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31.
Roxani Angelopoulou Giagkos Lavranos Panagiota Manolakou 《Reproductive biology and endocrinology : RB&E》2008,6(1):12
Chromosomal sex determination is a widely distributed strategy in nature. In the most classic scenario, one sex is characterized
by a homologue pair of sex chromosomes, while the other includes two morphologically and functionally distinct gonosomes.
In mammalian diploid cells, the female is characterized by the presence of two identical X chromosomes, while the male features
an XY pair, with the Y bearing the major genetic determinant of sex, i.e. the SRY gene. In other species, such as the fruitfly,
sex is determined by the ratio of autosomes to X chromosomes. Regardless of the exact mechanism, however, all these animals
would exhibit a sex-specific gene expression inequality, due to the different number of X chromosomes, a phenomenon inhibited
by a series of genetic and epigenetic regulatory events described as "dosage compensation". Since adequate available data
is currently restricted to worms, flies and mammals, while for other groups of animals, such as reptiles, fish and birds it
is very limited, it is not yet clear whether this is an evolutionary conserved mechanism. However certain striking similarities
have already been observed among evolutionary distant species, such as Drosophila melanogaster and Mus musculus. These mainly
refer to a) the need for a counting mechanism, to determine the chromosomal content of the cell, i.e. the ratio of autosomes
to gonosomes (a process well understood in flies, but still hypothesized in mammals), b) the implication of non-translated,
sex-specific, regulatory RNAs (roX and Xist, respectively) as key elements in this process and the location of similar mediators
in the Z chromosome of chicken c) the inclusion of a chromatin modification epigenetic final step, which ensures that gene
expression remains stably regulated throughout the affected area of the gonosome. This review summarizes these points and
proposes a possible role for comparative genetics, as they seem to constitute proof of maintained cell economy (by using the
same basic regulatory elements in various different scenarios) throughout numerous centuries of evolutionary history. 相似文献
32.
Panagiota Manolakou Roxani Angelopoulou Chris Bakoyiannis Elias Bastounis 《Reproductive biology and endocrinology : RB&E》2009,7(1):44
Cardiovascular disease incidence rates have long been known to significantly differ between the two sexes. Estrogens alone
fail to explain this phenomenon, bringing an increasing amount of attention to the role of androgens. Contrary to what was
initially hypothesized, androgens seem to have an overall cardioprotective effect, especially in men. Recent studies and published
data continue to support this notion displaying a consistent inverse correlation with atherosclerosis progression and cardiovascular
disease both in regressive and prospective study models. Clinical studies have also revealed what seems to be a differential
androgenic effect on various cardiovascular risk factors between men and women. Further insight indicates that in order to
avoid confusion it may be also preferable to separately examine the effects of endogenous androgen levels from exogenous testosterone
administration, as well as discern the differential results of low to normal and supraphysiological administration doses.
This review summarizes old and recent data according to the above distinctions, in an attempt to further our understanding
of the role of androgens in cardiovascular disease. 相似文献
33.
Erwan Plouguerné Efstathia Ioannou Panagiota Georgantea Constantinos Vagias Vassilios Roussis Claire Hellio Edouard Kraffe Valérie Stiger-Pouvreau 《Marine biotechnology (New York, N.Y.)》2010,12(1):52-61
The purification of the chloroform extract from the brown invasive macroalga Sargassum muticum, through a series of chromatographic separations, yielded 12 fractions that were tested against strains of bacteria, microalgae,
and fungi involved in marine biofilm formation. The chemical composition of four (a, c, g, and k) out of the six fractions
that exhibited anti-microfouling activity was investigated. Fraction a contained saturated and unsaturated linear hydrocarbons
(C12–C27). Arachidonic acid was identified as the major metabolite in fraction c whereas fraction g contained mainly palmitic, linolenic,
and palmitoleic acids. Fraction k was submitted to further purification yielding the fraction kAcaF1e that was composed of
galactoglycerolipids, active against the growth of two of the four bacterial strains (Shewanella putrefaciens and Polaribacter irgensii) and all tested fungi. These promising results, in particular the isolation and the activity of galactoglycerolipids, attest
the potential of the huge biomass of S. muticum as a source of new environmentally friendly antifouling compounds. 相似文献
34.
Harald Biessmann Evi Andronopoulou Max R. Biessmann Vassilis Douris Spiros D. Dimitratos Elias Eliopoulos Patrick M. Guerin Kostas Iatrou Robin W. Justice Thomas Kr?ber Osvaldo Marinotti Panagiota Tsitoura Daniel F. Woods Marika F. Walter 《PloS one》2010,5(3)
Haematophagous insects are frequently carriers of parasitic diseases, including malaria. The mosquito Anopheles gambiae is the major vector of malaria in sub-Saharan Africa and is thus responsible for thousands of deaths daily. Although the role of olfaction in A. gambiae host detection has been demonstrated, little is known about the combinations of ligands and odorant binding proteins (OBPs) that can produce specific odor-related responses in vivo. We identified a ligand, indole, for an A. gambiae odorant binding protein, AgamOBP1, modeled the interaction in silico and confirmed the interaction using biochemical assays. RNAi-mediated gene silencing coupled with electrophysiological analyses confirmed that AgamOBP1 binds indole in A. gambiae and that the antennal receptor cells do not respond to indole in the absence of AgamOBP1. This case represents the first documented instance of a specific A. gambiae OBP–ligand pairing combination, demonstrates the significance of OBPs in odor recognition, and can be expanded to the identification of other ligands for OBPs of Anopheles and other medically important insects. 相似文献
35.
A time series of survey abundance indices for commercially important demersal fish and cephalopod species, inhabiting the
narrow continental shelf of the southern Aegean Sea, is analyzed in relation to the topography of the area in order to evaluate
the impact of different spatial fishery bans on the bottom-trawl fishery. With reference to the current situation, results
suggested that implementation of the 1967/2006 EC Regulation, which bans bottom-trawl activities within 1.5 NM off the coast,
will significantly increase (20–80%, depending on the species) the proportion of the populations that are inaccessible to
the bottom-trawl fishery. It might also result in shifting of fishing activities toward deeper waters, adding fishing pressure
onto slope resources inhabiting the slope. As depth determines, to a large extent, the distribution pattern of the species,
it constitutes a variable of crucial importance for the spatial management of marine fisheries and should be taken into account
when adopting relevant management regimes. 相似文献
36.
Spiliopoulos S Diamantopoulos A Katsanos K Ravazoula P Karnabatidis D Siablis D 《Cryobiology》2011,(3):267-272
Purpose
To in vivo investigate the histological response after single and double cryoplasty therapy in a rabbit iliac artery model.Materials and methods
In total, 40 New Zealand White rabbits underwent percutaneous transluminal angioplasty of the iliac artery using either PolarCath balloon or a conventional angioplasty balloon of equal diameter. Arterial injury, inflammatory response and smooth muscle cells (SMC) apoptosis with the TUNEL (Terminal deoxynucleotidyl transferase dUTP Nick End Labeling) immunohistochemical assay were analyzed. Rabbits were divided between single or double balloon inflation and histological results were compared between cryoplasty and control angioplasty both at 30 min and 72 h.Results
Arterial injury and wall inflammation scores were low and similar between cryoplasty and control groups after single and double balloon inflation. Compared to conventional balloon angioplasty, Polarcath cryoplasty demonstrated superior SMC apoptosis after single inflation at 30 min [12.0 ± 1.2 cells/(0.025 mm)2 vs 7.0 ± 1.5 cells/(0.025 mm)2, p = 0.002], single inflation at 72 h [9.0 ± 1.0 cells/(0.025 mm)2 vs 5.4 ± 1.4 cells/(0.025 mm)2, p = 0.001], double inflation at 30 min [11.6 ± 1.5 cells/(0.025 mm)2 vs 6.8 ± 1.4 cells/(0.025 mm)2, p = 0.001] and double inflation at 72 h [9.2 ± 0.8 cells/(0.025 mm)2 vs 5.0 ± 0.7 cells/(0.025 mm)2, p = 0.001]. There were no significant differences in apoptosis between single and double cryoplasty application at 30 min and 72 h.Conclusion
Cryoplasty demonstrated superior rates of SMC apoptosis at 30 min and 72 h and was associated to relatively low arterial injury and inflammation scores. An immediate second PolarCath inflation did not achieve superior apoptosis. 相似文献37.
Athanassios Kotsinas Panagiota Papanagnou Panagiotis Galanos Daniel Schramek Paul Townsend Josef M Penninger 《Cell cycle (Georgetown, Tex.)》2014,13(8):1227-1236
Sensing, integrating, and processing of stressogenic signals must be followed by accurate differential response(s) for a cell to survive and avoid malignant transformation. The DNA damage response (DDR) pathway is vital in this process, as it deals with genotoxic/oncogenic insults, having p53 as a nodal effector that performs most of the above tasks. Accumulating data reveal that other pathways are also involved in the same or similar processes, conveying also to p53. Emerging questions are if, how, and when these additional pathways communicate with the DDR axis. Two such stress response pathways, involving the MKK7 stress-activated protein kinase (SAPK) and ARF, have been shown to be interlocked with the ATM/ATR-regulated DDR axis in a highly ordered manner. This creates a new landscape in the DDR orchestrated response to genotoxic/oncogenic insults that is currently discussed. 相似文献
38.
Vasiliki?Chondrou Eleana?F.?Stavrou Georgios?Markopoulos Alexandra?Kouraklis-Symeonidis Vasilios?Fotopoulos Argiris?Symeonidis Efthymia?Vlachaki Panagiota?Chalkia George?P.?Patrinos Adamantia?Papachatzopoulou Argyro?SgourouEmail author 《Human genomics》2018,12(1):45
Background
We aimed to clarify the emerging epigenetic landscape in a group of genes classified as “modifier genes” of the β-type globin genes (HBB cluster), known to operate in trans to accomplish the two natural developmental switches in globin expression, from embryonic to fetal during the first trimester of conception and from fetal to adult around the time of birth. The epigenetic alterations were determined in adult sickle cell anemia (SCA) homozygotes and SCA/β-thalassemia compound heterozygotes of Greek origin, who are under hydroxyurea (HU) treatment. Patients were distinguished in HU responders and HU non-responders (those not benefited from the HU) and both, and in vivo and in vitro approaches were implemented.Results
We examined the CpG islands’ DNA methylation profile of BCL11A, KLF1, MYB, MAP3K5, SIN3A, ZBTB7A, and GATA2, along with γ-globin and LRF/ZBTB7A expression levels. In vitro treatment of hematopoietic stem cells (HSCs) with HU induced a significant DNA hypomethylation pattern in ZBTB7A (p*, 0.04) and GATA2 (p*, 0.03) CpGs exclusively in the HU non-responders. Also, this group of patients exhibited significantly elevated baseline methylation patterns in ZBTB7A, before the HU treatment, compared to HU responders (p*, 0.019) and to control group of healthy individuals (p*, 0.021), which resembles a potential epigenetic barrier for the γ-globin expression. γ-Globin expression in vitro matched with detected HbF levels during patients’ monitoring tests (in vivo) under HU treatment, implying a good reproducibility of the in vitro HU epigenetic effect. LRF/ZBTB7A expression was elevated only in the HU non-responders under the influence of HU.Conclusions
This is one of the very first pharmacoepigenomic studies indicating that the hypomethylation of ZBTB7A during HU treatment enhances the LRF expression, which by its turn suppresses the HbF resumption in the HU non-responders. Its role as an epigenetic regulator of hemoglobin switching is also supported by the wide distribution of ZBTB7A-binding sites within the 5′ CpG sequences of all studied human HBB cluster “modifier genes.” Also, the baseline methylation level of selective CpGs in ZBTB7A and GATA2 could be an indicator of the negative HU response among the β-type hemoglobinopathy patients.39.
40.
Stefanie Keller Valerio Bartolino Manuel Hidalgo Isabella Bitetto Loredana Casciaro Danila Cuccu Antonio Esteban Cristina Garcia Germana Garofalo Marios Josephides Angelique Jadaud Evgenia Lefkaditou Porzia Maiorano Chiara Manfredi Bojan Marceta Enric Massutí Reno Micallef Panagiota Peristeraki Giulio Relini Paolo Sartor Maria Teresa Spedicato George Tserpes Antoni Quetglas 《PloS one》2016,11(1)