Publications by authors named "Eleni Petrou"

4 Publications

  • Page 1 of 1

Haemostatic profile of riboflavin-treated apheresis platelet concentrates.

Blood Transfus 2021 May 21. Epub 2021 May 21.

Laboratory of Haematology and Blood Bank Unit, Attikon University Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece.

Background: The haemostatic activity of platelet concentrates (PCs) treated with pathogen reduction technology (PRT) remains a subject of debate. Our aim was to investigate the effect of Mirasol PRT on the haemostatic properties of PCs stored in plasma.

Material And Methods: Untreated and Mirasol-treated platelets stored in plasma and derived from ten split double-dose apheresis PCs were evaluated in vitro on days 1, 3 and 5 post collection for functionality, microparticle procoagulation activity (MPA), endogenous thrombin potential (ETP), and haemostatic profile using rotational thromboelastometry (ROTEM).

Results: P-selectin expression was significantly higher in Mirasol-treated platelets compared with untreated counterparts on days 3 and 5 (p=0.003 and p=0.002, respectively). Clot strength, as shown by EXTEM maximum clot firmness (MCF), was significantly lower in the Mirasol-treated platelets at all time points (days 1, 3, 5) than in untreated platelets (p=0.009, p<0.001, p<0.001, respectively). There was a considerable increase in MPA over time (p<0.001) and this was significantly higher in the Mirasol-treated platelets on day 5 (p=0.015). A notable acceleration of decrease in ETP values was observed for Mirasol-treated PCs over time (p<0.001), with significant differences between PRT-treated and untreated PCs on days 3 and 5 (p=0.038 and p=0.019, respectively). Clot strength attenuation was significantly associated with pH reduction (p<0.001, Spearman's rho: 0.84), increased microparticle procoagulant activity (p<0.001, Spearman's rho: -0.75), and with decreased ETP (p<0.032, Spearman's rho: 0.41).

Discussion: Increased platelet activation induced by PRT treatment leads to a decrease in in vitro haemostatic capacity as seen by reduced clot strength and thrombin generation capacity over time. The clinical relevance of this needs to be investigated.
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May 2021

Functional genetic diversity in an exploited marine species and its relevance to fisheries management.

Proc Biol Sci 2021 02 24;288(1945):20202398. Epub 2021 Feb 24.

School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat Street, Seattle WA 98105, USA.

The timing of reproduction influences key evolutionary and ecological processes in wild populations. Variation in reproductive timing may be an especially important evolutionary driver in the marine environment, where the high mobility of many species and few physical barriers to migration provide limited opportunities for spatial divergence to arise. Using genomic data collected from spawning aggregations of Pacific herring () across 1600 km of coastline, we show that reproductive timing drives population structure in these pelagic fish. Within a specific spawning season, we observed isolation by distance, indicating that gene flow is also geographically limited over our study area. These results emphasize the importance of considering both seasonal and spatial variation in spawning when delineating management units for herring. On several chromosomes, we detected linkage disequilibrium extending over multiple Mb, suggesting the presence of chromosomal rearrangements. Spawning phenology was highly correlated with polymorphisms in several genes, in particular , which influences the development of retinal photoreceptors in vertebrates. is probably within a chromosomal rearrangement in Pacific herring and is also associated with spawn timing in Atlantic herring (). The observed genetic diversity probably underlies resource waves provided by spawning herring. Given the ecological, economic and cultural significance of herring, our results support that conserving intraspecific genetic diversity is important for maintaining current and future ecosystem processes.
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February 2021

Intraspecific DNA contamination distorts subtle population structure in a marine fish: Decontamination of herring samples before restriction-site associated sequencing and its effects on population genetic statistics.

Mol Ecol Resour 2019 Sep 17;19(5):1131-1143. Epub 2019 Jun 17.

School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington.

Wild specimens are often collected in challenging field conditions, where samples may be contaminated with the DNA of conspecific individuals. This contamination can result in false genotype calls, which are difficult to detect, but may also cause inaccurate estimates of heterozygosity, allele frequencies and genetic differentiation. Marine broadcast spawners are especially problematic, because population genetic differentiation is low and samples are often collected in bulk and sometimes from active spawning aggregations. Here, we used contaminated and clean Pacific herring (Clupea pallasi) samples to test (a) the efficacy of bleach decontamination, (b) the effect of decontamination on RAD genotypes and (c) the consequences of contaminated samples on population genetic analyses. We collected fin tissue samples from actively spawning (and thus contaminated) wild herring and nonspawning (uncontaminated) herring. Samples were soaked for 10 min in bleach or left untreated, and extracted DNA was used to prepare DNA libraries using a restriction site-associated DNA (RAD) approach. Our results demonstrate that intraspecific DNA contamination affects patterns of individual and population variability, causes an excess of heterozygotes and biases estimates of population structure. Bleach decontamination was effective at removing intraspecific DNA contamination and compatible with RAD sequencing, producing high-quality sequences, reproducible genotypes and low levels of missing data. Although sperm contamination may be specific to broadcast spawners, intraspecific contamination of samples may be common and difficult to detect from high-throughput sequencing data and can impact downstream analyses.
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September 2019

Environmental symbiont acquisition may not be the solution to warming seas for reef-building corals.

PLoS One 2010 Oct 7;5(10):e13258. Epub 2010 Oct 7.

Graduate Program in Evolution, Ecology and Behavior, Department of Geology, University at Buffalo, Buffalo, New York, United States of America.

Background: Coral reefs worldwide are in decline. Much of the mortality can be attributed to coral bleaching (loss of the coral's intracellular photosynthetic algal symbiont) associated with global warming. How corals will respond to increasing oceanic temperatures has been an area of extensive study and debate. Recovery after a bleaching event is dependent on regaining symbionts, but the source of repopulating symbionts is poorly understood. Possibilities include recovery from the proliferation of endogenous symbionts or recovery by uptake of exogenous stress-tolerant symbionts.

Methodology/principal Findings: To test one of these possibilities, the ability of corals to acquire exogenous symbionts, bleached colonies of Porites divaricata were exposed to symbiont types not normally found within this coral and symbiont acquisition was monitored. After three weeks exposure to exogenous symbionts, these novel symbionts were detected in some of the recovering corals, providing the first experimental evidence that scleractinian corals are capable of temporarily acquiring symbionts from the water column after bleaching. However, the acquisition was transient, indicating that the new symbioses were unstable. Only those symbiont types present before bleaching were stable upon recovery, demonstrating that recovery was from the resident in situ symbiont populations.

Conclusions/significance: These findings suggest that some corals do not have the ability to adjust to climate warming by acquiring and maintaining exogenous, more stress-tolerant symbionts. This has serious ramifications for the success of coral reefs and surrounding ecosystems and suggests that unless actions are taken to reverse it, climate change will lead to decreases in biodiversity and a loss of coral reefs.
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October 2010