排序方式: 共有56条查询结果,搜索用时 0 毫秒
1.
A. V. Dyatlov 《Neurophysiology》1993,25(1):26-32
The effects of Ca2+ and vitamin E (-tocopherol) on acetylcholine (Ach)-induced Cl– currents in LP11 and RBc4 neurons of the snail Helix pomatia have been studied. Injection of Ca2+ into the cells and application of vitamin E (10–5 mole/liter) induced the appearance of potentiation of Ach-induced currents in membrane parts more remote from the axon than the Ach-sensitive regions in the control. The Hill coefficient (n) for such Ach receptors was equal to 0.8, unlike 1.8 for Ach receptors active in the control. Arachidonic acid (10–5 mole/liter) and phorbol ester TPA (10–6 mole/liter) inhibited Ach responses, while oleoylacetyglycerol (10–6 mole/liter) produced no effect. Calmidazolium (10–6 mole/liter) decreased the effects of Ca2+ and vitamin E on Ach responses, while nordihydroquiaretic acid (5 · 10–6 mole/liter) enhanced the modulating effect of vitamin E and weakened that of arachidonic acid. It is suggested that the expression of Ach receptors activated by Ca2+ and vitamin E is mediated through posttranslational mechanisms, since cycloheximide and actinomycin D, inhibitors of protein synthesis, did not influence the effects of C2+ and vitamin E. The mechanisms responsible for the stimulating effects of Ca2+ and vitamin E are discussed.Translated from Neirofiziologiya, Vol. 25, No. 1, pp. 31–39, January–February, 1993. 相似文献
2.
3.
V. A. Dyatlov 《Neurophysiology》1992,24(2):100-107
The chemical nature of the carbohydrate determinants of the plasma membrane that affect the responses of identified neurons of the molluskHelix pomatia, induced by application of acetylcholine (ACh), was studied using D-mannose-specific (ConA), D-galactose-specific (RCA), N-acetyl-D-glucosamino-specific (WGA), and sialo-specific (LPA) lectins. Differences in the change in the Ach-induced chloride and sodium-potassium currents under the action of ConA and in the time and temperature dependences of the effects of ConA for these currents are evidence of the presence of different mechanisms of the influence of carbohydrate determinants containing mannose residues on the functional properties of the cholinergic receptors. On the basis of the time and temperature dependences of the inhibiting effects of WGA and RCA on the ACh-induced currents, it was suggested that endocytosis of the lectin-receptor complexes containing N-acetyl-D-glucosamine residues occurs.A. A. Bogomolets Institute of Physiology, Ukrainian Academy of Sciences, Kiev. Translated from Neirofiziologiya, Vol. 24, No. 2, pp. 161–169, March–April, 1992. 相似文献
4.
The effect of lincocin (a plastid protein synthesis inhibitor) treatment on the greening process of bean (Phaseolus vulgaris L.) leaves have been studied. In comparison with control leaves treated ones had a decreased rate of chloroplast development. They had a marked chlorophyll deficiency and a decreased chlorophyll a/b ratio. Some long and short wavelength forms of chlorophyll a were lacking as evidenced from the absorption spectra at 25°C and the fluorescence spectra at 77°K. The –14CO2 fixation was inhibited by 80–90% in treated leaves. The fluorescence induced by the measuring light was greater in the treated leaves than in the control ones, and the kinetics of the decline of the relative fluorescence intensity were also different. Electron microscopic studies showed macrogranum-like structures and incomplete membrane vesicles in the treated plastids. After longer treatment a destruction of membranes was observed. The results indicate some structural and functional membrane deficiencies and instability of the membranes. 相似文献
5.
6.
Levashov PA Popov DV Popova VM Zhilenkov EL Morozova OA Belogurova NG Sedov SA Dyatlov IA Klyachko NL Levashov AV 《Biochemistry. Biokhimii?a》2010,75(9):1160-1164
Bacteriophage enzyme preparations exolysin and endolysin were studied. Exolysin (a phage-associated enzyme) was obtained from
tail fraction and endolysin from phage-free cytoplasmic fraction of disintegrated Salmonella enteritidis cells. A new method for purification of these enzymes was developed, and their molecular masses were determined. The main
catalytic properties of the studied enzymes (pH optimum and specificity to bacterial substrates) were found to be similar.
Both enzymes lyse Escherichia coli cells like chicken egg lysozyme, but more efficiently lyse S. enteritidis cells and cannot lyse Micrococcus luteus, a good substrate for chicken egg lysozyme. Similar properties of exolysin and endolysin suggest that these enzymes are structurally
similar or even identical. 相似文献
7.
A. E. Khlyntseva E. V. Belova I. V. Zharnikova I. S. Tyumentseva A. N. Kulichenko I. A. Dyatlov I. G. Shemyakin 《Applied Biochemistry and Microbiology》2011,47(7):700-706
Magnetic immunosorbents (MIS) have been designed using antianthrax monoclonal antibodies immobilized on aluminum silicate—iron
oxide matrix activated by sodium perchlorate. MIS allows us to concentrate the analyzed microorganism and to decontaminate
culture from concomitant microflora. Diagnostic test systems constructed on the basis of MIS were tested on pure Bacillus anthracis cultures and in the model experiments. The results testify to the high specificity and sensitivity (102–103 spore/ml) of the designed test systems. 相似文献
8.
Bacillus cereus sensu lato group, which includes the causative agent of anthrax Bacillus anthracis, has a high degree of genetic similarity. However, in recent years, the development of molecular genetics has made it possible to find some molecular markers for identifying Bacillus anthracis in order to differentiate it from the closely related bacilli, get the clustering of the collection of strains, and describe the phylogenetic relationships between the clusters. This article deals with up-to-date methods of genotyping of Bacillus anthracis; it also evaluates its discrimination ability, informational value, validity of the results, efficiency, simplicity, and ease of use. In addition, international online resources and the possibility of their use for comparing collections of the B. anthracis strains isolated from various parts of the world are discussed. 相似文献
9.
10.
DIDIER FOURGON IGOR EECKHAUT DEVARAJEN VAÏTILINGON MICHEL JANGOUX 《Invertebrate reproduction & development.》2013,57(3):155-165
Summary The larval development of the ophiocomid ophiuroid Ophiomastix venosais described using SEM. The gastrula transforms into a uniformly ciliated early larva which progressively changes into a lecithotrophic late premetamorphic larva with a continuous bilateral ciliated band. This stage is short-lived and equivalent to a highly reduced ophiopluteus. Comparisons between O. venosa and other ophiuroid species whose development has been investigated suggest that, whatever the developmental mode (lecithotrophic or planktotrophic), a pluteus stage always occurs in ophiuroids with planktonic development. Two metamorphic stages were identified, the late metamorphic larva differing from the early one by the closure of the larval mouth. The appearance of the permanent mouth marks the end of the metamorphosis. The postlarva still possesses remnants of larval features. The transformation of the reduced ophiopluteus into a barrel-shaped metamorphic larva with transverse ciliated bands, a vitellaria larva, is followed. The possible occurrence of a unique type of metamorphic larva in non-brooding ophiuroids is discussed. Verification of this, however, needs further SEM investigations on metamorphic larva from species having “regular” planktotrophic development. 相似文献