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排序方式: 共有198条查询结果,搜索用时 31 毫秒
91.
Miasoedova EE Golubeva EK Prorokova MV Nazarov SB 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2002,88(1):32-37
The study investigates into the role of exogenous nitric oxide (NO) in erythrophagocytosis in rats in vitro. The data indicate that NO enhances the ability of macrophages to adhere and ingest erythrocytes with the rise of nitric oxide concentration in cultural medium. NO influence on red blood cells has been shown to be more significant than its effects on macrophages. The reaction of NO with macrophages results in promotion of initial stages of erythrophagocytosis: macrophages' ability of adhering to the plate and to adhere erythrocytes increases. However, the final stages of erythrophagocytosis are activated just by the influence of NO on red blood cells. Therefore our results have demonstrated that the target point for NO is erythrocyte. We have also confirmed that NO effects are dose-dependent. 相似文献
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Golubeva EB 《Parazitologiia》2000,34(2):100-110
The development of Ichthyocotylurus variegatus from metacercariae to ovigerous adults in the natural definitive host (Larus ridibundus) was examined at 24 h intervals. The metacercariae develop to the adults through a somatic growth of hindbody; the gametogeny and vitellogenesis take 4-6 days. During the first day of development the pair of testes are separated from the genital anlage. The ovary differentiates one day later. Genital ducts are completely differentiated on 4th day after the beginning of spermatogenesis and cogenesis. The vitelline cells developed from 2nd to 5th day. They take an origin from the subtegumental cells of hindbody. The hind part of uterus in strigeoid adults is identical to the metraterm of other trematodes. The spermaduct along all its length works as a spermatic bladder. 相似文献
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Aliphatic polyamines, being a versatile class of organic compounds, are widely used in many fields of medicine and organic chemistry. However, the general approach to the synthesis of chiral aliphatic polyamines has been still undeveloped. Here, we describe a new method for the synthesis of chiral trifunctional amino compounds, namely hydroxydiamines and triamines. The initial compounds, namely substituted hydroxy- or aminopyrazolidines and pyrazolines, are readily available using convenient stereoselective methods developed earlier by us. The proposed method allows synthesizing of chiral diaminoalcohols and triamines, which are the analogs of a well-known anti-TB drug, namely ethambutol, and cannot be obtained alternatively. The key step of the synthesis is N-N bond cleavage in substituted hydroxy- or aminopyrazolidines and pyrazolines with borane-tetrahydrofuran complex; other known methods for N-N bond cleavage turned out to be ineffective. The main advantage of the proposed method is the retention of a certain configuration of stereocenters in the course of the reaction. Six new chiral diasteomerically pure substituted hydroxydiamines and triamines and the enantiomerically pure triamine with four chiral centers were synthesized and characterized using NMR, IR and mass spectroscopy, as well as elemental analysis. 相似文献
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Andreeva IG Golubeva LI Kuvaeva TM Gak ER Katashkina JI Mashko SV 《FEMS microbiology letters》2011,318(1):55-60
Pantoea ananatis accumulates gluconate during aerobic growth in the presence of glucose. Computer analysis of the P. ananatis SC17(0) sequenced genome revealed an ORF encoding a homologue (named gcd) of the mGDH (EC 1.1.99.17) apoenzyme from Escherichia coli and a putative pyrroloquinoline quinone (PQQ) biosynthetic operon homologous to pqqABCDEF from Klebsiella pneumoniae. Construction of Δgcd and Δpqq mutants of P. ananatis confirmed the proposed functions of these genetic elements. The P. ananatis pqqABCDEF was cloned in vivo and integrated into the chromosomes of P. ananatis and E. coli according to the Dual In/Out strategy. Introduction of a second copy of pqqABCDEF to P. ananatis SC17(0) doubled the accumulation of PQQ. Integration of the operon into E. coli MG1655ΔptsGΔmanXY restored the growth of bacteria on glucose. The obtained data show the essential role of pqqABCDEF in PQQ biosynthesis in P. ananatis and E. coli. We propose that the cloned operon could be useful for an efficient phosphoenolpyruvate-independent glucose consumption pathway due to glucose oxidation and construction of E. coli strains with the advantage of phosphoenolpyruvate-derived metabolite production. 相似文献