely due to the content of polysaccharides or their derivatives in the composition. It increased with increasing of the quantity of the total polysaccharide fraction or its concentration.  相似文献   
7.
In 50 intact white rats at the age of 6, 15, 23 and 30 months synapsoarchitectonics of the celiac plexus nodes was studied by an electron microscopy method. Peculiarities in synapsoarchitectonics are stipulated by pericaryon processes in neurons, some of them have no contacts with the axonal terminals, while others have contacts with the axonal terminals. The former include small (about 0.5 mkm) drop-like and large (up to 1.5 mkm) polymorphous processes within the limits of perisomatic membrane, as well as processes penetrating the neuronal capsule. All of them contain, in different combinations, vesicles, ribosomas, fibrillae, and the largest processes--small cisterns of granular cytoplasmatic network and single mitochondria. The processes of the first group are considered as original stages for the development of the second group processes. The latter are represented by different in size (about 1.0--2.0 mkm) in form (digital, cone-, pin-, goblet-shaped, cylindrical, branching) and in content formations. There is, as a rule, one contact on the processes of an uncomplicated form, while on the branching processes there can be up to three and more contacting axonal terminals. Peculiar features in the composition of the processes taken as a whole (specific forms, absence of dendritic tubes, sometimes numerous contacts with axonal terminals in spite of small size) distinguish them from newly forming dendritic processes and these formations are considered as independent specialized receptor apparatus in the pericaryon of neurons of the celiac plexus.  相似文献   
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