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241.
The enzyme activity of Mg-ATPase, Na+ -K+ -ATPase, 5'-nucleotidase and NAD(P)H-oxidase was cytochemically detected at the ultrastructural level in mouse peritoneal macrophages infected with untreated and with specific antibody-coated Toxoplasma gondii tachyzoites. The Mg++ -ATPase and 5'-nucleotidase were distributed throughout the macrophages'plasma membrane but were not observed in the membrane lining endocytic vacuoles containing ingested parasites; however, Na+ -K+ -ATPase activity was detected in the macrophages'plasma membrane as well as in the parasitophorous vacuoles that contained untreated or specific antibody-coated parasites. Reaction product, indicative of NAD(P)H-oxidase, was detected in the parasitophorous vacuoles that contained only-specific antibody-coated parasites. 相似文献
242.
Gorbacheva LR Storozhevykh TP Pinelis VG Davydova ON Ishiwata S Strukova SM 《Biochemistry. Biokhimii?a》2008,73(6):717-724
The effect of an anticoagulant and cytoprotector blood serine proteinase--activated protein C (APC)--on survival of cultured hippocampal and cortical neurons under conditions of glutamate-induced excitotoxicity has been studied. Low concentrations of APC (0.01-10 nM) did not cause neuron death, but in the narrow range of low concentrations APC twofold and stronger decreased cell death caused by glutamate toxicity. High concentrations of APC (>50 nM) induced the death of hippocampal neurons similarly to the toxic action of glutamate. The neuroprotective effect of APC on the neurons was mediated by type 1 proteinase-activated receptor (PAR1), because the inactivation of the enzyme with phenylmethylsulfonyl fluoride or PAR1 blockade by a PAR1 peptide antagonist ((Tyr1)-TRAP-7) prevented the protective effect of APC. Moreover, APC inhibited the proapoptotic effect of 10 nM thrombin on the neurons. Geldanamycin, a specific inhibitor of heat shock protein Hsp90, completely abolished the antiapoptotic effect of 0.1 nM APC on glutamate-induced cytotoxicity in the hippocampal neurons. Thus, APC at low concentrations, activating PAR1, prevents the death of hippocampal and cortical neurons under conditions of glutamate excitotoxicity. 相似文献
243.
Veena?DhawanEmail author SS?Handu Chandra?Kanwal?Nain Nirmal?Kumar?Ganguly 《Molecular and cellular biochemistry》2005,269(1):1-11
Chronic exposure to l-arginine results in regression of atherosclerotic lesions and reversal of endothelial dysfunction. We investigated whether chronic l-arginine supplementation induces regression of atherosclerotic lesions and reversal of endothelial dysfunction in atherogenic rhesus monkeys and the mechanism which leads to these effects. About 12 male rhesus monkeys were fed 1% cholesterol and 18 g butter for 6 months to create an experimental model of hypercholesterolaemia and atherosclerosis (Group I) and 12 monkeys were fed standard stock diet for 6 months (Group II). After, 6 months these two groups were further divided into 2 sub-groups which in addition to their respective diets were fed 2.5% l-arginine in drinking water for additional 6 months (Group III and Group IV). Systemic nitric oxide (NO) formation was assessed as plasma nitrite and cGMP formation every 3 months. Oxygen free radical (OFR) generation and malondialdehyde production as an index of lipid peroxidation were determined. Changes in isometric tension were compared in isolated ring segments of thoracic aorta from normal and hypercholesterolemic animals.Cholesterol feeding progressively reduced plasma nitrite and cGMP generation (p<0.05). Dietary l-arginine partly restored the levels of plasma nitrite and cGMP (p<0.05) but did not change plasma cholesterol levels. l-arginine significantly reduced aortic intimal thickening, blocked the production of carotid and coronary intimal plaques and completely preserved endothelium-dependent vasodilator function. Further, l-arginine significantly inhibited generation of the reactive oxygen species (ROS) generation and lipid peroxidation.Chronic oral supplementation with l-arginine blocks the progression of plaques via restoration of nitric oxide synthase substrate availability and reduction of vascular oxidative stress. (Mol Cell Biochem 269: 1–11, 2005) 相似文献
244.
Shkarin VV Davydova NA Kolmakova NA 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》2002,(4):98-102
The work deals with the tendency of introducing superfluous terms in epidemiology and other medical sciences. Four groups of foreign terminology, occurring in scientific literature on different problems of epidemiology, are presented. Examples of publications containing terms and notions whose interpretation is absent in dictionaries are given. 相似文献
245.
The physicochemical properties of chitosan samples with high (130 kD) and low (30 kD) molecular masses in neutral aqueous solutions (pH 6.0) were studied by the methods of high-speed and equilibrium sedimentation, viscosimetry, and NMR and UV spectroscopies. Differences in the hydrodynamic characteristics of the samples were revealed. It was found that low-molecular-weight chitosan represents flexible linear macromolecules which undergo conformational changes upon temperature increase. The high-molecular-weight chitosan forms more rigid asymmetric structures whose conformation does not vary significantly with temperature increase. It was found that the high-molecular-weight chitosan has a higher constant of binding to the anionic dye tropeoline 000-II, which can be explained by different conformations of their macromolecules in solution. 相似文献
246.
Flekhter OB Karachurina LT Poroĭkov VV Nigmatullina LR Baltina LA Zarudiĭ FS Davydova VA Spirikhin LV Baĭkova IP Galin FZ Tolstikov GA 《Bioorganicheskaia khimiia》2000,26(3):215-223
Hemisuccinates, hemiphthalates, acetylsalicylates, cinnamates, and p-methoxycinnamates of lupeol, betulin, and 3-O-acetylbetulin were synthesized via interaction with corresponding acid anhydrides or acid chlorides. A number of betulin esters in position 3 and 28 were shown to exhibit a pronounced hepatoprotective effect similar to that of betulin and silibor. These experimental data were in a good agreement with the computer prediction of their biological activity. Betulin 3,28-bis-hemiphthalate was more effective than carsil in models of experimental hepatitis caused by carbon tetrachloride, tetracycline, and ethanol. 相似文献
247.
Skarin VV Davydova NA Kovalishena OV 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》2000,(6):30-34
The main principles of prospective observation in cardiosurgical hospitals have been worked out. The method of dynamic observation on hospital pyo-septic infections (HPSI) has shown its high effectiveness and permitted the more complete and timely detection of morbidity, as well as the determination of the groups and factors of risk. In the process of prospective observation and the timely realization of epidemic control measures a considerable decrease in HPSI morbidity has been achieved. 相似文献
248.
Davydova N Streltsov VA Roufail S Lovrecz GO Stacker SA Adams TE Achen MG 《Protein expression and purification》2012,82(1):232-239
Vascular endothelial growth factor-D (VEGF-D), a secreted angiogenic and lymphangiogenic glycoprotein, enhances tumor growth and metastasis in animal models, and its expression correlates with metastasis and poor patient outcome in some cancers - it is therefore considered a target for novel anti-cancer therapeutics. The definition of the structure of the complex of VEGF-D bound to its receptors would be beneficial for design of inhibitors of VEGF-D signaling aimed at restricting the growth and spread of cancer. In addition, there is interest in using VEGF-D protein for therapeutic angiogenesis and lymphangiogenesis in the settings of cardiovascular diseases and lymphedema, respectively. However, VEGF-D has proven difficult to express and purify in a highly bioactive form due to a tendency to exist as monomers rather than bioactive dimers. Here we describe a protocol for expression and purification of mature human VEGF-D, and a mutant thereof with reduced glycosylation, potentially suitable for preclinical therapeutic and structural studies, respectively. The degree of glycosylation in mature VEGF-D was reduced by eliminating one of the two N-glycosylation sites, and expressing the protein in Lec3.2.8.1 cells which had reduced glycosylation capacity. Mature VEGF-D and the glycosylation mutant were each enriched for the biologically active dimeric form by optimizing the separation of dimer from monomer via gel filtration, followed by conversion of remaining monomers to dimers via treatment with cysteine. The glycosylation mutant of VEGF-D intended for structural studies preserved all the cysteine residues of mature VEGF-D, in contrast to previous structural studies, exhibited comparable receptor binding to mature VEGF-D and might facilitate structural studies of the VEGF-D/VEGFR-3 complex. 相似文献
249.
D.?G.?DeryabinEmail author O.?K.?Davydova I.?V.?Gryazeva G.?I.?El’-Registan 《Microbiology》2012,81(2):168-177
This work is concerned with the role of alkylhydroxybenzenes (AHBs), chemical analogs of the autoregulatory microbial d
1 factors, on the development of the stress response of bacterial cells to UV irradiation, including SOS system induction,
preservation of cell viability, and S → R phase transitions of the Escherichia coli test strain with the bioluminescence genes cloned under the control of the recA gene promoter. UV irradiation, a natural stress factor, and an increase in AHB concentrations were found to elicit uniform
responses in bacteria, indicating that AHBs function as alarmones, i.e., alarm signals. It was revealed that preincubating
bacteria with alkylhydroxybenzenes considerably enhanced their viability upon irradiation with lethal UV doses; this was accompanied
by a relative decrease in the SOS response activity and a concomitant increase in the frequency of phase transitions. The
efficiency of the protective action of AHBs increased with an increase in their hydrophobicity degree. The probable mechanism
of the protective effect of AHBs is discussed, based on their capacity for the interaction with biopolymers, which results
in changing their structural organization and conferring resistance to a broad spectrum of stress factors. Such a “passive”
protective mechanism reduces the susceptibility of DNA to UV irradiation, causing a decrease in the parameters related to
the SOS system induction that is responsible for the “active” protective mechanism in bacterial cells. As a result, viability
retention under the lethal influence of UV irradiation is possible at minimal values of repair activity and is accompanied
by an increase in the phenotypic variability of the surviving part of a bacterial population. 相似文献
250.
Malykh S. B. Malykh A. S. Karunas A. S. Enikeeva R. F. Davydova Y. D. Khusnutdinova E. K. 《Russian Journal of Genetics》2019,55(7):783-793
Russian Journal of Genetics - The paper presents a review of the results of molecular genetic studies of cognitive abilities. To date, a small number of genes responsible for normal cognitive... 相似文献