Publications by authors named "Irene-Eva Triantaphyllidou"

15 Publications

  • Page 1 of 1

Using raw and thermally modified fibrous clay minerals as low concentration NH-N adsorbents.

Environ Sci Pollut Res Int 2021 Oct 21. Epub 2021 Oct 21.

Department of Geology, University of Patras, GR-26504, Patras, Greece.

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-N removal respectively within 20 min of contact for initial NH-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 NH-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.
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http://dx.doi.org/10.1007/s11356-021-17107-zDOI Listing
October 2021

Treatment of real industrial-grade dye solutions and printing ink wastewater using a novel pilot-scale hydrodynamic cavitation reactor.

J Environ Manage 2021 Nov 16;297:113301. Epub 2021 Jul 16.

Department of Chemical Engineering, University of Patras, Rio, GR-26504, Patras, Greece; Institute of Chemical Engineering and High Temperature Chemical Processes (FORTH/ ICE-HT), Stadiou Str., Platani, GR-26504, Patras, Greece. Electronic address:

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 HO. 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.
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http://dx.doi.org/10.1016/j.jenvman.2021.113301DOI Listing
November 2021

Combined electrocoagulation and electrochemical oxidation treatment for groundwater denitrification.

J Environ Manage 2021 May 10;285:112068. Epub 2021 Feb 10.

Department of Chemical Engineering, University of Patras, Rio, GR-26504, Patras, Greece; Institute of Chemical Engineering Sciences (ICE-HT), Stadiou Str., Platani, GR-26504, Patras, Greece. Electronic address:

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-N concentration (25, 35, 45, 55 mg L) and applied current density (10, 20 mA cm) 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 NH-N L (for initial NO-N of 25 mg L). Therefore, EO was examined to oxidize the ammonium cations to nitrogen gas on iridium oxide coated titanium electrodes (IrO/Ti) anode surface. The effects of cathode material (aluminum, stainless steel), total current density and anode surface area (3.3-30 mA cm and 12-36 cm, respectively) were investigated, and lead to NH-N percentage removals of between 25% (10 mA cm, 12 cm) and 100% (30 mA cm, 24 cm) for an initial NH-N concentration of 10 mg L. The optimum EC (20 mA cm, natural initial pH 7.5-7.8) and EO parameters (30 mA cm, 24 cm surface area anode, Al cathode) were combined into a hybrid system to treat two real nitrate-polluted groundwaters with initial NO-N concentrations of 25 and 75 mg L. Results revealed that the proposed hybrid treatment system can be used to efficiently remove nitrate from groundwaters.
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http://dx.doi.org/10.1016/j.jenvman.2021.112068DOI Listing
May 2021

Collagen-Based Hydrogels Composites from Hide Waste to Produce Smart Fertilizers.

Materials (Basel) 2020 Oct 1;13(19). Epub 2020 Oct 1.

Research Center for Environmental Protection and Eco-friendly Technologies, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 1-7 Polizu str., RO-011061 Bucharest, Romania.

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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http://dx.doi.org/10.3390/ma13194396DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7579580PMC
October 2020

The Complex Interplay Between Extracellular Matrix and Cells in Tissues.

Methods Mol Biol 2019 ;1952:1-20

Department of Chemistry, University of Patras, Patras, Greece.

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.
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http://dx.doi.org/10.1007/978-1-4939-9133-4_1DOI Listing
July 2019

Newly isolated yeasts from Tunisian microhabitats: Lipid accumulation and fatty acid composition.

Eng Life Sci 2017 Mar 30;17(3):226-236. Epub 2016 Mar 30.

Laboratory of Enzyme Engineering and Microbiology National School of Engineers of Sfax University of Sfax Sfax Tunisia.

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 species; Group II ( and related); and Group III ( 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, BM1 was able to accumulate around 25% wt/wt lipid per dry cell mass and thus characterized as oleaginous. Some other strains, such as strain EL2, strain LV2, strain BM24, and 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.
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http://dx.doi.org/10.1002/elsc.201500156DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6999292PMC
March 2017

Microbial oils as food additives: recent approaches for improving microbial oil production and its polyunsaturated fatty acid content.

Curr Opin Biotechnol 2016 Feb 29;37:24-35. Epub 2015 Sep 29.

Division of Genetics, Cell & Development Biology, Department of Biology, University of Patras, Patras 26504, Greece; Department of Biology, King Abdulaziz University, Jeddah 21589, Saudi Arabia. Electronic address:

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.
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http://dx.doi.org/10.1016/j.copbio.2015.09.005DOI Listing
February 2016

Increased β-glucuronidase activity in bronchoalveolar lavage fluid of children with bacterial lung infection: A case-control study.

Respirology 2015 Nov 14;20(8):1248-54. Epub 2015 Jul 14.

Respiratory Unit, Department of Paediatrics, University General Hospital of Patras, Rion-Patras, Greece.

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.
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http://dx.doi.org/10.1111/resp.12596DOI Listing
November 2015

Feasibility of raw glycerol conversion into single cell oil by zygomycetes under non-aseptic conditions.

Biotechnol Bioeng 2015 Apr 23;112(4):827-31. Epub 2014 Dec 23.

Department of Biology, Unit of Microbiology, Division of Genetics, Cell and Development Biology, University of Patras, Patras, Greece.

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.
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http://dx.doi.org/10.1002/bit.25482DOI Listing
April 2015

Morphological and metabolic shifts of Yarrowia lipolytica induced by alteration of the dissolved oxygen concentration in the growth environment.

Microbiology (Reading) 2014 Apr 7;160(Pt 4):807-817. Epub 2014 Feb 7.

Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia.

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.
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http://dx.doi.org/10.1099/mic.0.074302-0DOI Listing
April 2014

Frontotemporal dementia, manifested as schizophrenia, with decreased heterochromatin on chromosome 1.

Case Rep Psychiatry 2012 2;2012:937518. Epub 2012 Oct 2.

Department of Psychiatry, School of Medicine and University Hospital of Patras, University of Patras, 26504 Rio, Patras, Greece.

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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http://dx.doi.org/10.1155/2012/937518DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3467798PMC
October 2012

Apolipoprotein A-I modulates processes associated with diet-induced nonalcoholic fatty liver disease in mice.

Mol Med 2012 Sep 7;18:901-12. Epub 2012 Sep 7.

Pharmacology Laboratory, Department of Medicine, University of Patras Medical School, Rio, Greece.

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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http://dx.doi.org/10.2119/molmed.2012.00113DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3459476PMC
September 2012

Biomechanical and structural changes following the decellularization of bovine pericardial tissues for use as a tissue engineering scaffold.

J Mater Sci Mater Med 2012 Jun 28;23(6):1387-96. Epub 2012 Mar 28.

Department of Mechanical Engineering & Aer/tics, University of Patras, Patras, Greece.

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.
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http://dx.doi.org/10.1007/s10856-012-4620-8DOI Listing
June 2012

The chondroitin/dermatan sulfate synthesizing and modifying enzymes in laryngeal cancer: expressional and epigenetic studies.

Head Neck Oncol 2010 Oct 7;2:27. Epub 2010 Oct 7.

1Department of Chemistry, Laboratory of Biochemistry, Section of Organic Chemistry and Natural Products, Karatheodori str, University of Patras, Patras, 26500, Greece.

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.
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http://dx.doi.org/10.1186/1758-3284-2-27DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2958872PMC
October 2010

A proposed mechanism for the inhibitory effect of the anticancer agent titanocene dichloride on tumour gelatinases and other proteolytic enzymes.

J Biol Inorg Chem 2009 Aug 24;14(6):947-57. Epub 2009 Apr 24.

Department of Chemistry, School of Natural Sciences, University of Patras, Patras, Greece.

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.
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http://dx.doi.org/10.1007/s00775-009-0507-7DOI Listing
August 2009
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