The Experts below are selected from a list of 72 Experts worldwide ranked by ideXlab platform
I Iu Borshchëva - One of the best experts on this subject based on the ideXlab platform.
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Responses of Peptide Hydrolases of the small and large intestines in rats on the administration of antibiotics
Rossiiskii fiziologicheskii zhurnal imeni I.M. Sechenova, 2012Co-Authors: Iu Iu Borshchëv, E I Ermolenko, I Iu BorshchëvaAbstract:Effects of antibiotics on the structure and functional state of the intestine are not clear. We investigated some structural parameters of the small and large intestine, and activities of two intestinal Peptide Hydrolases in rats after administration of ampicillin and metronidazole during 3 and 5 days. After 3 days of antibiotic administration a decrease in the weight of mucosa in the small intestine, accompanied with a reduction in the villous height and width in this part of the intestine, and in the weight ofmucosa in the colon occured. At the same time the number of goblet cells in the small intestinal epithelium was increased. Specific activities of aminopeptidase M, and glycyl-L-leucine dipeptidase (micromol/min per g) in the mucosa of the small intestine were increased, and the total activities (micromol/min calculated per a part of the intestine) of the same enzymes did not change. The administration of antibiotics for 5 days resulted in increase of specific activity ofaminopeptidase M in the mucosa of the proximal part of the small intestine. In the chyme of the small intestine and colon, activities of the same enzymes (micromol/min calculated per a part of the intestine) were increased on the third and fifth days of the antibiotic administration. Thus, the application ofampicillin and metronidazole within 3-5 days causes a disturbance of the structural and functional parameters in the small and large intestines, which is most pronounced on the third day of the drug administration.
N. M. Timofeeva - One of the best experts on this subject based on the ideXlab platform.
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Activity of Peptide Hydrolases in Epithelial and Subepithelial Layers of Small Intestine of Rats of Different Age after Protein Deprivation
Journal of Evolutionary Biochemistry and Physiology, 2002Co-Authors: Yu. V. Nevmyvak, N. M. TimofeevaAbstract:A significant decrease of protein content in epithelial, stromal, and muscular-serosal layers of jejunum and ileum, especially in aged animals, is revealed in rats of different age groups (young, mature, aged) after 10-day-long protein deprivation. The responses of Peptide Hydrolases (aminopeptidase M and glycylleucine dipeptidase) were different. There were, as a rule, no changes of these enzyme activities in small intestine of young rats, except for decreased activity of aminopeptidase M in stromal layer of jejunum and increased activity of both Peptide Hydrolases in epithelial layer of ileum. In mature animals, increased activities of these enzymes also was observed in the epithelial layer of jejunum and ileum and in the stromal layer of ileum in comparison with the rats receiving a full-value nutrition. In aged rats, a much more pronounced rise of these enzyme activities in the layers of small intestine was revealed after protein starvation in comparison with young and mature rats. Probably, such increase of the Peptide hydrolase activities in the layers of small intestine after protein deprivation can be considered as an adaptive-protective reaction of the organism in response to formation of significant amounts of low-molecular Peptides as a result of protein catabolism
Iu Iu Borshchëv - One of the best experts on this subject based on the ideXlab platform.
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Responses of Peptide Hydrolases of the small and large intestines in rats on the administration of antibiotics
Rossiiskii fiziologicheskii zhurnal imeni I.M. Sechenova, 2012Co-Authors: Iu Iu Borshchëv, E I Ermolenko, I Iu BorshchëvaAbstract:Effects of antibiotics on the structure and functional state of the intestine are not clear. We investigated some structural parameters of the small and large intestine, and activities of two intestinal Peptide Hydrolases in rats after administration of ampicillin and metronidazole during 3 and 5 days. After 3 days of antibiotic administration a decrease in the weight of mucosa in the small intestine, accompanied with a reduction in the villous height and width in this part of the intestine, and in the weight ofmucosa in the colon occured. At the same time the number of goblet cells in the small intestinal epithelium was increased. Specific activities of aminopeptidase M, and glycyl-L-leucine dipeptidase (micromol/min per g) in the mucosa of the small intestine were increased, and the total activities (micromol/min calculated per a part of the intestine) of the same enzymes did not change. The administration of antibiotics for 5 days resulted in increase of specific activity ofaminopeptidase M in the mucosa of the proximal part of the small intestine. In the chyme of the small intestine and colon, activities of the same enzymes (micromol/min calculated per a part of the intestine) were increased on the third and fifth days of the antibiotic administration. Thus, the application ofampicillin and metronidazole within 3-5 days causes a disturbance of the structural and functional parameters in the small and large intestines, which is most pronounced on the third day of the drug administration.
Christian Ihling - One of the best experts on this subject based on the ideXlab platform.
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expression of macrophage migration inhibitory factor in different stages of human atherosclerosis
Circulation, 2002Co-Authors: Anke Burgerkentischer, Heike Goebel, Rudiger Seiler, Gustav Fraedrich, Hans E Schaefer, Stefanie Dimmeler, Robert Kleemann, Jurgen Bernhagen, Christian IhlingAbstract:Background - Atherosclerosis is a chronic inflammatory response of the arterial wall to injury. Macrophage migration inhibitory factor (MIF), a cytokine with potent inflammatory functions, was thus considered to be important in atherosclerotic lesion evolution. Methods and Results - We studied the presence and distribution of MIF immunoreactivity (MIF-IR) and MIF mRNA in internal mammary arteries with a normal histology and arteries with plaques in different stages of human atherosclerosis. To address a potential role for the coactivator Jab1 as a cellular mediator of MIF effects in vascular tissue, we correlated the expression of MIF to that of Jab1 by using immunohistochemistry and coimmunoprecipitation. We further sought to determine a potential functional role for endothelium-derived MIF in early atherogenesis by studying the effects of oxidized LDL on MIF expression in cultured human umbilical vascular endothelial cells. The results showed that MIF-IR and Jab1-IR are found in all cell types present in atherosclerotic lesions, that MIF-IR is upregulated during progression of atherosclerosis, that MIF is produced locally in the arterial wall, and that all MIF+ cells are simultaneously Jab1 +. Coimmunoprecipitation experiments demonstrated in vivo complex formation between MIF and Jab1 in plaques. MIF expression in human umbilical vascular endothelial cells and a macrophage line was upregulated after stimulation with oxidized LDL. Conclusions - MIF is produced abundantly by various cells in all types of human atherosclerotic lesions and thus may play an important role in early plaque development and advanced complicated lesions. MIF-Jab1 complexes could serve critical regulatory functions in atherosclerotic lesion evolution. Chemicals/CAS: COPS5 protein, human, EC 3.4.-.-; DNA-Binding Proteins; Intracellular Signaling Peptides and Proteins; Lipoproteins, LDL; Macrophage Migration-Inhibitory Factors; oxidized low density lipoprotein; Peptide Hydrolases, EC 3.4.-; Transcription Factors
Fassil Assefa - One of the best experts on this subject based on the ideXlab platform.
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The Role of Microbial Aspartic Protease Enzyme in Food and Beverage Industries
Journal of Food Quality, 2018Co-Authors: Jermen Mamo, Fassil AssefaAbstract:Proteases represent one of the three largest groups of industrial enzymes and account for about 60% of the total global enzymes sale. According to the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology, proteases are classified in enzymes of class 3, the Hydrolases, and the subclass 3.4, the Peptide Hydrolases or peptidase. Proteases are generally grouped into two main classes based on their site of action, that is, exopeptidases and endopeptidases. Protease has also been grouped into four classes based on their catalytic action: aspartic, cysteine, metallo, and serine proteases. However, lately, three new systems have been defined: the threonine-based proteasome system, the glutamate-glutamine system of eqolisin, and the serine-glutamate-aspartate system of sedolisin. Aspartic proteases (EC 3.4.23) are peptidases that display various activities and specificities. It has two aspartic acid residues (Asp32 and Asp215) within their active site which are useful for their catalytic activity. Most of the aspartic proteases display best enzyme activity at low pH (pH 3 to 4) and have isoelectric points in the pH range of 3 to 4.5. They are inhibited by pepstatin. The failure of the plant and animal proteases to meet the present global enzyme demand has directed to an increasing interest in microbial proteases. Microbial proteases are preferred over plant protease because they have most of the characteristics required for their biotechnological applications. Aspartic proteases are found in molds and yeasts but rarely in bacteria. Aspartic protease enzymes from microbial sources are mainly categorized into two groups: (i) the pepsin-like enzymes produced by Aspergillus, Penicillium, Rhizopus, and Neurospora and (ii) the rennin-like enzymes produced by Endothia and Mucor spp., such as Mucor miehei, M. pusillus, and Endothia parasitica. Aspartic proteases of microbial origin have a wide range of application in food and beverage industries. These include as milk-clotting enzyme for cheese manufacturing, degradation of protein turbidity complex in fruit juices and alcoholic liquors, and modifying wheat gluten in bread by proteolysis.