Alexandra Barbouti - Academia.edu (original) (raw)

Papers by Alexandra Barbouti

Research paper thumbnail of Expression patterns of the activator protein-1 (AP-1) family members in lymphoid neoplasms

Clinical and Experimental Medicine, 2016

Research paper thumbnail of Association between the capitate-triquetrum distance and carpal collapse in scaphoid nonunion

Acta orthopaedica Belgica

The effect of the lunate type on carpal collapse in cases of scaphoid nonunion has not been thoro... more The effect of the lunate type on carpal collapse in cases of scaphoid nonunion has not been thoroughly investigated. The purpose of the present study was to determine whether any association exists or not between the capitate-triquetrum distance and occurrence of carpal collapse in cases of scaphoid nonunion. In a retrospective study, 76 patients with scaphoid nonunion formed two groups based on the capitate-triquetrum distance: forty-three patients with distance of less than 5mm and 33 patients with distance of 5mm or more. The two groups were comparable with respect to sex distribution, age, dominant hand involvement, manual labor, nonunion location and time from injury to final x-rays. Six patients (13.9%) in the capitate-triquetrum < 5mm group and 13 patients (39.4%) in the capitate-triquetrum ≥ 5 mm group had no signs of collapse, with significant difference (p < 0.05). Capitate-triquetrum distance could contribute in the decision making process for cases of scaphoid nonu...

Research paper thumbnail of Correlation between Manchester Grading Scale and American Orthopedic Foot and Ankle Society Score in Patients with Hallux Valgus

Medical principles and practice : international journal of the Kuwait University, Health Science Centre, Jan 3, 2015

&amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt; To evaluate the correlation be... more &amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt; To evaluate the correlation between Manchester grading scale and the American Orthopedic Foot and Ankle Society [AOFAS] preoperative score in patients with hallux valgus deformity.&amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt; Materials (Subjects) and Methods&amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt;The study sample included 181 feet of 122 patients with hallux valgus and 424 feet of 212 individuals without hallux valgus deformity as a control group. The severity of hallux valgus using the Manchester grading scale and the AOFAS score was determined on all individuals in the hallux valgus and the control group. Pearson correlation and the non parametric test Kruskal Wallis and Mann-Whitney were used for data analysis. &amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt; Results: &amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt;The AOFAS total score in participants with no deformity was 99.14. In patients with mild or moderate deformity the total score was 86.20 and 68.19 respectively. In severe hallux valgus the total score has been found to be 44.69. Statistically significant differences between the four grades of Manchester grading scale were present for the AOFAS total score (p=0.000) . In Pearson correlation, strong negative correlations were found between the AOFAS score and hallux valgus angle ( r = -0.899, p=0.000). Strong negative correlations were demonstrated between the AOFAS score and the first intermetatatarsal angle as well (r = -0.748, p=0.000)&amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt; Conclusion:&amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt;High negative correlation between Manchester grading scale and AOFAS score was observed, as the severity of hallux valgus is increased, the AOFAS score seemed to decrease. &amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt;.

Research paper thumbnail of A brief exposure to low pH prior to refrigerated storage reduces the motility and viability of goldfish sperm ( Carassius auratus , Linnaeus, 1758)

Journal of Applied Ichthyology, Jan 2015

Optimal conditions of short-term storage of fish sperm are important for successful artificial re... more Optimal conditions of short-term storage of fish sperm are important for successful artificial reproduction protocols or incubation of sperm in a cryoprotecting medium for successful sperm cryopreservation. The influence of acid or alkaline incubating conditions on short term storage of goldfish sperm was investigated in a series of experiments. Goldfish sperm was diluted an immobilizing solution (1 : 3) and incubated for 1 h in acidic, pH 6.5 (AC group) or alkaline, pH 8.5 (AL group) conditions. Subsequently, the sperm of both groups was further diluted (1 : 3) in the immobilizing solution and the pH was adjusted to pH 7.51 (AE0.02) and 7.56 (AE0.07) in the AC and AL group respectively. The samples were kept in sealed bags and stored at 4°C. Viability (%) and motility (%) was estimated in samples obtained daily for the next 4 days. The results indicate that even a brief exposure of sperm to acid acidic conditions prior to storage accelerated the decline of sperm viability and motility during refrigeration.

Research paper thumbnail of Metal Ion in Stroke

Research paper thumbnail of Lipophilic caffeic acid derivatives protect cells against H2O2-induced DNA damage by chelating intracellular “labile iron”

Free Radical Biology and Medicine, 2013

Naturally occurring cinnamic acid derivatives are ubiquitously distributed in the plant kingdom, ... more Naturally occurring cinnamic acid derivatives are ubiquitously distributed in the plant kingdom, and it has been proposed that their consumption contributes to the maintenance of human health. However, the molecular mechanisms underlying their health keeping effects remain unknown. In the present investigation, we evaluated the capacity of several cinnamic acid derivatives (trans-cinnamic, p-coumaric, caffeic and ferulic acids, as well as caffeic acid-methyl and -propyl esters) to protect cells from oxidative stress-induced DNA damage. It was observed that effective protection was based on the ability of each compound to (i) reach the intracellular space and (ii) chelate intracellular "labile" iron. These results support the notion that numerous lipophilic iron chelating compounds, present abundantly in plant-derived diet components, may protect cells in conditions of oxidative stress and in this way be important contributors toward maintenance of human health.

Research paper thumbnail of DNA Fragmentation, Linear Velocity and Fertilising Ability of Reactivated Cryopreserved Goldfish Sperm using Different Cryoprotectants

Biotechnology(Faisalabad), 2011

Research paper thumbnail of Immunohistological Analysis of the Jun Family and the Signal Transducers and Activators of Transcription in Thymus

Anatomy Research International, 2015

Research paper thumbnail of Immunohistological characterization of thymic dendritic cells

In vivo (Athens, Greece)

Dendritic cells play key roles in thymic histophysiology and histopathology. Therefore, we analyz... more Dendritic cells play key roles in thymic histophysiology and histopathology. Therefore, we analyzed the immunotopographical distribution of cells expressing markers of dendritic cells and macrophages in postnatal human thymus. The streptavidin-biotin peroxidise-labeled (LSAB) and the double-LSAB/alkaline phosphatase/anti-alkaline phosphatase (APAAP) immunohistochemical procedures were used. S100 protein-, Cluster of designation 1a (CD1a)-, CD207-, CD11c- and CD123-positive cells, many of them exhibiting the morphology of dendritic cells, were detected in the cortex but mainly in the medulla. These markers, except CD123, were also detected in cells of juvenile and immature Hassall bodies. CD68- and CD163-positive cells were detected in the cortex and the medulla but not in Hassall bodies. The immunohistological detection of S100-, CD1a-, CD207- and CD11c-positive dendritic cells in juvenile and immature Hassall bodies may reflect an important role of these structures in the cooperati...

Research paper thumbnail of Immunohistological Analysis of the Jun Family and the Signal Transducers and Activators of Transcription in Thymus

Anatomy Research International, 2015

Research paper thumbnail of Expression of cell cycle and apoptosis regulators in thymus and thymic epithelial tumors

Clinical and experimental medicine, Jan 21, 2015

The human thymus supports the production of self-tolerant T cells with competent and regulatory f... more The human thymus supports the production of self-tolerant T cells with competent and regulatory functions. Various cellular components of the thymic microenvironment such as thymic epithelial cells (TEC) and dendritic cells play essential roles in thymic T cell differentiation. The multiple cellular events occurring during thymic T cell and TEC differentiation involve proteins regulating cell cycle and apoptosis. Dysregulation of the cell cycle and apoptosis networks is involved in the pathogenesis of thymic epithelial tumors (TET) which are divided into two broad categories, thymomas and thymic carcinomas. The present review focuses on the usefulness of the analysis of the expression patterns of major cell cycle and apoptosis regulators in order to gain insight in the histophysiology of thymus and the histopathology, the clinical behavior and the biology of TET.

Research paper thumbnail of Oxidative Modification of Albumin in Predialysis, Hemodialysis, and Peritoneal Dialysis Patients

Nephron Clinical Practice, 2009

Background/Aims: Oxidative damage has been reported to be involved in the pathophysiology of chro... more Background/Aims: Oxidative damage has been reported to be involved in the pathophysiology of chronic kidney disease (CKD) as well as in the pathogenesis of cardiovascular complications of CKD patients. The aim of the present investigation was to evaluate the levels of plasma carbonyl formation, a sensitive marker of enhanced oxidative stress in predialysis, hemodialysis (HD) and peritoneal dialysis (PD) patients.

Research paper thumbnail of Redox signaling and cancer: The role of “labile” iron

Cancer Letters, 2008

Reactive oxygen species (ROS) were viewed for a long time as unavoidable by-products of normal ce... more Reactive oxygen species (ROS) were viewed for a long time as unavoidable by-products of normal cell catabolism. This view has recently changed and it is now apparent that ROS generation is a tightly regulated process that plays a central role in cell signaling. Thus, it is known that regulated changes in intracellular ROS levels can induce biochemical signaling processes that

Research paper thumbnail of SIN1-induced DNA damage in isolated human peripheral blood lymphocytes as assessed by single cell gel electrophoresis (comet assay)

Free Radical Biology and Medicine, 2001

Human lymphocytes were exposed to increasing concentrations of SIN-1, which generates superoxide ... more Human lymphocytes were exposed to increasing concentrations of SIN-1, which generates superoxide and nitric oxide, and the formation of single-strand breaks (SSB) in individual cells was determined by the single-cell gel electrophoresis assay (comet assay). A dose- and time-dependent increase in SSB formation was observed rapidly after the addition of SIN-1 (0.1–15 mM). Exposure of the cells to SIN-1 (5

Research paper thumbnail of Role of compartmentalized redox-active iron in hydrogen peroxide-induced DNA damage and apoptosis

Biochemical Journal, 2005

Jurkat cells in culture were exposed to oxidative stress in the form of continuously generated hy... more Jurkat cells in culture were exposed to oxidative stress in the form of continuously generated hydrogen peroxide, obtained by the addition of glucose oxidase to the medium. This treatment induced a rapid, dose-dependent increase in the ICIP (intracellular calcein-chelatable iron pool). Early destabilization of lysosomal membranes and subsequent nuclear DNA strand breaks were also observed, as evaluated by the Acridine Orange relocation test and the comet assay respectively. Somewhat later, these effects were followed by a lowered mitochondrial membrane potential, with release of cytochrome c and apoptosis-inducing factor. These events were all prevented if cells were pretreated with the potent iron chelator DFO (desferrioxamine) for a period of time (2-3 h) long enough to allow the drug to reach the lysosomal compartment following fluid-phase endocytosis. The hydrophilic calcein, a cleavage product of calcein acetoxymethyl ester following the action of cytosolic esterases, obviously does not penetrate intact lysosomal membranes, thus explaining why ICIP increased dramatically following lysosomal rupture. The rapid decrease in ICIP after addition of DFO to the medium suggests draining of cytosolic iron to the medium, rather than penetration of DFO through the plasma membrane. Most importantly, these observations directly connect oxidative stress and resultant DNA damage with lysosomal rupture and the release of redox-active iron into the cytosol and, apparently, the nucleus.

Research paper thumbnail of DNA damage and apoptosis in hydrogen peroxide-exposed Jurkat cells: bolus addition versus continuous generation of H 2O 2

Free Radical Biology and Medicine, 2002

Aspects of the molecular mechanism(s) of hydrogen peroxide-induced DNA damage and cell death were... more Aspects of the molecular mechanism(s) of hydrogen peroxide-induced DNA damage and cell death were studied in the present investigation. Jurkat T-cells in culture were exposed either to low rates of continuously generated H2O2 by the action of glucose oxidase or to a bolus addition of the same agent. In the first case, steady state conditions were prevailing, while in the

Research paper thumbnail of Protective Effects of Olive Oil Components Against Hydrogen Peroxide-Induced DNA Damage

Olives and Olive Oil in Health and Disease Prevention, 2010

Research paper thumbnail of Hydrogen peroxide inhibits caspase-dependent apoptosis by inactivating procaspase-9 in an iron-dependent manner

Free radical biology & medicine, Jan 15, 2007

Apoptosis represents a physiological form of cell death, the perturbation of which may contribute... more Apoptosis represents a physiological form of cell death, the perturbation of which may contribute to the development of several diseases connected with accumulation of unwanted cells or excessive cell loss. We have previously shown that the continuous presence of low concentrations of H2O2 (generated by the action of glucose oxidase) was able to inhibit caspase-mediated apoptosis in Jurkat cells. The main purpose of the present study was to elucidate the exact molecular mechanism(s) underlying this inhibitory action of H2O2. The results presented show that events like outer mitochondrial membrane permeabilization, release of cytochrome c from mitochondria, oligomerization of Apaf-1, and recruitment of procaspase-9 to apoptosomes were taking place normally, but further advancement toward activation of the execution caspases was interrupted when H2O2 was present during the apoptotic process. From the results presented in this work, it emerges that the inhibition of procaspase-9 autoac...

Research paper thumbnail of Relationship between pedographic analysis and the Manchester scale in hallux valgus

Acta orthopaedica et traumatologica turcica, 2015

The aim of this study was to evaluate the correlation between the Manchester scale and foot press... more The aim of this study was to evaluate the correlation between the Manchester scale and foot pressure distribution in patients with hallux valgus deformity. The study included 152 feet of 87 patients with hallux valgus and a control group of 391 feet of 241 individuals without hallux valgus deformity. The severity of hallux valgus was determined using the Manchester scale grading system. Plantar loading patterns in 10 foot areas were determined for all participants. According to the Manchester scale, 72% of the participants had no, 12.9% mild, 10.7% moderate and 4.4% severe deformity. The Manchester scale grade was highly correlated with both hallux valgus angle and first intermetatarsal angle (p=0.00). Significant differences between the four grades were present for mean pressure under the hallux and the first and second metatarsal heads only (p=0.00). The load distribution under these areas was higher as the hallux valgus progressed from mild to more severe. In all groups, the high...

Research paper thumbnail of Immunohistological characterization of thymic dendritic cells

In vivo (Athens, Greece)

Dendritic cells play key roles in thymic histophysiology and histopathology. Therefore, we analyz... more Dendritic cells play key roles in thymic histophysiology and histopathology. Therefore, we analyzed the immunotopographical distribution of cells expressing markers of dendritic cells and macrophages in postnatal human thymus. The streptavidin-biotin peroxidise-labeled (LSAB) and the double-LSAB/alkaline phosphatase/anti-alkaline phosphatase (APAAP) immunohistochemical procedures were used. S100 protein-, Cluster of designation 1a (CD1a)-, CD207-, CD11c- and CD123-positive cells, many of them exhibiting the morphology of dendritic cells, were detected in the cortex but mainly in the medulla. These markers, except CD123, were also detected in cells of juvenile and immature Hassall bodies. CD68- and CD163-positive cells were detected in the cortex and the medulla but not in Hassall bodies. The immunohistological detection of S100-, CD1a-, CD207- and CD11c-positive dendritic cells in juvenile and immature Hassall bodies may reflect an important role of these structures in the cooperati...

Research paper thumbnail of Expression patterns of the activator protein-1 (AP-1) family members in lymphoid neoplasms

Clinical and Experimental Medicine, 2016

Research paper thumbnail of Association between the capitate-triquetrum distance and carpal collapse in scaphoid nonunion

Acta orthopaedica Belgica

The effect of the lunate type on carpal collapse in cases of scaphoid nonunion has not been thoro... more The effect of the lunate type on carpal collapse in cases of scaphoid nonunion has not been thoroughly investigated. The purpose of the present study was to determine whether any association exists or not between the capitate-triquetrum distance and occurrence of carpal collapse in cases of scaphoid nonunion. In a retrospective study, 76 patients with scaphoid nonunion formed two groups based on the capitate-triquetrum distance: forty-three patients with distance of less than 5mm and 33 patients with distance of 5mm or more. The two groups were comparable with respect to sex distribution, age, dominant hand involvement, manual labor, nonunion location and time from injury to final x-rays. Six patients (13.9%) in the capitate-triquetrum < 5mm group and 13 patients (39.4%) in the capitate-triquetrum ≥ 5 mm group had no signs of collapse, with significant difference (p < 0.05). Capitate-triquetrum distance could contribute in the decision making process for cases of scaphoid nonu...

Research paper thumbnail of Correlation between Manchester Grading Scale and American Orthopedic Foot and Ankle Society Score in Patients with Hallux Valgus

Medical principles and practice : international journal of the Kuwait University, Health Science Centre, Jan 3, 2015

&amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt; To evaluate the correlation be... more &amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt; To evaluate the correlation between Manchester grading scale and the American Orthopedic Foot and Ankle Society [AOFAS] preoperative score in patients with hallux valgus deformity.&amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt; Materials (Subjects) and Methods&amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt;The study sample included 181 feet of 122 patients with hallux valgus and 424 feet of 212 individuals without hallux valgus deformity as a control group. The severity of hallux valgus using the Manchester grading scale and the AOFAS score was determined on all individuals in the hallux valgus and the control group. Pearson correlation and the non parametric test Kruskal Wallis and Mann-Whitney were used for data analysis. &amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt; Results: &amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt;The AOFAS total score in participants with no deformity was 99.14. In patients with mild or moderate deformity the total score was 86.20 and 68.19 respectively. In severe hallux valgus the total score has been found to be 44.69. Statistically significant differences between the four grades of Manchester grading scale were present for the AOFAS total score (p=0.000) . In Pearson correlation, strong negative correlations were found between the AOFAS score and hallux valgus angle ( r = -0.899, p=0.000). Strong negative correlations were demonstrated between the AOFAS score and the first intermetatatarsal angle as well (r = -0.748, p=0.000)&amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt; Conclusion:&amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt;High negative correlation between Manchester grading scale and AOFAS score was observed, as the severity of hallux valgus is increased, the AOFAS score seemed to decrease. &amp;amp;amp;amp;amp;amp;lt;br&amp;amp;amp;amp;amp;amp;gt;.

Research paper thumbnail of A brief exposure to low pH prior to refrigerated storage reduces the motility and viability of goldfish sperm ( Carassius auratus , Linnaeus, 1758)

Journal of Applied Ichthyology, Jan 2015

Optimal conditions of short-term storage of fish sperm are important for successful artificial re... more Optimal conditions of short-term storage of fish sperm are important for successful artificial reproduction protocols or incubation of sperm in a cryoprotecting medium for successful sperm cryopreservation. The influence of acid or alkaline incubating conditions on short term storage of goldfish sperm was investigated in a series of experiments. Goldfish sperm was diluted an immobilizing solution (1 : 3) and incubated for 1 h in acidic, pH 6.5 (AC group) or alkaline, pH 8.5 (AL group) conditions. Subsequently, the sperm of both groups was further diluted (1 : 3) in the immobilizing solution and the pH was adjusted to pH 7.51 (AE0.02) and 7.56 (AE0.07) in the AC and AL group respectively. The samples were kept in sealed bags and stored at 4°C. Viability (%) and motility (%) was estimated in samples obtained daily for the next 4 days. The results indicate that even a brief exposure of sperm to acid acidic conditions prior to storage accelerated the decline of sperm viability and motility during refrigeration.

Research paper thumbnail of Metal Ion in Stroke

Research paper thumbnail of Lipophilic caffeic acid derivatives protect cells against H2O2-induced DNA damage by chelating intracellular “labile iron”

Free Radical Biology and Medicine, 2013

Naturally occurring cinnamic acid derivatives are ubiquitously distributed in the plant kingdom, ... more Naturally occurring cinnamic acid derivatives are ubiquitously distributed in the plant kingdom, and it has been proposed that their consumption contributes to the maintenance of human health. However, the molecular mechanisms underlying their health keeping effects remain unknown. In the present investigation, we evaluated the capacity of several cinnamic acid derivatives (trans-cinnamic, p-coumaric, caffeic and ferulic acids, as well as caffeic acid-methyl and -propyl esters) to protect cells from oxidative stress-induced DNA damage. It was observed that effective protection was based on the ability of each compound to (i) reach the intracellular space and (ii) chelate intracellular "labile" iron. These results support the notion that numerous lipophilic iron chelating compounds, present abundantly in plant-derived diet components, may protect cells in conditions of oxidative stress and in this way be important contributors toward maintenance of human health.

Research paper thumbnail of DNA Fragmentation, Linear Velocity and Fertilising Ability of Reactivated Cryopreserved Goldfish Sperm using Different Cryoprotectants

Biotechnology(Faisalabad), 2011

Research paper thumbnail of Immunohistological Analysis of the Jun Family and the Signal Transducers and Activators of Transcription in Thymus

Anatomy Research International, 2015

Research paper thumbnail of Immunohistological characterization of thymic dendritic cells

In vivo (Athens, Greece)

Dendritic cells play key roles in thymic histophysiology and histopathology. Therefore, we analyz... more Dendritic cells play key roles in thymic histophysiology and histopathology. Therefore, we analyzed the immunotopographical distribution of cells expressing markers of dendritic cells and macrophages in postnatal human thymus. The streptavidin-biotin peroxidise-labeled (LSAB) and the double-LSAB/alkaline phosphatase/anti-alkaline phosphatase (APAAP) immunohistochemical procedures were used. S100 protein-, Cluster of designation 1a (CD1a)-, CD207-, CD11c- and CD123-positive cells, many of them exhibiting the morphology of dendritic cells, were detected in the cortex but mainly in the medulla. These markers, except CD123, were also detected in cells of juvenile and immature Hassall bodies. CD68- and CD163-positive cells were detected in the cortex and the medulla but not in Hassall bodies. The immunohistological detection of S100-, CD1a-, CD207- and CD11c-positive dendritic cells in juvenile and immature Hassall bodies may reflect an important role of these structures in the cooperati...

Research paper thumbnail of Immunohistological Analysis of the Jun Family and the Signal Transducers and Activators of Transcription in Thymus

Anatomy Research International, 2015

Research paper thumbnail of Expression of cell cycle and apoptosis regulators in thymus and thymic epithelial tumors

Clinical and experimental medicine, Jan 21, 2015

The human thymus supports the production of self-tolerant T cells with competent and regulatory f... more The human thymus supports the production of self-tolerant T cells with competent and regulatory functions. Various cellular components of the thymic microenvironment such as thymic epithelial cells (TEC) and dendritic cells play essential roles in thymic T cell differentiation. The multiple cellular events occurring during thymic T cell and TEC differentiation involve proteins regulating cell cycle and apoptosis. Dysregulation of the cell cycle and apoptosis networks is involved in the pathogenesis of thymic epithelial tumors (TET) which are divided into two broad categories, thymomas and thymic carcinomas. The present review focuses on the usefulness of the analysis of the expression patterns of major cell cycle and apoptosis regulators in order to gain insight in the histophysiology of thymus and the histopathology, the clinical behavior and the biology of TET.

Research paper thumbnail of Oxidative Modification of Albumin in Predialysis, Hemodialysis, and Peritoneal Dialysis Patients

Nephron Clinical Practice, 2009

Background/Aims: Oxidative damage has been reported to be involved in the pathophysiology of chro... more Background/Aims: Oxidative damage has been reported to be involved in the pathophysiology of chronic kidney disease (CKD) as well as in the pathogenesis of cardiovascular complications of CKD patients. The aim of the present investigation was to evaluate the levels of plasma carbonyl formation, a sensitive marker of enhanced oxidative stress in predialysis, hemodialysis (HD) and peritoneal dialysis (PD) patients.

Research paper thumbnail of Redox signaling and cancer: The role of “labile” iron

Cancer Letters, 2008

Reactive oxygen species (ROS) were viewed for a long time as unavoidable by-products of normal ce... more Reactive oxygen species (ROS) were viewed for a long time as unavoidable by-products of normal cell catabolism. This view has recently changed and it is now apparent that ROS generation is a tightly regulated process that plays a central role in cell signaling. Thus, it is known that regulated changes in intracellular ROS levels can induce biochemical signaling processes that

Research paper thumbnail of SIN1-induced DNA damage in isolated human peripheral blood lymphocytes as assessed by single cell gel electrophoresis (comet assay)

Free Radical Biology and Medicine, 2001

Human lymphocytes were exposed to increasing concentrations of SIN-1, which generates superoxide ... more Human lymphocytes were exposed to increasing concentrations of SIN-1, which generates superoxide and nitric oxide, and the formation of single-strand breaks (SSB) in individual cells was determined by the single-cell gel electrophoresis assay (comet assay). A dose- and time-dependent increase in SSB formation was observed rapidly after the addition of SIN-1 (0.1–15 mM). Exposure of the cells to SIN-1 (5

Research paper thumbnail of Role of compartmentalized redox-active iron in hydrogen peroxide-induced DNA damage and apoptosis

Biochemical Journal, 2005

Jurkat cells in culture were exposed to oxidative stress in the form of continuously generated hy... more Jurkat cells in culture were exposed to oxidative stress in the form of continuously generated hydrogen peroxide, obtained by the addition of glucose oxidase to the medium. This treatment induced a rapid, dose-dependent increase in the ICIP (intracellular calcein-chelatable iron pool). Early destabilization of lysosomal membranes and subsequent nuclear DNA strand breaks were also observed, as evaluated by the Acridine Orange relocation test and the comet assay respectively. Somewhat later, these effects were followed by a lowered mitochondrial membrane potential, with release of cytochrome c and apoptosis-inducing factor. These events were all prevented if cells were pretreated with the potent iron chelator DFO (desferrioxamine) for a period of time (2-3 h) long enough to allow the drug to reach the lysosomal compartment following fluid-phase endocytosis. The hydrophilic calcein, a cleavage product of calcein acetoxymethyl ester following the action of cytosolic esterases, obviously does not penetrate intact lysosomal membranes, thus explaining why ICIP increased dramatically following lysosomal rupture. The rapid decrease in ICIP after addition of DFO to the medium suggests draining of cytosolic iron to the medium, rather than penetration of DFO through the plasma membrane. Most importantly, these observations directly connect oxidative stress and resultant DNA damage with lysosomal rupture and the release of redox-active iron into the cytosol and, apparently, the nucleus.

Research paper thumbnail of DNA damage and apoptosis in hydrogen peroxide-exposed Jurkat cells: bolus addition versus continuous generation of H 2O 2

Free Radical Biology and Medicine, 2002

Aspects of the molecular mechanism(s) of hydrogen peroxide-induced DNA damage and cell death were... more Aspects of the molecular mechanism(s) of hydrogen peroxide-induced DNA damage and cell death were studied in the present investigation. Jurkat T-cells in culture were exposed either to low rates of continuously generated H2O2 by the action of glucose oxidase or to a bolus addition of the same agent. In the first case, steady state conditions were prevailing, while in the

Research paper thumbnail of Protective Effects of Olive Oil Components Against Hydrogen Peroxide-Induced DNA Damage

Olives and Olive Oil in Health and Disease Prevention, 2010

Research paper thumbnail of Hydrogen peroxide inhibits caspase-dependent apoptosis by inactivating procaspase-9 in an iron-dependent manner

Free radical biology & medicine, Jan 15, 2007

Apoptosis represents a physiological form of cell death, the perturbation of which may contribute... more Apoptosis represents a physiological form of cell death, the perturbation of which may contribute to the development of several diseases connected with accumulation of unwanted cells or excessive cell loss. We have previously shown that the continuous presence of low concentrations of H2O2 (generated by the action of glucose oxidase) was able to inhibit caspase-mediated apoptosis in Jurkat cells. The main purpose of the present study was to elucidate the exact molecular mechanism(s) underlying this inhibitory action of H2O2. The results presented show that events like outer mitochondrial membrane permeabilization, release of cytochrome c from mitochondria, oligomerization of Apaf-1, and recruitment of procaspase-9 to apoptosomes were taking place normally, but further advancement toward activation of the execution caspases was interrupted when H2O2 was present during the apoptotic process. From the results presented in this work, it emerges that the inhibition of procaspase-9 autoac...

Research paper thumbnail of Relationship between pedographic analysis and the Manchester scale in hallux valgus

Acta orthopaedica et traumatologica turcica, 2015

The aim of this study was to evaluate the correlation between the Manchester scale and foot press... more The aim of this study was to evaluate the correlation between the Manchester scale and foot pressure distribution in patients with hallux valgus deformity. The study included 152 feet of 87 patients with hallux valgus and a control group of 391 feet of 241 individuals without hallux valgus deformity. The severity of hallux valgus was determined using the Manchester scale grading system. Plantar loading patterns in 10 foot areas were determined for all participants. According to the Manchester scale, 72% of the participants had no, 12.9% mild, 10.7% moderate and 4.4% severe deformity. The Manchester scale grade was highly correlated with both hallux valgus angle and first intermetatarsal angle (p=0.00). Significant differences between the four grades were present for mean pressure under the hallux and the first and second metatarsal heads only (p=0.00). The load distribution under these areas was higher as the hallux valgus progressed from mild to more severe. In all groups, the high...

Research paper thumbnail of Immunohistological characterization of thymic dendritic cells

In vivo (Athens, Greece)

Dendritic cells play key roles in thymic histophysiology and histopathology. Therefore, we analyz... more Dendritic cells play key roles in thymic histophysiology and histopathology. Therefore, we analyzed the immunotopographical distribution of cells expressing markers of dendritic cells and macrophages in postnatal human thymus. The streptavidin-biotin peroxidise-labeled (LSAB) and the double-LSAB/alkaline phosphatase/anti-alkaline phosphatase (APAAP) immunohistochemical procedures were used. S100 protein-, Cluster of designation 1a (CD1a)-, CD207-, CD11c- and CD123-positive cells, many of them exhibiting the morphology of dendritic cells, were detected in the cortex but mainly in the medulla. These markers, except CD123, were also detected in cells of juvenile and immature Hassall bodies. CD68- and CD163-positive cells were detected in the cortex and the medulla but not in Hassall bodies. The immunohistological detection of S100-, CD1a-, CD207- and CD11c-positive dendritic cells in juvenile and immature Hassall bodies may reflect an important role of these structures in the cooperati...