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排序方式: 共有372条查询结果,搜索用时 15 毫秒
61.
Viera Danielisová Miroslav Gottlieb Miroslava Némethová Petra Kravčuková Iveta Domoráková Eva Mechírová Jozef Burda 《Cellular and molecular neurobiology》2009,29(6-7):871-878
Aims The present study was undertaken to evaluate possible neuroprotective effect of bradykinin against delayed neuronal death in hippocampal CA1 neurons if applied two days after transient forebrain ischemia in the rat. Methods Transient forebrain ischemia was induced in male Wistar rats by four-vessel occlusion for 8 min. To assess efficacy of bradykinin as a new stressor for delayed postconditioning we used two experimental groups of animals: ischemia 8 min and 3 days of survival, and ischemia 8 min and 3 days of survival with i.p. injection of bradykinin (150 μg/kg) applied 48 h after ischemia. Results We found extensive neuronal degeneration in the CA1 region at day 3 after ischemia/reperfusion. The postischemic neurodegeneration was preceded by increased activity of mitochondrial enzyme MnSOD in cytoplasm, indicating release of MnSOD from mitochondria in the process of delayed neuronal death. Increased cytosolic cytochrome c and subsequently caspase-3 activation are additional signs of neuronal death via the mitochondrial pathway. Bradykinin administration significantly attenuated ischemia-induced neuronal death, and also suppressed the release of MnSOD, and cytochrome c, and prevented caspase-3 activation. Conclusions Bradykinin can be used as an effective stressor able to prevent mitochondrial failure leading to apoptosis-like delayed neuronal death in postischemic rat hippocampus. 相似文献
62.
Derenko M Malyarchuk B Grzybowski T Denisova G Rogalla U Perkova M Dambueva I Zakharov I 《PloS one》2010,5(12):e15214
More than a half of the northern Asian pool of human mitochondrial DNA (mtDNA) is fragmented into a number of subclades of haplogroups C and D, two of the most frequent haplogroups throughout northern, eastern, central Asia and America. While there has been considerable recent progress in studying mitochondrial variation in eastern Asia and America at the complete genome resolution, little comparable data is available for regions such as southern Siberia--the area where most of northern Asian haplogroups, including C and D, likely diversified. This gap in our knowledge causes a serious barrier for progress in understanding the demographic pre-history of northern Eurasia in general. Here we describe the phylogeography of haplogroups C and D in the populations of northern and eastern Asia. We have analyzed 770 samples from haplogroups C and D (174 and 596, respectively) at high resolution, including 182 novel complete mtDNA sequences representing haplogroups C and D (83 and 99, respectively). The present-day variation of haplogroups C and D suggests that these mtDNA clades expanded before the Last Glacial Maximum (LGM), with their oldest lineages being present in the eastern Asia. Unlike in eastern Asia, most of the northern Asian variants of haplogroups C and D began the expansion after the LGM, thus pointing to post-glacial re-colonization of northern Asia. Our results show that both haplogroups were involved in migrations, from eastern Asia and southern Siberia to eastern and northeastern Europe, likely during the middle Holocene. 相似文献
63.
Boris Malyarchuk Miroslava Derenko Tomasz Grzybowski Maria Perkova Urszula Rogalla Tomas Vanecek Iosif Tsybovsky 《PloS one》2010,5(4)
It is generally accepted that the most ancient European mitochondrial haplogroup, U5, has evolved essentially in Europe. To resolve the phylogeny of this haplogroup, we completely sequenced 113 mitochondrial genomes (79 U5a and 34 U5b) of central and eastern Europeans (Czechs, Slovaks, Poles, Russians and Belorussians), and reconstructed a detailed phylogenetic tree, that incorporates previously published data. Molecular dating suggests that the coalescence time estimate for the U5 is ∼25–30 thousand years (ky), and ∼16–20 and ∼20–24 ky for its subhaplogroups U5a and U5b, respectively. Phylogeographic analysis reveals that expansions of U5 subclusters started earlier in central and southern Europe, than in eastern Europe. In addition, during the Last Glacial Maximum central Europe (probably, the Carpathian Basin) apparently represented the area of intermingling between human flows from refugial zones in the Balkans, the Mediterranean coastline and the Pyrenees. Age estimations amounting for many U5 subclusters in eastern Europeans to ∼15 ky ago and less are consistent with the view that during the Ice Age eastern Europe was an inhospitable place for modern humans. 相似文献
64.
Miroslava Rakocevic Simoni Fernanda Martim 《International journal of biometeorology》2011,55(2):161-171
To assess differences in the lag-effect pattern in the relationship between yerba-mate biennial growth and environmental factors,
a time-series analysis was performed. A generalized Poisson regression model was used to control time trends, temperature,
growing degree days (GDD), rainfalls and night length (NL). It was hypothesized that the active growth and growth pauses in
yerba-mate are controlled endogenously and modified by environment, and that genders would respond differently to environmental
modifications. The patterns in the lag effect from the distributed-lag models were similar to those of time-series models
with meteorological data means with lag = 0. GDD and NL were principal factors affecting biennial yerba-mate shoot elongation
and the number of green leaves of females grown in monoculture, besides their significant effects on metamer emission and
leaf area in males grown in monoculture. NL also had a significant influence on shoot elongation and leaf area of both genders
grown in forest understorey (FUS), indicating that yerba-mate growth is synchronized by an internal clock sensitive to temperature
adjustments. The morphological plasticity and the adaptation efforts of yerba-mate were more pronounced in monoculture than
in FUS. Sexual dimorphism was expressed—males were more sensitive to environmental changes than females, especially in monoculture.
Growth modifications were much more intense when plants were grown in a cultivation system that is less like yerba-mate natural
habitat (monoculture) than in one resembling its natural habitat (FUS). Our data support the ecological specialization theory. 相似文献
65.
The effects of a selective inducible nitric oxide synthase inhibitor aminoguanidine (AG) on neuronal cells survival in hippocampal
CA1 region after middle cerebral artery occlusion (MCAO) were examined. Transient focal cerebral ischemia was induced in rats
by 60 or 90 min of MCAO, followed by 7 days of reperfusion. AG treatment (150 mg/kg i.p.) significantly reduced total infarct
volumes: by 70% after 90 min MCAO and by 95% after 60 min MCAO, compared with saline-treated ischemic group. The number of
degenerating neurons in hippocampal CA1 region was also markedly lower in aminoguanidine-treated ischemic groups compared
to ischemic groups without AG-treatment. The number of iNOS-positive cells significantly increased in the hippocampal CA1
region of ischemic animals, whereas it was reduced in AG-treated rats. Our findings demonstrate that aminoguanidine decreases
ischemic brain damage and improves neurological recovery after transient focal ischemia induced by MCAO. 相似文献
66.
Alessia Cariani Miroslava Atanassova Dorte Bekkevold Gary R. Carvalho Montserrat Espiñeira Fabio Fiorentino Germana Garofalo Audrey J. Geffen Jakob. H. Hansen Sarah J. Helyar Einar E. Nielsen Rob Ogden Tomaso Patarnello Marco Stagioni FishPopTrace Consortium Fausto Tinti Luca Bargelloni 《Molecular ecology》2014,23(1):118-135
Shallow population structure is generally reported for most marine fish and explained as a consequence of high dispersal, connectivity and large population size. Targeted gene analyses and more recently genome‐wide studies have challenged such view, suggesting that adaptive divergence might occur even when neutral markers provide genetic homogeneity across populations. Here, 381 SNPs located in transcribed regions were used to assess large‐ and fine‐scale population structure in the European hake (Merluccius merluccius), a widely distributed demersal species of high priority for the European fishery. Analysis of 850 individuals from 19 locations across the entire distribution range showed evidence for several outlier loci, with significantly higher resolving power. While 299 putatively neutral SNPs confirmed the genetic break between basins (FCT = 0.016) and weak differentiation within basins, outlier loci revealed a dramatic divergence between Atlantic and Mediterranean populations (FCT range 0.275–0.705) and fine‐scale significant population structure. Outlier loci separated North Sea and Northern Portugal populations from all other Atlantic samples and revealed a strong differentiation among Western, Central and Eastern Mediterranean geographical samples. Significant correlation of allele frequencies at outlier loci with seawater surface temperature and salinity supported the hypothesis that populations might be adapted to local conditions. Such evidence highlights the importance of integrating information from neutral and adaptive evolutionary patterns towards a better assessment of genetic diversity. Accordingly, the generated outlier SNP data could be used for tackling illegal practices in hake fishing and commercialization as well as to develop explicit spatial models for defining management units and stock boundaries. 相似文献
67.
Miroslav Novaković Miroslava Stanković Ivan Vučković Nina Todorović Snežana Trifunović Danijela Apostolović Boris Mandić Milan Veljić Petar Marin Vele Tešević Vlatka Vajs Slobodan Milosavljević 《化学与生物多样性》2014,11(6):872-885
Nine diarylheptanoids, 1 – 9 , catechin ( 11 ), and a phenolic glucoside, 10 , were isolated from the bark of green alder (Alnus viridis). Four of the isolated compounds, i.e., 2, 5, 8, 10 , are new. The structures of 1 – 11 were determined on the basis of spectroscopic data. All isolated compounds were evaluated for their in vitro protective effects on chromosome aberrations in peripheral human lymphocytes using cytokinesis‐block micronucleus (CBMN) assay. Almost all of them exerted a pronounced effect of decreasing DNA damage of human lymphocytes, acting stronger than the known synthetic protector amifostine. 相似文献
68.
Alexia Cardona Luca Pagani Tiago Antao Daniel J. Lawson Christina A. Eichstaedt Bryndis Yngvadottir Ma Than Than Shwe Joseph Wee Irene Gallego Romero Srilakshmi Raj Mait Metspalu Richard Villems Eske Willerslev Chris Tyler-Smith Boris A. Malyarchuk Miroslava V. Derenko Toomas Kivisild 《PloS one》2014,9(5)
Following the dispersal out of Africa, where hominins evolved in warm environments for millions of years, our species has colonised different climate zones of the world, including high latitudes and cold environments. The extent to which human habitation in (sub-)Arctic regions has been enabled by cultural buffering, short-term acclimatization and genetic adaptations is not clearly understood. Present day indigenous populations of Siberia show a number of phenotypic features, such as increased basal metabolic rate, low serum lipid levels and increased blood pressure that have been attributed to adaptation to the extreme cold climate. In this study we introduce a dataset of 200 individuals from ten indigenous Siberian populations that were genotyped for 730,525 SNPs across the genome to identify genes and non-coding regions that have undergone unusually rapid allele frequency and long-range haplotype homozygosity change in the recent past. At least three distinct population clusters could be identified among the Siberians, each of which showed a number of unique signals of selection. A region on chromosome 11 (chr11:66–69 Mb) contained the largest amount of clustering of significant signals and also the strongest signals in all the different selection tests performed. We present a list of candidate cold adaption genes that showed significant signals of positive selection with our strongest signals associated with genes involved in energy regulation and metabolism (CPT1A, LRP5, THADA) and vascular smooth muscle contraction (PRKG1). By employing a new method that paints phased chromosome chunks by their ancestry we distinguish local Siberian-specific long-range haplotype signals from those introduced by admixture. 相似文献
69.
Jan ?ilhavy Václav Zídek Petr Mlejnek Vladimír Landa Miroslava ?imáková Hynek Strnad Olena Oliyarnyk Vojtěch ?kop Ludmila Kazdová Theodore Kurtz Michal Pravenec 《PloS one》2014,9(7)
Inflammation and oxidative stress have been implicated in the pathogenesis of metabolic disturbances. Esters of fumaric acid, mainly dimethyl fumarate, exhibit immunomodulatory, anti-inflammatory, and anti-oxidative effects. In the current study, we tested the hypothesis that fumaric acid ester (FAE) treatment of an animal model of inflammation and metabolic syndrome, the spontaneously hypertensive rat transgenically expressing human C-reactive protein (SHR-CRP), will ameliorate inflammation, oxidative stress, and metabolic disturbances. We studied the effects of FAE treatment by administering Fumaderm, 10 mg/kg body weight for 4 weeks, to male SHR-CRP. Untreated male SHR-CRP rats were used as controls. All rats were fed a high sucrose diet. Compared to untreated controls, rats treated with FAE showed significantly lower levels of endogenous CRP but not transgenic human CRP, and amelioration of inflammation (reduced levels of serum IL6 and TNFα) and oxidative stress (reduced levels of lipoperoxidation products in liver, heart, kidney, and plasma). FAE treatment was also associated with lower visceral fat weight and less ectopic fat accumulation in liver and muscle, greater levels of lipolysis, and greater incorporation of glucose into adipose tissue lipids. Analysis of gene expression profiles in the liver with Affymetrix arrays revealed that FAE treatment was associated with differential expression of genes in pathways that involve the regulation of inflammation and oxidative stress. These findings suggest potentially important anti-inflammatory, anti-oxidative, and metabolic effects of FAE in a model of inflammation and metabolic disturbances induced by human CRP. 相似文献
70.
Solid phase technique on p-methylbenzhydrylamine resin wasused for the synthesis of eight analogs of oxytocin and 8-D-homoarginine vasopressin with the non-coded amino acids L- or D-2,3,4,5,6-pentamethylphenylalanine and L- or D-4-phenylphenylalanine in position 2. The preparation of theabove mentioned non-coded amino acids is described as well.All eight analogs were found to be potent inhibitors ofoxytocin activity in the uterotonic in vitro test in theabsence of Mg2+ ions. In the uterotonic test invitro in the presence of Mg2+ and in the test invivo, their potency is strongly decreased or completelyabolished. The substances are also weak pressor inhibitors.The L or D configuration does not seem to influence theactivity significantly. 相似文献