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101.
Lioudyno MI Broccio M Sokolov Y Rasool S Wu J Alkire MT Liu V Kozak JA Dennison PR Glabe CG Lösche M Hall JE 《PloS one》2012,7(4):e35090
The impact of synthetic amyloid β (1-42) (Aβ(1-42)) oligomers on biophysical properties of voltage-gated potassium channels Kv 1.3 and lipid bilayer membranes (BLMs) was quantified for protocols using hexafluoroisopropanol (HFIP) or sodium hydroxide (NaOH) as solvents prior to initiating the oligomer formation. Regardless of the solvent used Aβ(1-42) samples contained oligomers that reacted with the conformation-specific antibodies A11 and OC and had similar size distributions as determined by dynamic light scattering. Patch-clamp recordings of the potassium currents showed that synthetic Aβ(1-42) oligomers accelerate the activation and inactivation kinetics of Kv 1.3 current with no significant effect on current amplitude. In contrast to oligomeric samples, freshly prepared, presumably monomeric, Aβ(1-42) solutions had no effect on Kv 1.3 channel properties. Aβ(1-42) oligomers had no effect on the steady-state current (at -80 mV) recorded from Kv 1.3-expressing cells but increased the conductance of artificial BLMs in a dose-dependent fashion. Formation of amyloid channels, however, was not observed due to conditions of the experiments. To exclude the effects of HFIP (used to dissolve lyophilized Aβ(1-42) peptide), and trifluoroacetic acid (TFA) (used during Aβ(1-42) synthesis), we determined concentrations of these fluorinated compounds in the stock Aβ(1-42) solutions by (19)F NMR. After extensive evaporation, the concentration of HFIP in the 100× stock Aβ(1-42) solutions was ~1.7 μM. The concentration of residual TFA in the 70× stock Aβ(1-42) solutions was ~20 μM. Even at the stock concentrations neither HFIP nor TFA alone had any effect on potassium currents or BLMs. The Aβ(1-42) oligomers prepared with HFIP as solvent, however, were more potent in the electrophysiological tests, suggesting that fluorinated compounds, such as HFIP or structurally-related inhalational anesthetics, may affect Aβ(1-42) aggregation and potentially enhance ability of oligomers to modulate voltage-gated ion channels and biological membrane properties. 相似文献
102.
103.
E. I. Sokolov V. A. Metelskaya L. A. Ratnikova O. I. Gorbacheva G. N. Shchukina I. E. Petrichenko V. M. Fomina N. V. Perova 《Human physiology》2004,30(6):695-698
The relationship between disturbances of hemostasis, blood insulin, and type of obesity was studied in nonobese subjects and in obese subjects with different body fat distribution under the conditions of postprandial lipemia (after a single standard fat load). In total, 44 subjects (16 men and 28 women aged 18–58) were divided into three groups according to the presence and type of obesity: a group with normal body weight, a group with abdominal obesity, and a group with gluteofemoral obesity. In abdominal obesity, triglyceride clearance was low and insulin secretion after a fat load was abnormally prolonged over 6 h; consequently, fibrinolysis decreased. Hemostasis disturbances in the obese subjects were aggravated by increased fibrinogen. Thus, a combination of metabolically associated disturbances (hypertriglyceridemia, hyperinsulinemia, and hypofibrinolysis) increases considerably the risk of coronary heart disease (CHD) in obese subjects, especially, in those with abdominal obesity. 相似文献
104.
Alternaria alternata is a common fungal parasite on fruits and other plants and produces a number of mycotoxins, including alternariol (3,7,9-trihydroxy-1-methyl-6H-dibenzo [b,d]pyran-6-one), alternariol monomethyl ether (3,7-dihydroxy-9-methoxy-1-methyl-6H-dibenzo[b,d]pyran-6-one), and the mutagen altertoxin I {[1S-(1α,12aβ,12bα)] 1,2,11,12,12a, 12b-hexahydro-1,4,9,12a-tetrahydroxy-3,10-perylenedione}.
Alternariol and alternariol monomethyl ether have previously been detected in some samples of fruit beverages. Stability studies
of these toxins as well as altertoxin I added to fruit juices and wine (10–100 ng/mL) were carried out. To include altertoxin
I in the analysis, cleanup with a polymer-based Varian Abselut solid phase extraction column was used, as recoveries from
C-18 columns were low. The stabilities of alternariol and alternariol monomethyl ether in a low acid apple juice containing
no declared vitamin C were compared with those in the same juice containing added vitamin C (60 mg/175 ml); there were no
apparent losses at room temperature over 20 days or at 80°C after 20 min. in either juice. Altertoxin I was moderately stable
in pH 3 buffer (75% remaining after a two week period). Furthermore, altertoxin I was stable or moderately stable in three
brands of apple juice tested over 1–27 day periods and in a sample of red grape juice over 7 days. It is concluded that altertoxin
I is sufficiently stable to be found in fruit juices and should be included in methods for alternariol and alternariol monomethyl
ether. 相似文献
105.
Seven polymorphic microsatellite loci are described in the marine intertidal gastropod Littorina saxatilis. Preliminary data on allelic variation of these loci in a White Sea population of L. saxatilis are presented in order to assess their potential utility as high‐resolution genetic markers for this model species. 相似文献
106.
Vinarov A. Yu. Robysheva Z. N. Smirnov V. N. Sokolov D. P. 《Applied Biochemistry and Microbiology》2002,38(5):445-449
Results of industrial exploitation of a biofiltration plant tailored for purifying gaseous discharges of hazardous organic components such as toluene, cyclohexane, and xylene, are examined. Both numerical and compositional variations were monitored for a long-term (more than 1.5 years) utilization process in an association of microorganisms decomposing organic pollutants. A population of microbial association composed by one yeast and two bacterial strains in the biofilm on the surface of filtering sheets was abundant (108–109 yeast cells/cm2 and 1010–1011 bacterial cells/cm2) and stable during the whole period of monitoring. A microbial association in the culture medium averaging 106 yeast cells/l and 108 bacterial cells/l is more susceptible to technogenic impacts and seasonal fluctuations. Overall, the biofilter as an open and autonomic system maintained its microbial association, thereby providing high-degree (93–98%) purification of industrial gaseous discharges from organic pollutants. 相似文献
107.
The content of total protein, glycoproteins, and N-acetylneuraminic acid in different membrane fractions of rat brain tissues was studied 60 min and 24 h following X-irradiation with a dose of 0.31 C/kg. A slight increase in the amount of glycoproteins was noted upon electrophoresis due to the occurrence of low molecular weight carbohydrate-containing proteins. The derangement of the membrane glycoprotein structure is supposed to be one on the causes of radiation destruction of membranes. 相似文献
108.
The influence of X-radiation on activity of lysosomal enzymes (D, L, H cathepsins) in rat spleen tissue and in inoculated rat sarcoma 45 has been investigated. Intact rats and rats with tumors were subjected to whole-body and sarcoma 45 to local irradiation with doses of 0.155 C/kg and 0.31 C/kg in conditions of breathing gas hypoxic mixture containing 90% of nitrogen and 10% of oxygen (GHM-10). The combined exposure to radiation and GHM-10 was shown to produce a certain protective action (e.g. normalized cathepsin activity) in the spleen. In the tumor tissue the protective effect of GHM-10 was absent. 相似文献
109.
O B Sokolov N N Blinov I N Zaltsman N I Rozhkova V N Zubritski? 《Vestnik rentgenologii i radiologii》1991,(1):50-53
A device and the results of a 3-year performance of cellular grids for mammography were described. An increase in the informative value and a decrease in radiation exposure of patients were shown during mammography with a cellular grid. 相似文献
110.
A V Latanov V B Polianski? E N Sokolov 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》1991,41(4):636-646
Discrimination of colours by macaque rhesus was studied by the method of elaboration of differentiation inhibition of instrumental conditioned responses to colour stimuli. Matrix of probabilities of instrumental reactions to presentation of colour stimuli, the columns of which corresponded to the colours applied, and the lines--to series of experiments with definite reinforced colour--was processed by the method of factor analysis. Four factors describing the used colours in four-dimensional Euclidean space were singled out. Spatial structure of the seven used colours satisfies the equation of four-dimensional sphere. Two first factors are interpreted as colour-opponent red-green and yellow-blue and the third and fourth ones as achromatic light and dark neuronal channels. Perceptive space of colour stimuli based on the data of instrumental behaviour of the monkey corresponds to analogous results obtained by the method of multidimensional scaling of subjective evaluations of super-threshold colour differences for the man. 相似文献