17 research outputs found
Maritime route of colonization of Europe
The Neolithic populations, which colonized Europe approximately 9,000 y ago, presumably migrated from Near East to Anatolia and from there to Central Europe through Thrace and the Balkans. An alternative route would have been island hopping across the Southern European coast. To test this hypothesis, we analyzed genome-wide DNA polymorphisms on populations bordering the Mediterranean coast and from Anatolia and mainland Europe. We observe a striking structure correlating genes with geography around the Mediterranean Sea with characteristic east to west clines of gene flow. Using population network analysis, we also find that the gene flow from Anatolia to Europe was through Dodecanese, Crete, and the Southern European coast, compatible with the hypothesis that a maritime coastal route was mainly used for the migration of Neolithic farmers to Europe
Development of anaytical methods for determining arsenic species and their interactions in environmental - biological systems
Arsenic is ubiquitous in the environment, with its toxicity being
dependant on its oxidation state and its chemical form. People are exposed to
arsenic mainly through drinking water and seafood. Chronic exposure to elevated
concentrations of inorganic arsenic is believed to cause adverse health effects and
contribute to cancers of the lung, bladder and skin.
Last years, a series of novel arsenic species has been detected and
characterised in a variety of biological samples. These species may contribute
significantly in the biogeochemistry and metabolism of arsenic, while, on the
other hand, the toxicity of these compounds, which are considered to be
metabolized in vivo to other species of unknown toxicity, has not been fully
evaluated yet.
A very important tool for the identification of new arsenic compounds is
mass spectrometry coupled with liquid chromatography HPLC. Especially,
Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Electrospray
Ionization Mass Spectrometry (ESI-MS), in combination with HPLC, have been
applied for the detection and characterization of numerous arsenic species, which
are found at very low concentrations in environmental and biological samples.
The objective of the present study was the development of sensitive and
selective methods for the identification of new arsenic species in biological
samples, and then the application of these methods in order to study the in vitro
metabolism of inorganic arsenic. The analyses that were carried out during the
present study were based on reversed phase and anion exchange HPLC methods
coupled with both ICP-MS and ESI-MS/MS techniques.Το αρσενικό αποτελεί ένα στοιχείο ευρέως διαδεδομένο στην φύση, του
οποίου η τοξικότητα εξαρτάται από την οξειδωτική κατάσταση και το χημικό τύπο,
με τον οποίο συναντάται. Η έκθεση του ανθρώπου σε αυτό, γίνεται, κυρίως, μέσω
του φαγητού και του νερού, ενώ, ιδιαίτερα υψηλές συγκεντρώσεις του στοιχείου,
έχουν αναφερθεί σε θαλασσινές τροφές. Τα τελευταία χρόνια, έχει παρατηρηθεί
σημαντική πρόοδος στον τομέα της ειδοταυτοποίησης του αρσενικού, με μια σειρά
από καινούριες ενώσεις να έχουν ανιχνευτεί και ταυτοποιηθεί, σε μεγάλο αριθμό
βιολογικών δειγμάτων. Λόγω της άμεσης συσχέτισης του αρσενικού με την
ανθρώπινη υγεία, παρουσιάζουν ιδιαίτερο ενδιαφέρον οι προσπάθειες ανίχνευσης
και ταυτοποίησης καινούριων ειδών του στοιχείου, τα οποία, πιθανόν, να
διαδραματίζουν σημαντικό ρόλο στην βιοχημεία, το μεταβολισμό και τον
γεωχημικό του κύκλο. Ένα πολύ σημαντικό εργαλείο για την ταυτοποίηση
καινούριων ενώσεων αρσενικού, είναι οι τεχνικές φασματομετρίας μάζας, σε
συνδυασμό με υγρή χρωματογραφία, και, ιδιαίτερα, οι μέθοδοι Υγρής
Χρωματογραφίας Υψηλής Απόδοσης (HPLC), συζευγμένης, τόσο με Φασματομετρία
Μάζας Επαγωγικά Συζευγμένου Πλάσματος (ICP-MS), όσο και με Διαδοχική
Φασματομετρία Μάζας Ιονισμού μέσω Ηλεκτροψεκασμού (ESI-MS/MS).
Προς αυτή την κατεύθυνση στρέφεται η παρούσα διατριβή, της οποίας ο
βασικός στόχος είναι η ανάπτυξη ευαίσθητων και εκλεκτικών μεθόδων, ικανών να
ταυτοποιήσουν καινούριες ενώσεις αρσενικού, ακόμα και αν αυτές συναντώνται σε
πολύ χαμηλές συγκεντρώσεις, στα αναλυόμενα βιολογικά δείγματα. Η in vitro
μελέτη του μεταβολισμού του ανόργανου αρσενικού και η ταυτοποίηση των
τελικών μεταβολιτών, αποτελεί, επίσης, ένα σημαντικό κεφάλαιο της διατριβής
Development of anaytical methods for determining arsenic species and their interactions in environmental - biological systems
Arsenic is ubiquitous in the environment, with its toxicity being
dependant on its oxidation state and its chemical form. People are exposed to
arsenic mainly through drinking water and seafood. Chronic exposure to elevated
concentrations of inorganic arsenic is believed to cause adverse health effects and
contribute to cancers of the lung, bladder and skin.
Last years, a series of novel arsenic species has been detected and
characterised in a variety of biological samples. These species may contribute
significantly in the biogeochemistry and metabolism of arsenic, while, on the
other hand, the toxicity of these compounds, which are considered to be
metabolized in vivo to other species of unknown toxicity, has not been fully
evaluated yet.
A very important tool for the identification of new arsenic compounds is
mass spectrometry coupled with liquid chromatography HPLC. Especially,
Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Electrospray
Ionization Mass Spectrometry (ESI-MS), in combination with HPLC, have been
applied for the detection and characterization of numerous arsenic species, which
are found at very low concentrations in environmental and biological samples.
The objective of the present study was the development of sensitive and
selective methods for the identification of new arsenic species in biological
samples, and then the application of these methods in order to study the in vitro
metabolism of inorganic arsenic. The analyses that were carried out during the
present study were based on reversed phase and anion exchange HPLC methods
coupled with both ICP-MS and ESI-MS/MS techniques.Το αρσενικό αποτελεί ένα στοιχείο ευρέως διαδεδομένο στην φύση, του
οποίου η τοξικότητα εξαρτάται από την οξειδωτική κατάσταση και το χημικό τύπο,
με τον οποίο συναντάται. Η έκθεση του ανθρώπου σε αυτό, γίνεται, κυρίως, μέσω
του φαγητού και του νερού, ενώ, ιδιαίτερα υψηλές συγκεντρώσεις του στοιχείου,
έχουν αναφερθεί σε θαλασσινές τροφές. Τα τελευταία χρόνια, έχει παρατηρηθεί
σημαντική πρόοδος στον τομέα της ειδοταυτοποίησης του αρσενικού, με μια σειρά
από καινούριες ενώσεις να έχουν ανιχνευτεί και ταυτοποιηθεί, σε μεγάλο αριθμό
βιολογικών δειγμάτων. Λόγω της άμεσης συσχέτισης του αρσενικού με την
ανθρώπινη υγεία, παρουσιάζουν ιδιαίτερο ενδιαφέρον οι προσπάθειες ανίχνευσης
και ταυτοποίησης καινούριων ειδών του στοιχείου, τα οποία, πιθανόν, να
διαδραματίζουν σημαντικό ρόλο στην βιοχημεία, το μεταβολισμό και τον
γεωχημικό του κύκλο. Ένα πολύ σημαντικό εργαλείο για την ταυτοποίηση
καινούριων ενώσεων αρσενικού, είναι οι τεχνικές φασματομετρίας μάζας, σε
συνδυασμό με υγρή χρωματογραφία, και, ιδιαίτερα, οι μέθοδοι Υγρής
Χρωματογραφίας Υψηλής Απόδοσης (HPLC), συζευγμένης, τόσο με Φασματομετρία
Μάζας Επαγωγικά Συζευγμένου Πλάσματος (ICP-MS), όσο και με Διαδοχική
Φασματομετρία Μάζας Ιονισμού μέσω Ηλεκτροψεκασμού (ESI-MS/MS).
Προς αυτή την κατεύθυνση στρέφεται η παρούσα διατριβή, της οποίας ο
βασικός στόχος είναι η ανάπτυξη ευαίσθητων και εκλεκτικών μεθόδων, ικανών να
ταυτοποιήσουν καινούριες ενώσεις αρσενικού, ακόμα και αν αυτές συναντώνται σε
πολύ χαμηλές συγκεντρώσεις, στα αναλυόμενα βιολογικά δείγματα. Η in vitro
μελέτη του μεταβολισμού του ανόργανου αρσενικού και η ταυτοποίηση των
τελικών μεταβολιτών, αποτελεί, επίσης, ένα σημαντικό κεφάλαιο της διατριβής
‘Suicide rates in Crete, Greece during the economic crisis: the effect of age, gender, unemployment and mental health service provision’
Abstract Background Recently, suicides in Greece have drawn national and international interest due to the current economic crisis. According to published reports, suicides in Greece have increased up to 40% and Crete has been highlighted as an area with the sharpest increase. Aim To investigate the suicide mortality rates in Crete between 1999 and 2013 and their association with the economic crisis. Methods Data on suicides were selected from the Department of Forensic Medicine files of the University of Crete. Results Our analysis showed that (1) Crete, has the highest suicide mortality rate in Greece, however no significant increase was observed between 1999 and 2013, (2) there were opposing trends between men and women, with women showing a decrease whereas men showed an increase in that period, (3) there was a significant increase of suicides in middle-aged men (40–64 yrs) and elderly, although the highest unemployment rates were observed in young men and women, and (4) finally, there was a regional shift of suicides with a significant decrease in Western Crete and a significant increase in Eastern Crete. Conclusions Although, Crete has the highest suicide mortality rates in Greece, we did not observe an overall increase during the last 15 years, including the period of economic crisis. Furthermore, there was an increase in middle-aged and elderly men, whereas young men and women showed oppositional trends during the years of austerity. This may be related to the culturally different expectations for the two genders, as well as that younger individuals may find refuge to either strong family ties or by immigrating abroad. Finally, the relative increase of suicides in Eastern Crete may be explained by factors, such as the lack of community mental health services in that area
Comprehensive subcellular topologies of polypeptides in Streptomyces
Members of the genus Streptomyces are Gram-positive bacteria that are used as important cell factories to produce secondary metabolites and secrete heterologous proteins. They possess some of the largest bacterial genomes and thus proteomes. Understanding their complex proteomes and metabolic regulation will improve any genetic engineering approach.status: publishe
Comprehensive subcellular topologies of polypeptides in Streptomyces
Tsolis KC, Tsare E-P, Orfanoudaki G, et al. Comprehensive subcellular topologies of polypeptides in Streptomyces. MICROBIAL CELL FACTORIES. 2018;17(1): 12.Background: Members of the genus Streptomyces are Gram-positive bacteria that are used as important cell factories to produce secondary metabolites and secrete heterologous proteins. They possess some of the largest bacterial genomes and thus proteomes. Understanding their complex proteomes and metabolic regulation will improve any genetic engineering approach. Results: Here, we performed a comprehensive annotation of the subcellular localization of the proteome of Streptomyces lividans TK24 and developed the Subcellular Topology of Polypeptides in Streptomyces database (SToPSdb) to make this information widely accessible. We first introduced a uniform, improved nomenclature that re-annotated the names of similar to 4000 proteins based on functional and structural information. Then protein localization was assigned de novo using prediction tools and edited by manual curation for 7494 proteins, including information for 183 proteins that resulted from a recent genome re-annotation and are not available in current databases. The S. lividans proteome was also linked with those of other model bacterial strains including Streptomyces coelicolor A3(2) and Escherichia coli K-12, based on protein homology, and can be accessed through an open web interface. Finally, experimental data derived from proteomics experiments have been incorporated and provide validation for protein existence or topology for 579 proteins. Proteomics also reveals proteins released from vesicles that bleb off the membrane. All export systems known in S. lividans are also presented and exported proteins assigned export routes, where known. Conclusions: SToPSdb provides an updated and comprehensive protein localization annotation resource for S. lividans and other streptomycetes. It forms the basis for future linking to databases containing experimental data of proteomics, genomics and metabolomics studies for this organism
Proteome Changes during Transition from Human Embryonic to Vascular Progenitor Cells
Human
embryonic stem cells (hESCs) are promising in regenerative
medicine (RM) due to their differentiation plasticity and proliferation
potential. However, a major challenge in RM is the generation of a
vascular system to support nutrient flow to newly synthesized tissues.
Here we refined an existing method to generate tight vessels by differentiating
hESCs in CD34<sup>+</sup> vascular progenitor cells using chemically
defined media and growth conditions. We selectively purified these
cells from CD34<sup>–</sup> outgrowth populations also formed.
To analyze these differentiation processes, we compared the proteomes
of the hESCs with those of the CD34<sup>+</sup> and CD34<sup>–</sup> populations using high resolution mass spectrometry, label-free
quantification, and multivariate analysis. Eighteen protein markers
validate the differentiated phenotypes in immunological assays; nine
of these were also detected by proteomics and show statistically significant
differential abundance. Another 225 proteins show differential abundance
between the three cell types. Sixty-three of these have known functions
in CD34<sup>+</sup> and CD34<sup>–</sup> cells. CD34<sup>+</sup> cells synthesize proteins implicated in endothelial cell differentiation
and smooth muscle formation, which support the bipotent phenotype
of these progenitor cells. CD34<sup>–</sup> cells are more
heterogeneous synthesizing muscular/osteogenic/chondrogenic/adipogenic
lineage markers. The remaining >150 differentially abundant proteins
in CD34<sup>+</sup> or CD34<sup>–</sup> cells raise testable
hypotheses for future studies to probe vascular morphogenesis
Proteome Changes during Transition from Human Embryonic to Vascular Progenitor Cells
Human
embryonic stem cells (hESCs) are promising in regenerative
medicine (RM) due to their differentiation plasticity and proliferation
potential. However, a major challenge in RM is the generation of a
vascular system to support nutrient flow to newly synthesized tissues.
Here we refined an existing method to generate tight vessels by differentiating
hESCs in CD34<sup>+</sup> vascular progenitor cells using chemically
defined media and growth conditions. We selectively purified these
cells from CD34<sup>–</sup> outgrowth populations also formed.
To analyze these differentiation processes, we compared the proteomes
of the hESCs with those of the CD34<sup>+</sup> and CD34<sup>–</sup> populations using high resolution mass spectrometry, label-free
quantification, and multivariate analysis. Eighteen protein markers
validate the differentiated phenotypes in immunological assays; nine
of these were also detected by proteomics and show statistically significant
differential abundance. Another 225 proteins show differential abundance
between the three cell types. Sixty-three of these have known functions
in CD34<sup>+</sup> and CD34<sup>–</sup> cells. CD34<sup>+</sup> cells synthesize proteins implicated in endothelial cell differentiation
and smooth muscle formation, which support the bipotent phenotype
of these progenitor cells. CD34<sup>–</sup> cells are more
heterogeneous synthesizing muscular/osteogenic/chondrogenic/adipogenic
lineage markers. The remaining >150 differentially abundant proteins
in CD34<sup>+</sup> or CD34<sup>–</sup> cells raise testable
hypotheses for future studies to probe vascular morphogenesis
‘Suicide rates in Crete, Greece during the economic crisis: the effect of age, gender, unemployment and mental health service provision’
Proteome changes during transition from human embryonic to vascular progenitor cells
Summarization: Human embryonic stem cells (hESCs) are promising in regenerative medicine (RM) due to their differentiation plasticity and proliferation potential. However, a major challenge in RM is the generation of a vascular system to support nutrient flow to newly synthesized tissues. Here we refined an existing method to generate tight vessels by differentiating hESCs in CD34+ vascular progenitor cells using chemically defined media and growth conditions. We selectively purified these cells from CD34- outgrowth populations also formed. To analyze these differentiation processes, we compared the proteomes of the hESCs with those of the CD34+ and CD34- populations using high resolution mass spectrometry, label-free quantification, and multivariate analysis. Eighteen protein markers validate the differentiated phenotypes in immunological assays; nine of these were also detected by proteomics and show statistically significant differential abundance. Another 225 proteins show differential abundance between the three cell types. Sixty-three of these have known functions in CD34+ and CD34- cells. CD34+ cells synthesize proteins implicated in endothelial cell differentiation and smooth muscle formation, which support the bipotent phenotype of these progenitor cells. CD34- cells are more heterogeneous synthesizing muscular/osteogenic/chondrogenic/adipogenic lineage markers. The remaining >150 differentially abundant proteins in CD34+ or CD34- cells raise testable hypotheses for future studies to probe vascular morphogenesis.Presented on: Journal of Proteome Researc