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181.
O. L. Nesterova 《Entomological Review》2006,86(3):369-372
The last instar larva and pupa of Parnops glasunovi Jcbs. are described for the first time. A key to genera of the subfamily Eumolpinae from Middle Asia is given. 相似文献
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184.
L. A. Nesterova B. N. Manukhin 《Biochemistry (Moscow) Supplemental Series A: Membrane and Cell Biology》2013,7(4):280-285
The influence of activation and inhibition of serotonin receptors by serotonin (5HT) and miancerin on binding of specific nonselective α2-antagonist [3H]RX821002 in rat cerebral cortex membranes was studied. It was shown that the ligand-receptor interaction for α2-adrenoceptors corresponded to the model suggesting the presence of one pool of receptors and binding of two ligand molecules to the receptor. The parameters of the [3H]RX821002 binding to α2-adrenoceptors were as follows: K d = 1.57 ± 0.276 nM, B max = 7.24 ± 1.63 fmol/mg protein, n = 2. In the case of activation of 5HT-receptors by serotonin, the character of ligand binding was different: two pools of receptors were detected with the parameters K d1 = 0.82 ± 0.06; K d2 = 2.65 ± 0.22 nM; B m1 = 1.65 ± 0.23; B m2 = 4.20 ± 0.11 fmol/mg protein; n = 2. The affinity of high-affinity receptors increased twofold and the affininty of low-affinity receptors decreased by 69% as compared to control values. The concentration of high-affinity receptors decreased 4.4-fold, and of low-affinity, 1.7-fold. The value of maximal reaction (B max) decreased by 20%. In the case of miancerin-induced inhibition of 5HT-receptors the character of ligand binding also changed; two pools of receptors were detected with the following parameters: K d1 = 0.48 ± 0.09; K d2 = 3.79 ± 0.71 nM; B 1 = 0.63 ± 0.17; B 2 = 4.75 ± 0.21 fmol/mg protein; n = 2. The affinity of high-affinity receptors pool increased by 70% and that of low-affinity receptors decreased by 76% as compared to control values. The concentration of active high-affinity and low-affinity α2-adrenoceptors decreased by 70% and 141%, respectively. The total amount of the receptors (B max) decreased by 26%. The data suggest that α2-adrenoceptors in rat cerebral cortex exist as dimers. Modulatory effects of serotonin and miancerin on specific antagonist binding to α2-adrenoceptors may be accomplished by altering the character and binding parameters of the nonselective α2-antagonist [3H]RX821002. 相似文献
185.
Lysine is catabolized via the saccharopine pathway in plants and mammals. In this pathway, lysine is converted to α-aminoadipic-δ-semialdehyde (AASA) by lysine-ketoglutarate reductase/saccharopine dehydrogenase (LKR/SDH); thereafter, AASA is converted to aminoadipic acid (AAA) by α-aminoadipic-δ-semialdehyde dehydrogenase (AASADH). Here, we investigate the occurrence, genomic organization and functional role of lysine catabolic pathways among prokaryotes. Surprisingly, only 27 species of the 1478 analyzed contain the lkr and sdh genes, whereas 323 species contain aasadh orthologs. A sdh-related gene, identified in 159 organisms, was frequently found contiguously to an aasadh gene. This gene, annotated as lysine dehydrogenase (lysdh), encodes LYSDH an enzyme that directly converts lysine to AASA. Pipecolate oxidase (PIPOX) and lysine-6-aminotransferase (LAT), that converts lysine to AASA, were also found associated with aasadh. Interestingly, many lysdh–aasadh–containing organisms live under hyperosmotic stress. To test the role of the lysine-to-AASA pathways in the bacterial stress response, we subjected Silicibacter pomeroyi to salt stress. All but lkr, sdh, lysdh and aasadh were upregulated under salt stress conditions. In addition, lysine-supplemented culture medium increased the growth rate of S. pomeroyi under high-salt conditions and induced high-level expression of the lysdh–aasadh operon. Finally, transformation of Escherichia coli with the S. pomeroyi lysdh–aasadh operon resulted in increased salt tolerance. The transformed E. coli accumulated high levels of the compatible solute pipecolate, which may account for the salt resistance. These findings suggest that the lysine-to-AASA pathways identified in this work may have a broad evolutionary importance in osmotic stress resistance. 相似文献
186.
Natalia Bobkova Irina Guzhova Boris Margulis Inna Nesterova Natalia Medvedinskaya Alexander Samokhin Irina Alexandrova David Garbuz Evgeny Nudler Michael Evgen’ev 《Cell stress & chaperones》2013,18(1):109-118
Numerous epidemiological studies have established acute brain injury as one of the major risk factors for the Alzheimer''s disease (AD). However, the lack of animal models of AD-like degeneration triggered by a defined injury hampered the development of adequate therapies. Here we report that the surgical damage of the olfactory bulbs triggers the development of several pathologies, including amyloid-β accumulation and strong decrease of neuron density in the cortex and hippocampus as well as significant disturbance of spatial memory. Characteristically, these harmful consequences of the olfactory bulbectomy (OBX) have a peculiar dynamics in time with maximal manifestation in periods of 1–1.5 months and 8 months after the surgery and, hence, exhibit biphasic pattern with almost complete recovery period taking place at 5–6 months after the operation. The quantitative determination of endogenous inducible form of Hsp70 in different brain areas of OBX mice demonstrated characteristic fluctuations of Hsp70 levels depending on the time after the operation and age of mice. Interestingly, maximal induction of Hsp70 synthesis in the hippocampus exhibits clear-cut coincidence with the recovery period in OBX animals. The observed correlation enables to suggest curing effect of Hsp70 synthesis at an earlier period of pathology development and establishes it as a possible therapeutic agent for secondary grave consequences of brain injury, such as AD-like degeneration, for which neuroprotective therapy is urgently needed. 相似文献
187.
Phylogenetic analysis of slippage-like sequence variation in the V4 rRNA expansion segment in tiger beetles (Cicindelidae) 总被引:1,自引:1,他引:0
Sequence variation in the middle part of the small-subunit rRNA was studied
for representatives of the major groups in the family Cicindelidae
(Coleoptera). All taxa exhibited a much expanded segment in variable region
V4 compared to D. melanogaster. This expanded segment was not found in
other groups of beetles, including three taxa in the closely related
Carabidae. Secondary structure predictions indicate that the expanded
segment folds into a single stem-loop structure in all taxa. Despite its
structural conservation, the fragment differs strongly in primary sequence,
even between closely related sister taxa. Several features of these
sequences are consistent with slippage replication as the mechanism that
has generated this sequence variation: the level of internal sequence
repetition as measured by the relative simplicity factor (RSF), its
variation in length between close relatives, and the strong nucleotide bias
compared to the remainder of the gene. With few exceptions, there was also
a correlation between sequence length and the level of sequence repetition,
frequently interpreted as the result of slippage. Phylogenies inferred from
the expansion segment were not consistent with existing hypotheses from
other molecular data for the group. This indicates that DNA sequences in
this region are not homologous throughout the entire Cicindelidae, but it
leaves open the possibility that this expansion segment can be used for
phylogeny reconstruction within subgroups. The implications of a
phylogenetic approach to the understanding of slippage-like evolution are
discussed.
相似文献
188.
Natalia V. Bobkova Natalia I. Medvinskaya Irina Y. Aleksandrova Inna V. Nesterova Eugenii E. Fesenko 《Electromagnetic biology and medicine》2018,37(3):127-137
Subchronic effect of a weak combined magnetic field (MF), produced by superimposing a constant component, 42 µT and an alternating MF of 0.08 µT, which was the sum of two frequencies of 4.38 and 4.88 Hz, was studied in olfactory bulbectomized (OBE) and transgenic Tg (APPswe, PSEN1) mice, which were used as animal models of sporadic and heritable Alzheimer’s disease (AD) accordingly. Spatial memory was tested in a Morris water maze on the following day after completion of training trials with the hidden platform removed. The amyloid-β (Aβ) level was determined in extracts of the cortex and hippocampus of mice using a specific DOT analysis while the number and dimensions of amyloid plaques were detected after their staining with thioflavin S in transgenic animals. Exposure to the MFs (4 h/day for 10 days) induced the decrease of Aβ level in brain of OBE mice and reduced the number of Aβ plaques in the cortex and hippocampus of Tg animals. However, memory improvement was revealed in Tg mice only, but not in the OBE animals. Here, we suggest that in order to prevent the Aβ accumulation, MFs could be used at early stage of neuronal degeneration in case of AD and other diseases with amyloid protein deposition in other tissues. 相似文献
189.
190.
The impact of chromatin modifiers on the timing of locus replication in mouse embryonic stem cells 总被引:1,自引:0,他引:1 下载免费PDF全文
Jørgensen HF Azuara V Amoils S Spivakov M Terry A Nesterova T Cobb BS Ramsahoye B Merkenschlager M Fisher AG 《Genome biology》2007,8(8):R169