31 results on '"Triantaphyllidou IE"'
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2. Pre-treatment gelatinases' serum levels and post-treatment changes in laryngeal cancer patients
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Tsiropoulos G, Papadas T, Triantaphyllidou Ie, Naxakis S, Konstantinos Markou, Triaridis S, Vital I, Goumas P, and Vynios D
- Subjects
Original Article - Abstract
Laryngeal cancer, especially in the advanced stages, is a highly devastating disease, characterized by increased invasiveness and high rates of metastasis. Gelatinases A and B (MMP-2 and -9 respectively) are of particular interest due to their contribution to various stages of carcinogenesis. There is a growing body of evidence with regard to the prognostic value of certain MMPs and their possible role as tumour markers.To identify the pattern of alteration of serum gelatinases A and B in patients with laryngeal cancer following treatment, and a possible correlation with various clinicopathological parameters.Forty nine patients were included in this study. Pre-treatment and post-treatment serum samples were collected and processed by gelatin zymography and western blotting.Only the latent forms of MMP-2 and -9 were identified. Both gelatinases were increased in the serum of laryngeal cancer patients compared to healthy individuals. Patients with supraglottic tumours and active smokers had significantly higher pre-treatment levels of proMMP-2 than patients with glottic tumours (p0.05) and ex-smokers (p0.05), respectively. Patients with primary disease and patients with lymph node involvement showed lower serum proMMP-9 pre-treatment levels than patients with recurrence (p0.05) and patients without neck disease (p0.1), respectively. During the follow-up period the proMMP-2 serum levels increased significantly in the first ten to fifteen days after treatment, gradually decreasing over the following months. The proMMP-9 serum levels showed a gradual decrease after treatment, which was statistically significant (p0.05).The post-treatment alteration pattern of proMMP-9 serum levels shows a possible role of this molecule as a tumour marker in laryngeal cancer. Further research is necessary to clarify the contribution of both gelatinases to the disease progress and determine their role as prognostic factors and tumour markers.
3. Insights on bacteria inactivation in water by cold plasma: Effect of water matrix and pulsed plasmas waveform on physicochemical water properties, species formation and inactivation efficiency of Escherichia coli.
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Triantaphyllidou IE and Aggelopoulos CA
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This study investigates the inactivation of Escherichia coli (E. coli) using pulsed dielectric barrier discharges (DBDs) powered by high-voltage nanosecond and/or microsecond pulses to establish optimal operational conditions. The effects of pulse voltage waveform and water matrix (distilled vs. tap water) were evaluated in terms of inactivation efficiency and energy consumption, along with the generation of reactive oxygen and nitrogen species (RONS). Complete E. coli inactivation (9-log CFU/ml) in distilled water was achieved within 20 min of nanopulsed-DBD treatment, coinciding with rapid acidification, while in tap water, 90 min was required for complete inactivation. Interestingly, at treatment times with similar pH levels between water types, E. coli inactivation was more effective in tap water. Ozone concentrations showed the most significant difference, being ∼6 times higher in distilled water (10.3 mg/L) than in tap water (1.7 mg/L). Although distilled and tap water had similar concentrations of short- and long-lived plasma species, the differing inactivation efficiencies indicate a synergistic effect between pH reduction and reactive species in impairing E. coli functionality. Micropulsed-DBD led to increased concentration of plasma species, faster acidification and inactivation in tap water (complete inactivation within 8 min), but at significantly higher electrical energy per order (56.9 kWh/m
3 compared to 17.4 kWh/m3 for nanopulsed-DBD). The lowest energy per order was recorded for nanopulsed-DBD in distilled water, at 3.8 kWh/m³, highlighting pulsed-DBD plasma as a safe and energy-efficient method for water disinfection. This study offers valuable insights into using an innovative, sustainable plasma-based approach for bacterial inactivation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)- Published
- 2024
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4. Mechanisms of Individual and Simultaneous Adsorption of Antibiotics and Dyes onto Halloysite Nanoclay and Regeneration of Saturated Adsorbent via Cold Plasma Bubbling.
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Giannoulia S, Triantaphyllidou IE, Tekerlekopoulou AG, and Aggelopoulos CA
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Halloysite nanoclay (HNC) was examined as an adsorbent for the individual and simultaneous removal of antibiotic enrofloxacin (ENRO) and methylene blue (MB) from aqueous solutions, alongside its regeneration via cold atmospheric plasma (CAP) bubbling. Initially, batch kinetics and isotherm studies were carried out, while the effect of several parameters was evaluated. Both ENRO and MB adsorption onto HNC was better described by Langmuir model, with its maximum adsorption capacity being 34.80 and 27.66 mg/g, respectively. A Pseudo-second order model fitted the experimental data satisfactorily, suggesting chemisorption (through electrostatic interactions) as the prevailing adsorption mechanism, whereas adsorption was also controlled by film diffusion. In the binary system, the presence of MB seemed to act antagonistically to the adsorption of ENRO. The saturated adsorbent was regenerated inside a CAP microbubble reactor and its adsorption capacity was re-tested by applying new adsorption cycles. CAP bubbling was able to efficiently regenerate saturated HNC with low energy requirements (16.67 Wh/g-adsorbent) in contrast to Fenton oxidation. Most importantly, the enhanced adsorption capacity of the CAP-regenerated HNC (compared to raw HNC), when applied in new adsorption cycles, indicated its activation during the regeneration process. The present study provides a green, sustainable and highly effective alternative for water remediation where pharmaceutical and dyes co-exist.
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- 2023
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5. Advanced Collagen-Based Composites as Fertilizers Obtained by Recycling Lime Pelts Waste Resulted during Leather Manufacture.
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Stefan DS, Manea-Saghin AM, Triantaphyllidou IE, Tzoumani I, and Meghea I
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Recent trends in ecological agriculture practices are focused on finding optimal solutions for reuse and recycling of pelt waste from tannery industry. In this context, new collagen-based hydrogels with NPK nutrients encapsulated have been functionalized with synthetic and natural additives, including starch and dolomite, to be used as composite fertilizers. Possible interaction mechanisms are presented in case of each synthetic or natural additive, ranging from strong linkages as a result of esterification reactions until hydrogen bonds and ionic valences. Such interactions are responsible for nutrient release towards soil and plants. These fertilizers have been adequately characterized for their physical chemical and biochemical properties, including nutrient content, and tested on three Greek poor soils and one Romanian normal soil samples. A series of agrochemical tests have been developed by evaluation of uptake and leaching of nutrients on mixtures of sand and soils. It was observed that the clay soil exhibits a higher adsorption capacity than the loam soil for most of nutrients leached from the composite fertilizers tested, with this being correlated with a slower control release towards cultivated plants, thus assuring efficiency of these collagen-based composite fertilizers. The most significant effect was obtained in the case of collagen-based fertilizer functionalized with starch.
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- 2022
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6. Using raw and thermally modified fibrous clay minerals as low concentration NH 4 + -N adsorbents.
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Lazaratou CV, Triantaphyllidou IE, Pantelidis I, Chalkias DA, Kakogiannis G, Vayenas DV, and Papoulis D
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- Adsorption, Clay, Hydrogen-Ion Concentration, Kinetics, Minerals, Water Pollutants, Chemical analysis, Water Purification methods
- Abstract
Raw and modified fibrous clay minerals palygorskite (Pal) and sepiolite (Sep) were tested for their ability to remove ammonium from ammonium polluted water. Palygorskite and sepiolite underwent thermal treatment at 400°C (T-Pal and T-Sep respectively). Raw and thermally treated samples were characterized using XRD, SEM, BET, FTIR, TGA, zeta potential, and XRF. The techniques verified the effect of thermal treatment on sample structures and the enhancement of negative charge. Both raw and thermally activated materials were applied in batch kinetic experiments, and found to be efficient adsorbents in their raw forms, since Pal and Sep achieved 60 and 80% NH
4 + -N removal respectively within 20 min of contact for initial NH4 + -N concentration of 4 mg/L. Similar removal rates were gained for other concentrations representative of contaminated aquifers that were examined, ranging from 1 to 8 mg/L. Results for the modified T-Pal and T-Sep minerals showed up to 20% higher removal rate. Saturation tests indicated the positive effect of thermal treatment on the minerals since T-Pal and T-Sep removal efficiency reached 85% and remained stable for 24 h. However, competitive ions in real water samples can influence the NH4 + -N removal efficiency of the examined samples. At almost all the examined samples, the nonlinear Freundlich isotherm and linear pseudo-second kinetic models showed better fitted all examined samples thus indicating heterogeneous chemisorption., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)- Published
- 2022
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7. Pilot-scale hybrid system combining hydrodynamic cavitation and sedimentation for the decolorization of industrial inks and printing ink wastewater.
- Author
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Zampeta C, Bertaki K, Triantaphyllidou IE, Frontistis Z, Koutsoukos PG, and Vayenas DV
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- Hydrodynamics, Hydrogen Peroxide, Printing, Three-Dimensional, Ink, Wastewater
- Abstract
A pilot-scale hydrodynamic cavitation (HC) system followed by sedimentation (SED) was used for the decolorization of 5 industrial-grade inks, a fluid containing a mixture of the five industrial grade inks (MIX) and printing ink wastewater (PIW). The pilot scale HC reactor combines a Venturi tube with a 31 holes orifice plate accommodated in the vena-contracta of Venturi. The study aimed to define optimal operating conditions, i.e., hydrogen peroxide concentration (H
2 O2 ), pH and combined HC/SED treatment time, to achieve decolorization and reduce HC operation time. Under the optimal conditions at the proposed HC/SED system, color removal reached 92%, 91%, 90%,98% and 90%, for black, red, yellow, cyan, and green ink respectively (at pH 8 without H2 O2 addition). In the same system, color removal for PIW was 92%, whereas for MIX decolorization reached more than 90% for all the wavelengths in the selected spectrum 300-700 nm at HC/SED system (at pH 8 and 1 g L-1 hydrogen peroxide). The suspended particles were characterized by measurements of the particle size distribution and of the respective zeta potential. The equivalent cavitation yields, electric energy consumption and operating costs were calculated. The present work's results suggested that HC combined with sedimentation has a great potential for real applications and is superior compared to other technologies (i.e., H2 O2 alone, sedimentation alone or even HC with or without H2 O)., (Copyright © 2021 Elsevier Ltd. All rights reserved.)- Published
- 2022
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8. Treatment of real industrial-grade dye solutions and printing ink wastewater using a novel pilot-scale hydrodynamic cavitation reactor.
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Zampeta C, Bertaki K, Triantaphyllidou IE, Frontistis Z, and Vayenas DV
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- Coloring Agents, Hydrogen Peroxide, Hydrogen-Ion Concentration, Ink, Hydrodynamics, Wastewater
- Abstract
A novel pilot-scale hydrodynamic cavitation (HC) reactor was used to decolorize industrial-grade dye solutions and printing ink wastewater (PIW). The effect of the orifice plate geometry (1 hole plate of 1 mm and 2 mm in diameter, 31 holes of 1 mm and 2 mm in diameter, 62 holes of 1 mm and 2 mm in diameter), inlet pressure (4, 5 bar), initial dye concentration (0.3 and 0.6 OD), and the synergistic effect of HC and hydrogen peroxide concentration (0.0, 0.5, 1.0, 2.0 g/L) were investigated. The results showed that the highest color removal was obtained using 31 holes orifice plate of 2 mm holes' diameter, at 4 bar inlet pressure. Furthermore, although HC could not degrade completely all the industrial-grade dyes, efficiency was enhanced in the presence of H
2 O2 . The optimum concentration of hydrogen peroxide was 1.0 g/L regardless of the initial concentration of the dyes studied. Under optimum operating conditions, color removal reached up to 68% for black, 39% for red, 43% for yellow, 55% for green, and 51% for cyan dye, while color removal in the PIW reached only 15%. The black dye solution presented almost 100% COD removal, while 38%, 25%, 67%, and 78% COD removal values were obtained for the red, yellow, cyan and green dyes, respectively. 55% COD removal was recorded from the PIW. Concerning cavitation yields, black, red, yellow, green, cyan dye yields reached 2.5E(-7), 1.1E(-7), 1.5E(-7), 2.0E(-7), 1.7E(-7) OD⋅L/J, respectively, while PIW yield was 6.3E(-8) OD⋅L/J. The present study demonstrates that HC combined with green oxidants such as hydrogen peroxide could be an alternative treatment approach for real industrial wastewater streams. However, a combination with a post-treatment method should be applied to maximize both color and COD removal., (Copyright © 2021 Elsevier Ltd. All rights reserved.)- Published
- 2021
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9. Combined electrocoagulation and electrochemical oxidation treatment for groundwater denitrification.
- Author
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Benekos AK, Tsigara M, Zacharakis S, Triantaphyllidou IE, Tekerlekopoulou AG, Katsaounis A, and Vayenas DV
- Subjects
- Denitrification, Electrocoagulation, Electrodes, Nitrates, Groundwater, Water Pollutants, Chemical
- Abstract
Electrocoagulation (EC) with an aluminum electrode arrangement as anode-cathode was applied to denitrify groundwater and electrooxidation (EO) was examined as a post-treatment step to remove the produced by-products. Initially, EC experiments were performed under batch operating mode using artificially-polluted tap water to investigate the effects of initial pH (5.5, 7.5, 8.5), initial NO
3 - -N concentration (25, 35, 45, 55 mg L-1 ) and applied current density (10, 20 mA cm-2 ) on process efficiency. The effect of initial solution pH on ammonium cation concentration was also investigated as their generation (as a by-product) is the main drawback preventing wide-scale application of these treatment processes. Experimental results revealed high nitrate removal percentages (up to 96.3%) for initial pH 7.5 and all initial concentrations and current densities, while the final ammonium concentrations ranged between 5.3 and 9.2 mg NH4 + -N L-1 (for initial NO3 - -N of 25 mg L-1 ). Therefore, EO was examined to oxidize the ammonium cations to nitrogen gas on iridium oxide coated titanium electrodes (IrO2 /Ti) anode surface. The effects of cathode material (aluminum, stainless steel), total current density and anode surface area (3.3-30 mA cm-2 and 12-36 cm2 , respectively) were investigated, and lead to NH4 + -N percentage removals of between 25% (10 mA cm-2 , 12 cm2 ) and 100% (30 mA cm-2 , 24 cm2 ) for an initial NH4 + -N concentration of 10 mg L-1 . The optimum EC (20 mA cm-2 , natural initial pH 7.5-7.8) and EO parameters (30 mA cm-2 , 24 cm2 surface area anode, Al cathode) were combined into a hybrid system to treat two real nitrate-polluted groundwaters with initial NO3 - -N concentrations of 25 and 75 mg L-1 . Results revealed that the proposed hybrid treatment system can be used to efficiently remove nitrate from groundwaters., (Copyright © 2021 Elsevier Ltd. All rights reserved.)- Published
- 2021
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10. Simultaneous removal of ammonium nitrogen, dissolved chemical oxygen demand and color from sanitary landfill leachate using natural zeolite.
- Author
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Genethliou C, Triantaphyllidou IE, Giannakis D, Papayianni M, Sygellou L, Tekerlekopoulou AG, Koutsoukos P, and Vayenas DV
- Abstract
In this study, natural zeolite with maximum adsorption capacity of 3.59 mg g
-1 was used for the simultaneous removal of ammonium nitrogen (NH4 + -N), dissolved chemical oxygen demand (d-COD) and color from raw sanitary landfill leachate (SLL). Saturation, desorption and regeneration tests of zeolite were performed. Optimum adsorption conditions were found for particle size 0.930 µm, stirring rate of 1.18 m s-1 , zeolite dosage of 133 g L-1 and pH 8. NH4 + -N removal efficiency reached 51.63 ± 0.80% within 2.5 min of contact. NH4 + -N adsorption follows mostly the linear pseudo-second order model, with intra-particle diffusion. NH4 + -N desorption follows the linear pseudo-second order model. Adsorption data fitted to the Temkin Isotherm in linear and nonlinear forms. Saturation tests showed that zeolite can be efficiently used in three successive adsorption cycles. NH4 + -N release from the saturated zeolite was not completely reversible, suggesting that the zeolite may be used as slow ΝΗ4 + -Ν releasing fertilizer and an attractive low cost material for the treatment of SLL. NH4 + -N removal with the regenerated zeolite exceeded 40% of the initial concentration in the fluid within 2.5 min. SEM analysis showed significant changes through saturation and regeneration. XPS revealed that adsorption of ΝΗ4 + -Ν to the zeolite was accompanied by ion exchange., (Copyright © 2020 Elsevier B.V. All rights reserved.)- Published
- 2021
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11. Collagen-Based Hydrogels Composites from Hide Waste to Produce Smart Fertilizers.
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Stefan DS, Zainescu G, Manea-Saghin AM, Triantaphyllidou IE, Tzoumani I, Tatoulis TI, Syriopoulos GΤ, and Meghea A
- Abstract
The study aims at reusing and recycling the protein hide waste from the leather industry in ecological conditions by elaborating an innovative procedure in order to obtain a collagen matrix functionalized with nitrogen, phosphorus, and potassium (NPK) nutrients to be used for preparing smart fertilizers. This is an interdisciplinary approach, as it starts from hide waste raw material as a critical industrial waste, which is then subjected to several technological steps by selection of optimal processing parameters, followed by product fabrication at the laboratory, and next scales to the industrial pilot plant to obtain novel agro-hydrogels. In this context, the technology scheme for collagen hydrolysate with encapsulated nutrients was proposed and the process parameters were optimized by functionalization of agro-hydrogels with various natural and synthetic polymers, such as polyacrylamide, poly(sodium 4-styrenesulfonate-co-glycidyl methacrylate) copolymer, starch or dolomite. Based on the laboratory experiments, a pilot plant was constructed and tested. Taking as reference the collagen hydrolysate with encapsulated nutrients, the new fertilizers were adequately characterized by chemical analysis, determination of biodegradability and the degree of release of oxidable compounds in water. Based on the biodegradation mechanism and kinetic analysis of oxidable compounds release, adequate arguments are evidenced to demonstrate that these fertilizers can be applied for amendment of poor agricultural soils.
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- 2020
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12. The Complex Interplay Between Extracellular Matrix and Cells in Tissues.
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Manou D, Caon I, Bouris P, Triantaphyllidou IE, Giaroni C, Passi A, Karamanos NK, Vigetti D, and Theocharis AD
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- Animals, Extracellular Matrix Proteins metabolism, Humans, Hyaluronic Acid metabolism, Neoplasms metabolism, Autophagy, Cell Communication, Extracellular Matrix metabolism, Neovascularization, Physiologic
- Abstract
Extracellular matrix (ECM) maintains the structural integrity of tissues and regulates cell and tissue functions. ECM is comprised of fibrillar proteins, proteoglycans (PGs), glycosaminoglycans, and glycoproteins, creating a heterogeneous but well-orchestrated network. This network communicates with resident cells via cell-surface receptors. In particular, integrins, CD44, discoidin domain receptors, and cell-surface PGs and additionally voltage-gated ion channels can interact with ECM components, regulating signaling cascades as well as cytoskeleton configuration. The interplay of ECM with recipient cells is enriched by the extracellular vesicles, as they accommodate ECM, signaling, and cytoskeleton molecules in their cargo. Along with the numerous biological properties that ECM can modify, autophagy and angiogenesis, which are critical for tissue homeostasis, are included. Throughout development and disease onset and progression, ECM endures rearrangement to fulfill cellular requirements. The main responsible molecules for tissue remodeling are ECM-degrading enzymes including matrix metalloproteinases, plasminogen activators, cathepsins, and hyaluronidases, which can modify the ECM structure and function in a dynamic mode. A brief summary of the complex interplay between ECM macromolecules and cells in tissues and the contribution of ECM in tissue homeostasis and diseases is given.
- Published
- 2019
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13. High lipid accumulation in Yarrowia lipolytica cultivated under double limitation of nitrogen and magnesium.
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Bellou S, Triantaphyllidou IE, Mizerakis P, and Aggelis G
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- ATP Citrate (pro-S)-Lyase metabolism, Biomass, Bioreactors, Citric Acid metabolism, Enzyme Activation, Isocitrate Dehydrogenase metabolism, Lipid Metabolism, Lipids biosynthesis, Magnesium chemistry, Nitrogen chemistry, Oxidation-Reduction, Pentose Phosphate Pathway, Yarrowia genetics, Lipids chemistry, Magnesium metabolism, Nitrogen metabolism, Yarrowia metabolism
- Abstract
Yarrowia lipolytica cultivated under double nitrogen and magnesium limitation, but not under single nitrogen or single magnesium limitation, produced 12.2g/l biomass containing 47.5% lipids, which corresponds to a lipid production 5.8g/l. These yields are the higher described in the literature for wild strains of Y. lipolytica. Transcription of ACL1 and ACL2, encoding for ATP-citrate lyase (ATP:CL) was observed even under non-oleaginous conditions but high activity of ATP:CL was only detected under oleaginous conditions induced by low or zero activity of NAD(+) dependent isocitrate dehydrogenase. The low activity of malic enzyme (ME), a NADPH donor in typical oleaginous microorganisms, indicated that ME may not be implicated in lipid biosynthesis in this yeast, and NADPH may be provided by the pentose phosphate pathway (PPP). These findings underline the essential role of magnesium in lipogenesis, which is currently quite unexplored. The presence of organic nitrogen in low concentrations during lipogenesis was also required, and this peculiarity was probably related with the PPP functioning, being the NADPH donor of lipogenic machinery in Y. lipolytica., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
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14. Newly isolated yeasts from Tunisian microhabitats: Lipid accumulation and fatty acid composition.
- Author
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Arous F, Azabou S, Triantaphyllidou IE, Aggelis G, Jaouani A, Nasri M, and Mechichi T
- Abstract
Newly isolated yeasts from different Tunisian microhabitats, such as soil, milk, olive brine, vinegar, and from olive mill wastewater-contaminated biotopes were extensively studied for their biochemical arsenal and morphological features, i.e. cell, ascospore, and lipid body morphology. All strains were classified into the Ascomycota phylum. However, they showed great functional diversity, including different morphological and biochemical features, lipid production ability, and fatty acid profiles. Accordingly, the strains were placed in three different groups: Group I, which includes Candida species; Group II ( Pichia and related); and Group III ( Kluyveromyces marxianus strain CC1). Group I and II were characterized by a high percentage of oleic acid (41.6-65.3% of total lipids) while in Group III, linoleic acid was the major fatty acid (37.2%). Members of Group I and II were further grouped into subgroups according to their fatty acid composition. Among the newly isolated strains, Pichia etchellsii BM1 was able to accumulate around 25% wt/wt lipid per dry cell mass and thus characterized as oleaginous. Some other strains, such as Candida metapsilosis strain EL2, C. parapsilosis strain LV2, C. pararugosa strain BM24, and K. marxianus strain CC1, which are able to produce extracellular lipases, may be of interest for specific environmental applications and/or for the production of novel lipases., (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2016
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15. Microbial oils as food additives: recent approaches for improving microbial oil production and its polyunsaturated fatty acid content.
- Author
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Bellou S, Triantaphyllidou IE, Aggeli D, Elazzazy AM, Baeshen MN, and Aggelis G
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- Animals, Fatty Acids metabolism, Fatty Acids, Unsaturated metabolism, Food Additives, Humans, Lipid Metabolism, Microbiota, Oils chemistry, Oils metabolism
- Abstract
In this short review, we summarize the latest research in the production of polyunsaturated microbial oils that are of interest in food technology. The current research targets the productivity of oleaginous microorganisms, as well as the biosynthesis of particular polyunsaturated fatty acids (PUFAs). The most important efforts target the efficiency of the oleaginous machinery, via overexpression of key-enzymes involved in lipid biosynthesis, as well as the minimization of lipid degradation, by repressing genes involved in the β-oxidation pathway. The production of specific PUFAs is approached by homologous or heterologous expression of specific desaturases and elongases involved in PUFA biosynthesis in oleaginous microorganisms. New perspectives, such as the production of triacylglycerols of specific structure and the employment of adaptive experimental evolution for creating robust oleaginous strains able to produce PUFAs are also discussed., (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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16. Increased β-glucuronidase activity in bronchoalveolar lavage fluid of children with bacterial lung infection: A case-control study.
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Panagiotopoulou EC, Fouzas S, Douros K, Triantaphyllidou IE, Malavaki C, Priftis KN, Karamanos NK, and Anthracopoulos MB
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- Adolescent, Area Under Curve, Bacterial Infections diagnosis, Biomarkers analysis, Bronchoalveolar Lavage Fluid cytology, Bronchoalveolar Lavage Fluid microbiology, Case-Control Studies, Child, Child, Preschool, Female, Humans, Inflammation metabolism, Inflammation microbiology, Interleukin-8 analysis, Leukocyte Count, Lung pathology, Lung Diseases microbiology, Male, Pancreatic Elastase analysis, ROC Curve, Respiratory Tract Infections diagnosis, Respiratory Tract Infections microbiology, Tumor Necrosis Factor-alpha analysis, Bacterial Infections enzymology, Bronchoalveolar Lavage Fluid chemistry, Glucuronidase metabolism, Lung Diseases enzymology, Neutrophils, Respiratory Tract Infections enzymology
- Abstract
Background and Objective: β-Glucuronidase is a lysosomal enzyme released into the extracellular fluid during inflammation. Increased β-glucuronidase activity in the cerebrospinal and peritoneal fluid has been shown to be a useful marker of bacterial inflammation. We explored the role of β-glucuronidase in the detection of bacterial infection in bronchoalveolar lavage fluid (BALF) of paediatric patients., Methods: In this case-control study, % polymorphonuclear cell count (PMN%), β-glucuronidase activity, interleukin-8 (IL-8), tumour necrosis factor-α (TNF-α) and elastase were measured in culture-positive (≥10(4) cfu/mL, C+) and -negative (C-) BALF samples obtained from children., Results: A total of 92 BALF samples were analysed. The median β-glucuronidase activity (measured in nanomoles of 4-methylumbelliferone (4-MU)/mL BALF/h) was 246.4 in C+ (interquartile range: 71.2-751) and 21.9 in C- (4.0-40.8) (P < 0.001). The levels of TNF-α and IL-8 were increased in C+ as compared with C- (5.4 (1.7-12.6) vs 0.7 (0.2-6.2) pg/mL, P < 0.001 and 288 (76-4300) vs 287 (89-1566) pg/mL, P = 0.042, respectively). Elastase level and PMN% did not differ significantly (50 (21-149) vs 26 (15-59) ng/mL, P = 0.051 and 20 (9-40) vs 18 (9-34) %, P = 0.674, respectively). The area under the curve of β-glucuronidase activity (0.856, 95% confidence interval (CI): 0.767-0.920) was higher than that of TNF-α (0.718; 95% CI: 0.614-0.806; P = 0.040), IL-8 (0.623; 95% CI: 0.516-0.722; P = 0.001), elastase (0.645; 95% CI: 0.514-0.761; P = 0.008) and PMN% (0.526; 95 % CI: 0.418-0.632; P < 0.001)., Conclusions: This study demonstrates a significant increase of β-glucuronidase activity in BALF of children with culture-positive bacterial inflammation. In our population β-glucuronidase activity showed superior predictive ability for bacterial lung infection than other markers of inflammation., (© 2015 Asian Pacific Society of Respirology.)
- Published
- 2015
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17. Feasibility of raw glycerol conversion into single cell oil by zygomycetes under non-aseptic conditions.
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Moustogianni A, Bellou S, Triantaphyllidou IE, and Aggelis G
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- Bacteria growth & development, Bioreactors, Culture Media chemistry, Thymus Plant chemistry, Glycerol metabolism, Mucorales growth & development, Mucorales metabolism, Plant Oils metabolism
- Abstract
The use of plant oils as feedstock for the biodiesel manufacture has many drawbacks, thus, the interest has turned to single cell oil (SCO) as an alternative. However, the production of SCO is still too expensive, mainly due to the low oil productivity and the high cost of medium sterilization required. In this work raw glycerol was converted into SCO by oleaginous Zygomycetes under non-aseptic conditions on selective (i.e., containing essential oils and/or antibiotics) nitrogen limited media. The obtained data showed that although bacterial populations inhibited the fungal growth, lipid accumulation remained unaffected by the presence of bacteria in the growth medium compared to control experiments (conducted under aseptic conditions). Therefore, a two-stage process was developed in which growth was performed under aseptic conditions (1st stage) followed by lipid accumulation performed under non-aseptic conditions (2nd stage) in the presence of thyme essential oil as an antibacterial agent. Large amounts of lipids were accumulated inside the mycelia, yielding around 13% wt/wt of oil per glycerol consumed., (© 2014 Wiley Periodicals, Inc.)
- Published
- 2015
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18. Morphological and metabolic shifts of Yarrowia lipolytica induced by alteration of the dissolved oxygen concentration in the growth environment.
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Bellou S, Makri A, Triantaphyllidou IE, Papanikolaou S, and Aggelis G
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- Carbon metabolism, Culture Media chemistry, Gene Expression Regulation, Fungal drug effects, Glucose metabolism, Glycerol metabolism, Hyphae cytology, Hyphae growth & development, Hyphae metabolism, Nitrogen metabolism, Olive Oil, Plant Oils metabolism, Yarrowia growth & development, Oxygen metabolism, Yarrowia cytology, Yarrowia metabolism
- Abstract
Yarrowia lipolytica, an ascomycete with biotechnological potential, is able to form either yeast cells or hyphae and pseudohyphae in response to environmental conditions. This study shows that the morphology of Y. lipolytica, cultivated in batch cultures on hydrophilic (glucose and glycerol) and hydrophobic (olive oil) media, was not affected by the nature of the carbon source, nor by the nature or the concentration of the nitrogen source. By contrast, dissolved oxygen concentration (DOC) should be considered as the major factor affecting yeast morphology. Specifically, when growth occurred at low or zero DOC the mycelial and/or pseudomycelial forms predominated over the yeast form independently of the carbon and nitrogen sources used. Experimental data obtained from a continuous culture of Y. lipolytica on glycerol, being used as carbon and energy source, demonstrated that the mycelium-to-yeast form transition occurs when DOC increases from 0.1 to 1.5 mg l(-1). DOC also affected the yeast physiology, as the activity of enzymes implicated in lipid biosynthesis (i.e. ATP-citrate lyase, malic enzyme) was upregulated at high DOC whereas the activity of enzymes implicated in glycerol assimilation (such as glycerol dehydrogenase and kinase) remained fundamentally unaffected in the cell-free extract.
- Published
- 2014
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19. Pre-treatment gelatinases' serum levels and post-treatment changes in laryngeal cancer patients.
- Author
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Tsiropoulos G, Papadas T, Triantaphyllidou Ie, Naxakis S, Markou K, Triaridis S, Vital I, Goumas P, and Vynios D
- Abstract
Introduction: Laryngeal cancer, especially in the advanced stages, is a highly devastating disease, characterized by increased invasiveness and high rates of metastasis. Gelatinases A and B (MMP-2 and -9 respectively) are of particular interest due to their contribution to various stages of carcinogenesis. There is a growing body of evidence with regard to the prognostic value of certain MMPs and their possible role as tumour markers., Aim: To identify the pattern of alteration of serum gelatinases A and B in patients with laryngeal cancer following treatment, and a possible correlation with various clinicopathological parameters., Materials and Methods: Forty nine patients were included in this study. Pre-treatment and post-treatment serum samples were collected and processed by gelatin zymography and western blotting., Results: Only the latent forms of MMP-2 and -9 were identified. Both gelatinases were increased in the serum of laryngeal cancer patients compared to healthy individuals. Patients with supraglottic tumours and active smokers had significantly higher pre-treatment levels of proMMP-2 than patients with glottic tumours (p < 0.05) and ex-smokers (p < 0.05), respectively. Patients with primary disease and patients with lymph node involvement showed lower serum proMMP-9 pre-treatment levels than patients with recurrence (p < 0.05) and patients without neck disease (p < 0.1), respectively. During the follow-up period the proMMP-2 serum levels increased significantly in the first ten to fifteen days after treatment, gradually decreasing over the following months. The proMMP-9 serum levels showed a gradual decrease after treatment, which was statistically significant (p<0.05)., Conclusions: The post-treatment alteration pattern of proMMP-9 serum levels shows a possible role of this molecule as a tumour marker in laryngeal cancer. Further research is necessary to clarify the contribution of both gelatinases to the disease progress and determine their role as prognostic factors and tumour markers.
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- 2013
20. Expression and distribution of aggrecanases in human larynx: ADAMTS-5/aggrecanase-2 is the main aggrecanase in laryngeal carcinoma.
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Filou S, Stylianou M, Triantaphyllidou IE, Papadas T, Mastronikolis NS, Goumas PD, Papachristou DJ, Ravazoula P, Skandalis SS, and Vynios DH
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- ADAMTS1 Protein, ADAMTS4 Protein, ADAMTS5 Protein, Aged, Carcinoma, Squamous Cell enzymology, Carcinoma, Squamous Cell genetics, Carcinoma, Squamous Cell metabolism, Female, Humans, Laryngeal Neoplasms metabolism, Larynx enzymology, Male, Procollagen N-Endopeptidase genetics, Procollagen N-Endopeptidase metabolism, Protein Transport, RNA, Messenger genetics, RNA, Messenger metabolism, ADAM Proteins genetics, ADAM Proteins metabolism, Gene Expression Regulation, Neoplastic, Laryngeal Neoplasms enzymology, Laryngeal Neoplasms genetics, Larynx metabolism
- Abstract
Members of the ADAMTS family of proteases degrade proteoglycans and thereby have the potential to alter tissue architecture and regulate cellular functions. Aggrecanases are the main enzymes responsible for aggrecan degradation, due to their specific cleavage pattern. In this study, the expression status, the macromolecular organization and localization of ADAMTS-1, ADAMTS-4/aggrecanase-1 and ADAMTS-5/aggrecanase-2 in human normal larynx and laryngeal squamous cell carcinoma (LSCC) were investigated. On mRNA level, the results showed that ADAMTS-4 was the highest expressed enzyme in normal larynx, whereas ADAMTS-5 was the main aggrecanase in LSCC presenting a stage-related increase up to stage III (8-fold higher expression compared to normal), and thereafter decreased in stage IV. Accordingly, immunohistochemical analysis showed that ADAMTS-5, but not ADAMTS-4, was highly expressed by carcinoma cells. Sequential extraction revealed an altered distribution and organization of multiple molecular forms (latent, activated and fragmented forms) of the enzymes within the cancerous and their corresponding macroscopically normal laryngeal tissues, compared to the normal ones. Importantly, these analyses indicated that critical macromolecular changes occurred from the earliest LSCC stages not only in malignant parts of the tissue but also in areas that were not in proximity to carcinoma cells and appeared otherwise normal. Overall, the results of the present study show that ADAMTS-5/aggrecanase-2 is the main aggrecanase present in laryngeal carcinoma suggesting a critical role for the enzyme in aggrecan degradation and laryngeal tissue destruction during tumor progression., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)
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- 2013
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21. Perturbations in the HDL metabolic pathway predispose to the development of osteoarthritis in mice following long-term exposure to western-type diet.
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Triantaphyllidou IE, Kalyvioti E, Karavia E, Lilis I, Kypreos KE, and Papachristou DJ
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- Animals, Apolipoprotein A-I deficiency, Apolipoprotein A-I genetics, Apolipoprotein A-I metabolism, Body Weight physiology, Causality, Disease Models, Animal, Lecithin Cholesterol Acyltransferase Deficiency metabolism, Lecithin Cholesterol Acyltransferase Deficiency physiopathology, Lipids blood, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, Obesity etiology, Obesity physiopathology, Phosphatidylcholine-Sterol O-Acyltransferase genetics, Phosphatidylcholine-Sterol O-Acyltransferase metabolism, Time Factors, Western World, Diet, High-Fat adverse effects, Lipoproteins, HDL metabolism, Metabolic Networks and Pathways physiology, Obesity metabolism, Osteoarthritis, Knee metabolism, Osteoarthritis, Knee physiopathology
- Abstract
Objective: Recent data suggest that obesity and related metabolic aberrations are associated with osteoarthritis (OA) development, a phenomenon that is attributed at least in part to the consumption of lipid-rich diets. To date, the molecular mechanisms that govern the lipid-OA connection remain largely unknown. Given the important role of high-density lipoprotein (HDL) in plasma and tissue lipid metabolism, the main purpose of the present study was to investigate the role of HDL metabolism in the pathobiology of OA., Methods: We used apolipoprotein A-I (apoA-I)(-/-) mice that lack classical apoA-I containing HDL, LCAT(-/-) mice that have only immature HDL and relatively reduced HDL-cholesterol levels and control C57BL/6 mice. Mice were placed on chow or western-type (WTD) and monitored for 24 weeks. Knee joints were removed and articular cartilage was isolated for further analyses., Results: The LCAT(-/-) mice were significantly more sensitive to the development of diet-induced obesity compared to the C57BL/6 and apoA-I(-/-) mice. Morphological, biochemical and molecular analyses revealed that the LCAT(-/-) obese mice developed OA, while the C57BL/6 mice that were fed WTD did not. Notably, apoA-I(-/-) mice that received WTD also developed OA although their body-weight gain was similar to their wild-type counterparts. Interestingly, bone marrow from LCAT(-/-) and apoA-I(-/-) mice contained significantly increased number of adipocytes, compared to the other groups., Conclusions: Our findings suggest that perturbations in HDL metabolism predispose to OA following chronic insult with WTD and raise the challenging possibility that HDL has a causative relation to OA in patients with metabolic syndrome., (Copyright © 2012 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2013
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22. Presence of hyaluronidase isoforms in nasal polyps.
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Hatziri A, Vynios DH, Panogeorgou T, Bouga H, Triantaphyllidou IE, Naxakis SS, Stathas T, Aletras AJ, Kourousis C, and Mastronikolis NS
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- Blotting, Western, Humans, Hydrogen-Ion Concentration, Isoenzymes analysis, Hyaluronoglucosaminidase analysis, Nasal Polyps enzymology
- Abstract
Background: Nasal polyps are benign lesions originating from the nasal mucosa or paranasal sinuses. The most important etiological factor seems to be increased hydration of epithelium and hyperplasia of the extracellular matrix, which may involve hyaluronan, a high molecular mass extracellular glycosaminoglycan. Degradation of hyaluronan proceeds through the action of specific hyaluronidases., Objective: The aim of the present study was to investigate the hydrodynamic size of hyaluronan and the presence of the various hyaluronidase isoforms in nasal polyps., Methods: Samples of polypoid mucosal tissue and normal nasal mucosa were obtained from twenty patients suffering from nasal polyposis. Zymographic analysis and western blotting were used to detect hyaluronidase activity., Results: The results indicated the presence of hyaluronan of small molecular mass in all samples examined. About one third of it has a mean molecular mass of 240 kDa, exactly that required for the expression of inflammatory response. Laboratory analysis suggested that degradation of hyaluronan occurred through the action of three hyaluronidase isoforms: Hyal-1, Hyal-2 and PH-20., Conclusions: Since hyaluronan fragments of 200-250 kDa induce the expression of inflammatory cytokines, a specific role of hyaluronidases in the development or progression of nasal polyps may be concluded. Therefore, new treatment protocols may be proposed.
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- 2013
23. Apolipoprotein A-I modulates processes associated with diet-induced nonalcoholic fatty liver disease in mice.
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Karavia EA, Papachristou DJ, Liopeta K, Triantaphyllidou IE, Dimitrakopoulos O, and Kypreos KE
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- Adenoviridae genetics, Adiposity drug effects, Animals, Apolipoprotein A-I deficiency, Body Weight drug effects, Calorimetry, Fatty Liver blood, Fatty Liver genetics, Feeding Behavior, Gene Expression Regulation drug effects, Glucose Intolerance complications, Glucose Intolerance genetics, Glucose Intolerance pathology, Insulin pharmacology, Intestinal Mucosa metabolism, Intestines drug effects, Intestines pathology, Kinetics, Lipogenesis drug effects, Lipogenesis genetics, Liver drug effects, Liver metabolism, Liver pathology, Male, Mice, Mice, Inbred C57BL, Non-alcoholic Fatty Liver Disease, Postprandial Period drug effects, Recombination, Genetic drug effects, Recombination, Genetic genetics, Triglycerides blood, Triglycerides metabolism, Apolipoprotein A-I metabolism, Diet, Fatty Liver metabolism, Fatty Liver pathology
- Abstract
Apolipoprotein A-I (apoA-I) is the main protein of high-density lipoprotein (HDL). We investigated the involvement of apoA-I in diet-induced accumulation of triglycerides in hepatocytes and its potential role in the treatment of nonalcoholic fatty liver disease (NAFLD). ApoA-I-deficient (apoA-I(-/-)) mice showed increased diet-induced hepatic triglyceride deposition and disturbed hepatic histology while they exhibited reduced glucose tolerance and insulin sensitivity. Quantification of FASN (fatty acid synthase) [corrected], DGAT-1 (diacylglycerol O-acyltransferase 1), and PPARγ (peroxisome proliferator-activated receptor γ) mRNA expression suggested that the increased hepatic triglyceride content of the apoA-I(-/-) mice was not due to de novo synthesis of triglycerides. Similarly, metabolic profiling did not reveal differences in the energy expenditure between the two mouse groups. However, apoA-I(-/-) mice exhibited enhanced intestinal absorption of dietary triglycerides (3.6 ± 0.5 mg/dL/min for apoA-I(-/-) versus 2.0 ± 0.7 mg/dL/min for C57BL/6 mice, P < 0.05), accelerated clearance of postprandial triglycerides and a reduced rate of hepatic very low density lipoprotein (VLDL) triglyceride secretion (9.8 ± 1.1 mg/dL/min for apoA-I(-/-) versus 12.5 ± 1.3 mg/dL/min for C57BL/6 mice, P < 0.05). In agreement with these findings, adenovirus-mediated gene transfer of apoA-I(Milano) in apoA-I(-/-) mice fed a Western-type diet for 12 wks resulted in a significant reduction in hepatic triglyceride content and an improvement of hepatic histology and architecture. Our data extend the current knowledge on the functions of apoA-I, indicating that in addition to its well-established properties in atheroprotection, it is also an important modulator of processes associated with diet-induced hepatic lipid deposition and NAFLD development in mice. Our findings raise the interesting possibility that expression of therapeutic forms of apoA-I by gene therapy approaches may have a beneficial effect on NAFLD.
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- 2012
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24. Biomechanical and structural changes following the decellularization of bovine pericardial tissues for use as a tissue engineering scaffold.
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Pagoulatou E, Triantaphyllidou IE, Vynios DH, Papachristou DJ, Koletsis E, Deligianni D, and Mavrilas D
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- Animals, Biocompatible Materials, Biomechanical Phenomena, Bioprosthesis, Cattle, Cell Adhesion, Cell Culture Techniques, Cell Movement, Elastic Modulus, Endothelial Cells cytology, Humans, Materials Testing, Pericardium chemistry, Pericardium cytology, Tissue Engineering methods, Tissue Scaffolds chemistry
- Abstract
To achieve natural scaffolds for tissue engineering applications we decellularized bovine pericardial (BP) tissues according to two different protocols: a novel treatment based on Triton(®) X-100 (12 h, 4 °C) (BP1) and a trypsin/EDTA treatment (37 °C, 48 h) (BP2). Results were compared with commercially available acellular xenogeneic biomaterials, Veritas(®) and Collamed(®). Biomechanical characteristics, high (E(h)) and low (E(l)) modulus of elasticity, of the fresh untreated tissue varied with the anatomical direction (apex to base (T) to transverse (L)) (mean ± SDEV): (41.63 ± 14.65-48.12 ± 10.19 MPa and 0.27 ± 0.05-0.30 ± 0.12 MPa respectively). BP1 had no mechanical effect (44.65 ± 19.73-52.67 ± 7.59 MPa and 0.37 ± 0.14-0.37 ± 0.11 MPa, respectively) but BP2 resulted in significant decrease in E(h) and E(l) (20.96 ± 8.17-36.82 ± 3.23 MPa and 0.20 ± 0.06-0.23 ± 0.06 MPa). Hysteresis ratio (h) varied (19-26 % of the loading energy) independently of anatomical direction. Glycosaminoglycans content was unaffected by BP1, while 22 % of chondroitin/dermatan sulphate and 60 % of hyaluronan were removed after BP2 treatment. Endothelial cell adhesion was achieved after 24 h and 3 days cell culture.
- Published
- 2012
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25. Frontotemporal dementia, manifested as schizophrenia, with decreased heterochromatin on chromosome 1.
- Author
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Gourzis P, Skokou M, Polychronopoulos P, Soubasi E, Triantaphyllidou IE, Aravidis C, Sarela AI, and Kosmaidou Z
- Abstract
Introduction. Frontotemporal dementia is a disorder of complex etiology, with genetic components contributing to the disease. The aim of this report is to describe a young patient suffering from frontotemporal dementia, misdiagnosed as schizophrenia, related to a genetic defect on chromosome 1. Case Presentation. A 29-year-old female patient, previously diagnosed as having schizophrenia, was hospitalized with severe behavioural disturbances. She demonstrated severe sexual disinhibition, hyperphagia, lack of motivation, apathy, psychotic symptoms, suicidal thoughts, and cognitive deterioration. Focal atrophy of frontal and anterior temporal structures bilaterally was found on brain MRI, as well as bifrontal hypo perfusion of the brain on SPECT scan. The diagnosis of frontotemporal dementia was made clinically, according to Lund and Manchester groups and Neary diagnostic criteria. Chromosomal analysis was conducted and revealed decrease in length of heterochromatin on the long arm of chromosome 1 (46, XX, 1qh-). Parental karyotypes were normal. Discussion. Frontotemporal dementia, and particularly early-onset cases, can be often misdiagnosed as schizophrenia, with negative impact on case management. Genetic testing could be an aid to the correct diagnosis, which is crucial for optimal patient care.
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- 2012
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26. The chondroitin/dermatan sulfate synthesizing and modifying enzymes in laryngeal cancer: expressional and epigenetic studies.
- Author
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Kalathas D, Triantaphyllidou IE, Mastronikolis NS, Goumas PD, Papadas TA, Tsiropoulos G, and Vynios DH
- Subjects
- Adult, Aged, Antigens, Neoplasm genetics, Antigens, Neoplasm metabolism, Carcinoma, Squamous Cell enzymology, Carcinoma, Squamous Cell metabolism, Case-Control Studies, Chondroitin biosynthesis, DNA-Binding Proteins genetics, DNA-Binding Proteins metabolism, Dermatan Sulfate biosynthesis, Enzymes metabolism, Gene Expression Profiling, Glucuronosyltransferase genetics, Glucuronosyltransferase metabolism, Humans, Laryngeal Neoplasms enzymology, Laryngeal Neoplasms metabolism, Middle Aged, N-Acetylgalactosaminyltransferases genetics, N-Acetylgalactosaminyltransferases metabolism, Neoplasm Proteins genetics, Neoplasm Proteins metabolism, Sulfotransferases genetics, Sulfotransferases metabolism, Carcinoma, Squamous Cell genetics, Chondroitin metabolism, Dermatan Sulfate metabolism, Enzymes genetics, Epigenesis, Genetic physiology, Gene Expression Regulation, Enzymologic, Laryngeal Neoplasms genetics
- Abstract
Background: Significant biochemical changes are observed in glycosaminoglycans in squamous cell laryngeal carcinoma. The most characteristics are in chondroitin/dermatan sulfate fine structure and proportion, which might be due to differential expression of the enzymes involved in their biosynthesis. The aim of the present work was the investigation in expressional and epigenetic level of the enzymes involved in chondroitin/dermatan sulfate biosynthesis in laryngeal cancer., Methods: Tissues subjected to total RNA and DNA isolation, and protein extraction. The techniques used in this study were RT-PCR analysis, western blotting and methylation specific PCR., Results: We identified that many enzymes were expressed in the cancerous specimens intensively. Dermatan sulfate epimerase was expressed exclusively in the cancerous parts and in minor amounts in healthy tissues; in the macroscopically normal samples it was not detected. Furthermore, chondroitin synthase I and chondroitin polymerizing factor were strongly expressed in the cancerous parts compared to the corresponding normal tissues. Sulfotransferases, like chondroitin 6 sulfotransferase 3, were highly expressed mainly in healthy specimens., Conclusions: The study of the various chondroitin/dermatan synthesizing enzymes revealed that they were differentially expressed in cancer, in human laryngeal cartilage, leading to specific chondroitin/dermatan structures which contributed to proteoglycan formation with specific features. The expression of the examined enzymes correlated with the glycosaminoglycan profile observed in previous studies.
- Published
- 2010
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27. A proposed mechanism for the inhibitory effect of the anticancer agent titanocene dichloride on tumour gelatinases and other proteolytic enzymes.
- Author
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Pavlaki M, Debeli K, Triantaphyllidou IE, Klouras N, Giannopoulou E, and Aletras AJ
- Subjects
- Animals, Antineoplastic Agents metabolism, Basement Membrane enzymology, Catalytic Domain, Cattle, Cell Line, Tumor, Collagen metabolism, Gelatin metabolism, Gelatinases chemistry, Humans, Inhibitory Concentration 50, Organometallic Compounds metabolism, Antineoplastic Agents pharmacology, Gelatinases antagonists & inhibitors, Neoplasms enzymology, Organometallic Compounds pharmacology
- Abstract
Titanocene dichloride, the most studied metallocene, exhibits antiproliferative activity in a wide spectrum of murine and human tumours. In this article it is demonstrated that titanocene dichloride inhibits tumour gelatinases in a dose-dependent manner. Substrate saturation experiments and the fact that the IC(50) values were increased in correlation with collagen substrate concentrations indicate that the titanocene dichloride induced inhibition is of a competitive type. Titanocene dichloride also specifically inhibits clostridium collagenase and trypsin, particularly when collagens are used as substrates. Binding experiments demonstrate that cyclopentadiene-Ti(IV) moieties, resulting from titanocene dichloride at physiological pH, are bound mainly to different types of collagens and to a lesser extent to casein or bovine serum albumin, forming soluble and stable adducts. These results indicate that titanocene dichloride behaves as a competitive inhibitor against various proteolytic enzymes by binding to the substrate rather than to the enzyme active site. This property may be responsible for the antiangiogenic effect of titanocene dichloride and additionally contributes to its anticancer action.
- Published
- 2009
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28. Detection, quantification, and glycotyping of prion protein in specifically activated enzyme-linked immunosorbent assay plates.
- Author
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Triantaphyllidou IE, Sklaviadis T, and Vynios DH
- Subjects
- Animals, Antibodies, Monoclonal immunology, Biological Assay, Brain pathology, Cattle, Encephalopathy, Bovine Spongiform metabolism, Endopeptidase K metabolism, Glycosylation, PrPC Proteins analysis, PrPC Proteins chemistry, PrPSc Proteins chemistry, Recombinant Proteins, Sensitivity and Specificity, Tissue Extracts chemistry, Brain Chemistry, Encephalopathy, Bovine Spongiform diagnosis, Enzyme-Linked Immunosorbent Assay methods, PrPSc Proteins analysis
- Abstract
The conversion of a normal glycoprotein, prion protein (PrP(C)), to its abnormal protease-resistant isoform (PrP(Sc)) seems to be one of the main factors underlying the pathogenesis of spongiform encephalopathies. There are many studies indicating that PrP interacts with glycosaminoglycans, and we exploited this interaction to develop a sensitive solid phase assay for detection of both PrP forms. Glycosaminoglycans, such as chondroitin sulfate and heparin, were immobilized by their negative charge to enzyme-linked immunosorbent assay (ELISA) plate wells activated by glutaraldehyde and spermine. PrP in the samples examined (recombinant PrP or tissue homogenate) was allowed to interact with glycans. The interaction of recombinant PrP was more efficient against immobilized chondroitin sulfate of type A, and a linear correlation with concentration was demonstrated. From this curve, the concentration of each one of the PrP isoforms in biological samples can be determined. In addition, and taking into account that glycosylation of prion protein is species specific, we used similarly activated ELISA plate wells to determine different PrP glycoforms. A monoclonal antibody against PrP was immobilized, and PrP present in the samples (brain homogenates) was bound and visualized by various lectins. The most interesting outcome of the study is the differential binding of ricinus communis agglutinin I to the normal and scrapie brain homogenates. Dattura stramonium lectin and wheat germ agglutinin seem to bind almost equally to both samples, and all three have an increased sensitivity to PrP(Sc) after proteinase K digestion.
- Published
- 2006
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29. Advances in the analysis of chondroitin/dermatan sulfate.
- Author
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Stylianou M, Triantaphyllidou IE, and Vynios DH
- Subjects
- Chromatography, Gel, Chromatography, High Pressure Liquid, Chromatography, Ion Exchange, Electrophoresis, Enzyme-Linked Immunosorbent Assay, Immunohistochemistry, Chondroitin Sulfates analysis, Dermatan Sulfate analysis
- Published
- 2006
- Full Text
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30. HPLC identification of oversulphated chondroitin as the major glycosaminoglycan of human tonsils.
- Author
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Triantaphyllidou IE, Mastronikolis NS, Papadas TA, and Vynios DH
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Chromatography, Gel methods, Humans, Chondroitin Sulfates analysis, Chromatography, High Pressure Liquid methods, Glycosaminoglycans analysis, Palatine Tonsil chemistry
- Abstract
The glycosaminoglycans of human nasopharyngeal and palatine tonsils, obtained after surgical dissection due to tonsillitis, were isolated and characterized by means of enzyme susceptibility and HPLC. Chondroitin/dermatan sulphate were the major glycosaminoglycans identified. A large proportion of this glycosaminoglycan was made up of oversulphated structures, namely DeltaDi-di(4,6)S, which were found mainly in invertebrate tissues and in mast cells., (2004 John Wiley & Sons, Ltd.)
- Published
- 2004
- Full Text
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31. Solid phase assays in glycoconjugate research: applications to the analysis of proteoglycans, glycosaminoglycans and metalloproteinases.
- Author
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Ziouti N, Triantaphyllidou IE, Assouti M, Papageorgakopoulou N, Kyriakopoulou D, Anagnostides ST, and Vynios DH
- Subjects
- Enzyme-Linked Immunosorbent Assay, Glycoconjugates physiology, Glycosaminoglycans metabolism, Greece, Humans, Matrix Metalloproteinases metabolism, Methods, Molecular Structure, Proteoglycans physiology, Glycoconjugates chemistry, Glycosaminoglycans chemistry, Matrix Metalloproteinases chemistry, Proteoglycans chemistry
- Abstract
Glycoconjugates are a class of macromolecules consisting of different constituents, one of which is sugar moieties. Glycoconjugates comprise the majority of tissue constituents, both intracellular and extracellular. Extracellular glycoconjugates (glycoproteins and proteoglycans) participate in a wide variety of interactions, through which they maintain tissue integrity. Therefore, their analysis or the study of their possible interactions would give evidence for the state of tissues. Since the amounts of some of the extracellular glycoconjugates are usually low or the amounts of tissue to be examined come from biopsies, specific analytical systems are developed for their study, the most familiar being solid phase assays, which have the advantages of analysis of multiple samples on the same time, cheap instrumentation and high specificity.
- Published
- 2004
- Full Text
- View/download PDF
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