774 research outputs found
PALEOARCHEAN MAFIC ROCKS OF THE SOUTHWESTERN SIBERIAN CRATON: PRELIMINARY GEOCHRONOLOGY AND GEOCHEMICAL CHARACTERIZATION
The Siberian craton consists of Archean blocks, which were welded up into the same large unit by ca 1.9 Ga [Gladkochub et al., 2006; Rojas-Agramonte et al., 2011]. The history of the constituent Archean blocks is mosaic because of limited number of outcrops, insufficient sampling coverage because of their location in remote regions and deep forest and difficulties with analytical studies of ancient rocks, which commonly underwent metamorphic modifications and secondary alterations. In this short note, we report data on discovery of unusual for Archean mafic rocks of ultimate fresh appearance. These rocks were discovered within southwestern Siberian craton in a region near a boundary between Kitoy granulites of the Sharyzhalgai highgrade metamorphic complex and Onot green-schist belt (Fig. 1). Here we present preliminary data on geochronology of these rocks and provide their geochemical characterization.The Siberian craton consists of Archean blocks, which were welded up into the same large unit by ca 1.9 Ga [Gladkochub et al., 2006; Rojas-Agramonte et al., 2011]. The history of the constituent Archean blocks is mosaic because of limited number of outcrops, insufficient sampling coverage because of their location in remote regions and deep forest and difficulties with analytical studies of ancient rocks, which commonly underwent metamorphic modifications and secondary alterations. In this short note, we report data on discovery of unusual for Archean mafic rocks of ultimate fresh appearance. These rocks were discovered within southwestern Siberian craton in a region near a boundary between Kitoy granulites of the Sharyzhalgai highgrade metamorphic complex and Onot green-schist belt (Fig. 1). Here we present preliminary data on geochronology of these rocks and provide their geochemical characterization
The comparative estimation of influence of higholeic sunflower and palm oils consumption on the fatty acids content of rat liver lipids
Aim: To determine of influence of higholeic sunflower and palm oils consumption on the fatty acids content of rat liver lipids.Materials and methods: The content of liver lipids and fatty acid levels in 2 lipid fractions were determined in 3 groups of rats: 1 – fat fee ration, 2 – ration with 15 % higholeic sunflower oil and 3 – ration with 15 % palm oil. The duration of feeding was 40 days. First lipid fraction was triglycerides (TG) + ester cholesterine (EC). Second lipid fraction was free fatty acids (FFA).Results: Increase of weight was the largest for third group, and the least for second group. The content of lipids in liver was the largest for third group, and the last for first group. The content of FFA was the largest for third group. The content of ω-6 PUSFA was the largest for third group. The content ω-3 PUSFA was the largest for second group.Conclusion: Palm oil consumption leact to increase sueight, the content of lipids and ω-6 PUSFA or decrease the content of ω-3 PUSFA on liver. Higholeic acid sunflower oil increase the content of ω-3 PUSFA
Effect of dietary fats on endogenous oleic acid biosynthesis in rat liver
Aim: Determine the effect of dietary fats with different fatty acid composition on the biosynthesis of oleic acid and its metabolic precursors in the liver .
Methods: High linoleic sunflower oil (HLSO), high oleic sunflower oil (HOSO) and palm oil (PO) were used. Rats were fed a semi-synthetic fat-free diet (FFD) and fat diets containing 5 % of the above oils (instead of starch) for 30 days. Liver lipids were divided into 3 fractions: neutral lipids (NL), phospholipids (PL) and free fatty acids (FFA). The fatty acid composition of the fractions was determined by gas chromatography. The “activity” of fatty acid synthase was determined from the total content of the products of this reaction (C16:0 and C16:1). The “activity” of palmitic acid elongase was determined by the ratio С18:0/С16:0, as well as by the formula (С18:0+С18:1)/(С16:0–С16:1). The “activity” of stearic acid desaturase (SCD1) was determined by the ratio C16:1/C16:0 (SCD16) and by the ratio C18:1/C18:0 (SCD18).
Results: In rats treated with fat diets, the content of palmitic and oleic acids is reduced only in the NL fraction, and to the greatest extent when consuming the diet with HLSO. The “activity” of palmitic acid elongase increases significantly with the consumption of a diet with HLSO. SCD16 desaturase “activity” decreases with fat diet, while SCD18 desaturase “activity” increases. The level of SCD18 is significantly higher than the level of SCD16. Consumption of HLSO reduces the content of ω-3 PUFA in rat liver lipids, while the intake of HOSO increases it.
Conclusions: HLSO diet reduces the endogenous biosynthesis of oleic and palmitic acids, as determined by the analysis of the rat liver NL fraction. A fat diet reduces SCD16 “activity” but increases SCD18 “activity”, especially when fed a diet with HOSO. The diet with HLSO reduces the content of ω-3 PUFA in liver lipids
Influence of antidysbiotic drugs on the liver of rats with experimental non-alcoholic steatohepatitis
High-fat diets combined with the introduction of lincomycin causes the development of steatohepatitis. Introduction antidysbiotic drugs (pro- and prebiotics) has a therapeutic effect
Anti-inflammatory action on kidneys of rats of the preparation of polyunsaturated fatty acids (PUFA)
Background. To determine the renoprotective effect of PUFA.
Methods. The preparation of essential PUFA “Liposan-C” was used, which was administered to rats on a fat-free diet in an amount of 1% of the diet weight for 32 days. The activity of elastase, urease, lysozyme, catalase and the content of MDA were determined in the homogenate of the kidneys. According to these indicators, the degree of dysbiosis and intensity of inflammation were calculated.
Results. A decrease in the activity of urease, elastase and the degree of dysbiosis in rats treated with Liposan-C was established.
Conclusion. The drug PUFA "Liposan-C" has anti-inflammatory, antimicrobial and anti-disbiotic effect on the kidneys
Human Genes Encoding Transcription Factors and Chromatin-Modifying Proteins Have Low Levels of Promoter Polymorphism: A Study of 1000 Genomes Project Data
The expression level of each gene is controlled by its regulatory regions, which determine the precise regulation in a tissue-specific manner, according to the developmental stage of the body and the necessity of a response to external stimuli. Nucleotide substitutions in regulatory gene regions may modify the affinity of transcription factors to their specific DNA binding sites, affecting the transcription rates of genes. In our previous research, we found that genes controlling the sensory perception of smell and genes involved in antigen processing and presentation were overrepresented significantly among genes with high SNP contents in their promoter regions. The goal of our study was to reveal functional features of human genes containing extremely small numbers of SNPs in promoter regions. Two functional groups were found to be overrepresented among genes whose promoters did not contain SNPs: (1) genes involved in gene-specific transcription and (2) genes controlling chromatin organization. We revealed that the 5′-regulatory regions of genes encoding transcription factors and chromatin-modifying proteins were characterized by reduced genetic variability. One important exception from this rule refers to genes encoding transcription factors with zinc-coordinating DNA-binding domains (DBDs), which underwent extensive expansion in vertebrates, particularly, in primate evolution. Hence, we obtained new evidence for evolutionary forces shaping variability in 5′-regulatory regions of genes
Development of dysbiosis in the organism of rats receiving a high-fat diet
Background. To determine the effect on the degree of dysbiosis in the organs and tissues of rats treated with high-fat diet (HFD) using fats with various fatty acid compositions.Methods. We used ordinary (high-linoleic) sunflower oil, high-oleic sunflower oil, butter, palm and coconut oils. Rats were fed with 15 % of each of the fats for 64 days. In the blood serum from v.cava and v. porta, in the liver, heart, brain, skeletal muscles and intestinal mucosa, urease activity (an indicator of bacterial insemination), lysozyme activity (a factor of non-specific immunity) were determined, and the degree of dysbiosis was calculated from the ratio of relative urease and lysozyme activities. Results. The activity of urease in the blood of v. porta increased in rats treated with HFD, and was significantly higher than in the blood of v.cava. In most of the studied tissues, urease activity increased after HFD, with the exception of rats receiving high-oleic sunflower oil (HOSO). In contrast, lysozyme activity was reduced in most tissues, with the exception of rats treated with HOSO. The degree of dysbiosis increased after HFD with the exception of rats treated with HOSO.Conclusion. HFD increases the translocation of bacteria from the intestine. The liver partially neutralizes the microflora coming from the intestines. In blood serum from v. cava and v. porta, urease activity (an indicator of bacterial contamination), lysozyme activity (nonspecific immunity factor) were determined in the liver, heart, brain, skeletal muscle and intestinal mucosa, and the degree of dysbiosis was calculated by the ratio of the relative activities of urease and lysozyme.Results. Blood urease activity v. porta was elevated in rats treated with HFD and was significantly higher than in blood v. cava. In most of the tissues studied, urease activity increased after HFD with the exception of rats treated with high oleic sunflower oil (HOSO), the development of dysbiosis in all tissues of the body. The exception is HOSO, which does not cause the development of dysbiosis and inflammation
Prevention of colitis in rats receiving palm oil on the background of dysbiosis by using quertulin
Aim: Identify the possibility of preventing colitis that develops in rats when consuming palm oil against dysbiosis.
Materials and Methods: Antidysbiosis agent "Quertulin" (Quercetin + Inulin + Citrate Ca) was used. Biological experiments were performed on rats receiving a non-fat diet (NFD). The second group of rats received a diet in which 15% of starch was replaced with 15% palm oil containing 42% palmitic acid (C16:0). The third group of rats received a diet of palm oil and, in addition, received quertulin 400 mg / kg daily for 38 days. Rats of the 2nd and 3rd groups for development of dysbiosis from the first day of the experiment received lincomycin (60 mg / kg) with drinking water for 5 days. The activity of elastase, catalase, urease, lysozyme and the content of malodialdehyde (MDA) was determined in the gut mucosal homogenates. The ratio of catalase and MDA was calculated by the antioxidant-prooxidant index of API, according to the ratio of relative activity of urease and lysozyme – the degree of dysbiosis.
Results: In rats receiving palm oil on the background of dysbiosis, the activity of elastase, urease, MDA content and the degree of dysbiosis increases in the mucosa of the colon, but the activity of catalase, lysozyme, and index API decreases. In rats receiving quertulin, the level of elastase, MDA, catalase, urease and lysozyme normalized, the API index increased and the degree of dysbiosis decreased.
Conclusions: Consumption of palm oil on the background of dysbiosis causes the development of colitis and dysbiosis by reducing the level of nonspecific immunity and antioxidant protection. Antidysbiotic mean Quertulin has mucosoprotective action
Experimental treatment of dysbiosis in colitis with hepatitis
Nonspecific colitis (inflammation of the colon mucosa) is a common gastroenterological disease. The causative factors of this disease are intestinal dysbiosis, which leads to an increase in blood concentration of intestinal endotoxin (lipopolysaccharide), as well as impaired liver antimicrobial function. The purpose of this study was to determine the possibility of preventing colitis, which develops as a result of a combination of dysbiosis and hepatitis, with the help of biotrit, which has an antidysbiotic and hepatoprotective effect. The experiments were conducted on 24 white rats of the Wistar line (males, 1 month old), divided into 3 equal groups: 1 - control (normal); 2 - dysbiosis + hepatitis without treatment; 3 - dysbiosis + hepatitis + drug "Biotrit". Dysbiosis was caused by the antibiotic lincomycin, which was given to rats with drinking water at a dose of 60 mg / kg for the first 5 days. Toxic hepatitis was reproduced in rats using hydrazine hydrochloride. Studies have shown that the phytopreparation Biotrit has a mucosoprotective effect in experimental nonspecific colitis due to both antidysbiotic and antioxidant effects
Motif models proposing independent and interdependent impacts of nucleotides are related to high and low affinity transcription factor binding sites in Arabidopsis
Position weight matrix (PWM) is the traditional motif model representing the transcription factor (TF) binding sites. It proposes that the positions contribute independently to TFs binding affinity, although this hypothesis does not fit the data perfectly. This explains why PWM hits are missing in a substantial fraction of ChIP-seq peaks. To study various modes of the direct binding of plant TFs, we compiled the benchmark collection of 111 ChIP-seq datasets for Arabidopsis thaliana, and applied the traditional PWM, and two alternative motif models BaMM and SiteGA, proposing the dependencies of the positions. The variation in the stringency of the recognition thresholds for the models proposed that the hits of PWM, BaMM, and SiteGA models are associated with the sites of high/medium, any, and low affinity, respectively. At the medium recognition threshold, about 60% of ChIP-seq peaks contain PWM hits consisting of conserved core consensuses, while BaMM and SiteGA provide hits for an additional 15% of peaks in which a weaker core consensus is compensated through intra-motif dependencies. The presence/absence of these dependencies in the motifs of alternative/traditional models was confirmed by the dependency logo DepLogo visualizing the position-wise partitioning of the alignments of predicted sites. We exemplify the detailed analysis of ChIP-seq profiles for plant TFs CCA1, MYC2, and SEP3. Gene ontology (GO) enrichment analysis revealed that among the three motif models, the SiteGA had the highest portions of genes with the significantly enriched GO terms among all predicted genes. We showed that both alternative motif models provide for traditional PWM greater extensions in predicted sites for TFs MYC2/SEP3 with condition/tissue specific functions, compared to those for TF CCA1 with housekeeping functions. Overall, the combined application of standard and alternative motif models is beneficial to detect various modes of the direct TF-DNA interactions in the maximal portion of ChIP-seq loci
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