Andreas Papadopoulos - Academia.edu (original) (raw)

Papers by Andreas Papadopoulos

Eur Neuropsychopharmacol, 2008

European Neuropsychopharmacology the Journal of the European College of Neuropsychopharmacology, Apr 1, 2011

The activity of dentate gyrus granule neurons is under a strong GABAergic tonic inhibitory contro... more The activity of dentate gyrus granule neurons is under a strong GABAergic tonic inhibitory control which contributes to the sparse activation pattern of these neurons after environmental stimuli. Previously, we reported that in sparse dentate gyrus neurons such stimuli evoke Ser-10 (S10) phosphorylation and Lys-14 (K14) acetylation in the nucleosomal protein histone H3 (H3S10p-K14ac) resulting in the induction of c-Fos. We hypothesized that GABA is an important modulator of novelty stress-evoked epigenomic mechanisms in rat dentate neurons. As reported previously, exposure to novelty (30 min in new cage) evoked a significant increase in H3S10p-K14ac-and c-Fos-positive neuron numbers in the dentate gyrus. Pre-treatment of rats with the benzo Lorazepam, an indirect GABA-A receptor agonist, had no effects on baseline levels of H3S10p-K14ac and c-Fos but dosedependently inhibited the novelty-induced epigenomic effects. At the applied doses (0.1-0.3 mg/kg), Lorazepam's effects on behavior were mainly anxiolytic-like. To examine the effects of attenuated GABAergic inhibition on dentate granule neurons we applied the partial inverse GABA-A agonist FG-7142. This drug profoundly enhanced baseline levels as well as novelty-induced increases in the number of H3S10p-K14ac-and c-Fos-positive dentate neurons. Furthermore, FG-7142 evoked behavior in the novel cage congruous with increased anxiety and hyper-vigilance. Interestingly, the FG-7142-evoked enhancements in epigenomic changes were completely blocked by the NMDA receptor antagonist MK-801. We conclude that GABA tonically controls epigenomic responses to psychologically salient events in dentate gyrus granule neurons. Furthermore, GABA appears to exert its controller activity through modulation of NMDA receptor function. These findings may be of significance for the elucidation of anxiety disorders especially PTSD.

Acta Orthopaedica Belgica, May 1, 2004

The authors present the results achieved in 26 patients who presented with intra-articular fractu... more The authors present the results achieved in 26 patients who presented with intra-articular fractures of the distal humerus (8 AO type C1, 8 C2 and 10 C3) and who were operatively treated between 1999 and 2001 ; they were retrospectively evaluated after a mean follow-up period of 70.2 months. There were 12 males and 14 females with a mean age of 46.1 years. After a standard posterior approach with olecranon osteotomy, internal fixation was achieved with unilateral or bilateral plates and screws, or isolated screws and/or Kirschner wires. Anterior intramuscular transposition of the ulnar nerve was performed in 14 of the patients. The results were evaluated using the criteria of Morrey. The results were graded as excellent in 6 patients (23.1%), very good in 15 (57.6%) and fair in 5 (19.3%). Complications included postoperative ulnar nerve palsy (1), wire migration (4), heterotopic ossification (3), infection (2) and material failure (2). The overall re-operation rate was 38.4%.

The Journal of Knee Surgery, May 1, 2006

1. J Knee Surg. 2006 Apr;19(2):125-7. Delayed diagnosis of a popliteal artery rupture after a pos... more 1. J Knee Surg. 2006 Apr;19(2):125-7. Delayed diagnosis of a popliteal artery rupture after a posteromedial tibial plateau fracture-dislocation. Papadopoulos AX, Panagopoulos A, Kouzelis A, Gliatis I, Dimakopoulos P. Department ...

Frontiers in Plant Science, 2016

Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipi... more Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree growth and increased vulnerability to pests and diseases. The anatomy of tree rings responds to these environmental conditions. Quantitatively, the width of a tree ring is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may cease during relatively cool and dry winters, only to resume in the same calendar year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing ring (MR). A dendrochronological network of Pinus halepensis was used to determine the relationship of MR to ECE. The network consisted of 113 sites, 1,509 trees, 2,593 cores, and 225,428 tree rings throughout the distribution range of the species. A total of 4,150 MR were identified. Binomial logistic regression analysis determined that MR frequency increased with increased cambial age. Spatial analysis indicated that the geographic areas of south-eastern Spain and northern Algeria contained the greatest frequency of MR. Dendroclimatic regression analysis indicated a non-linear relationship of MR to total monthly precipitation and mean temperature. MR are strongly associated with the combination of monthly mean temperature from previous October till current February and total precipitation from previous September till current May. They are likely to occur with total precipitation lower than 50 mm and temperatures higher than 5°C. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a complication for dendrochronology, MR formation is a fundamental response of trees to adverse environmental conditions. The demonstrated relationship of MR formation to ECE across this dendrochronological network in the Mediterranean basin shows the potential of MR analysis to reconstruct the history of past climatic extremes and to predict future forest dynamics in a changing climate.

Acta orthopaedica Belgica

The authors have retrospectively studied the results achieved with the AO/ASIF PFN system in the ... more The authors have retrospectively studied the results achieved with the AO/ASIF PFN system in the treatment of unstable intertrochanteric fractures of the proximal femur. Between June 1999 and February 2003, 51 patients with unstable intertrochanteric fractures of the proximal femur underwent intramedullary nailing with the PFN system. A total of 45 patients (28 women, 17 men, average age 72 years) with 46 unstable pertrochanteric fractures (21 31-A2, 25 31-A3,) were available for outcome analysis. Mean follow-up period was 20 months (range, 12 to 30). The Salvati and Wilson scale of hip function was used at the last follow-up clinical assessment. Intraoperative difficulties in the insertion of the nail or screws, fracture consolidation, technical or mechanical complications and delayed union, nonunion and avascular necrosis were registered as well. Solid union of the fracture was achieved in all patients except one who was revised to total hip arthroplasty because of avascular necrosis of the femoral head. Technical and mechanical complications were noted in 41.3% of the patients during the operation and in 30.4% at the follow-up period (2 cut-outs of the neck screw, 5 "Z effects" of the antirotational hip pin leading to femoral head protrusion in four of these cases, 1 case with reverse "Zeffect" and 2 implant failures, both revised to a long PFN implant). The overall rate of re-operation was 28.8%. The Salvati and Wilson score was > 25 in 27 (60%) of the patients. The PFN modifications might be responsible for the positive results in this study. Technical or mechanical complications seem to be related with the type of fracture, the operative technique and the time of weight bearing rather than the PFN system itself.

Monthly Notices of the Royal Astronomical Society, 2015

Osteosynthesis and Trauma Care, 2002

2013 IEEE/WIC/ACM International Joint Conferences on Web Intelligence (WI) and Intelligent Agent Technologies (IAT), 2013

ABSTRACT With the rapid emergence of the internet world, a lot of information networks become ava... more ABSTRACT With the rapid emergence of the internet world, a lot of information networks become available every day. In many cases, these information networks contain objects connected by multiple links and described by different attributes. In this paper the problem of clustering homogeneous information networks in groups with similar attributes and connections is studied. Clustering such networks is a challenging task due to different importance of links and attributes. In addition, it is not straightforward how to balance the links and attributes information. In this article we describe these challenges and propose a fuzzy clustering model as well as a fuzzy clustering algorithm, HASCOP. Extensive experimentation on real world datasets has shown that HASCOP can be successfully applied in such networks, demonstrating its efficacy and superiority against the state-of-the-art attributed graph clustering methods.

Acta orthopaedica Belgica, 2004

The authors present the results achieved in 26 patients who presented with intra-articular fractu... more The authors present the results achieved in 26 patients who presented with intra-articular fractures of the distal humerus (8 AO type C1, 8 C2 and 10 C3) and who were operatively treated between 1999 and 2001; they were retrospectively evaluated after a mean follow-up period of 70.2 months. There were 12 males and 14 females with a mean age of 46.1 years. After a standard posterior approach with olecranon osteotomy, internal fixation was achieved with unilateral or bilateral plates and screws, or isolated screws and/or Kirschner wires. Anterior intramuscular transposition of the ulnar nerve was performed in 14 of the patients. The results were evaluated using the criteria of Morrey. The results were graded as excellent in 6 patients (23.1%), very good in 15 (57.6%) and fair in 5 (19.3%). Complications included postoperative ulnar nerve palsy (1), wire migration (4), heterotopic ossification (3), infection (2) and material failure (2). The overall re-operation rate was 38.4%. The aut...

The journal of knee surgery, 2006

1. J Knee Surg. 2006 Apr;19(2):125-7. Delayed diagnosis of a popliteal artery rupture after a pos... more 1. J Knee Surg. 2006 Apr;19(2):125-7. Delayed diagnosis of a popliteal artery rupture after a posteromedial tibial plateau fracture-dislocation. Papadopoulos AX, Panagopoulos A, Kouzelis A, Gliatis I, Dimakopoulos P. Department ...

Medical science monitor : international medical journal of experimental and clinical research, 2007

Little has been written about the size of a bone defect that can be restored with one-stage lengt... more Little has been written about the size of a bone defect that can be restored with one-stage lengthening over a reamed intramedullary nail. Sixteen adult female sheep were divided into four main groups: a simple osteotomy group (group I) and three segmental defect groups (1-, 2-, and 3-cm gaps, groups II-IV). One intact left tibia from each group was also used as the non-osteotomized intact control group (group V). In all cases, the osteotomy was fixed with an interlocked Universal Humeral Nail after reaming to 7 mm. Healing of the osteotomies was evaluated after 16 weeks by biomechanical testing. The examined parameters were torsional stiffness, shear stress, and angle of torsion at the time of fracture. The regenerate bone obvious in x-rays in the groups with 1- and 2-cm gaps had considerable mechanical properties. Torsional stiffness in these two groups was nearly equal and its value was about 60% of the stiffness of the simple osteotomy group. Gradually decreasing stiffness was o...

Osteosynthesis and Trauma Care, 2004

Neuropharmacology, 2015

A range of medications target different aspects of the GABA system; understanding their effects i... more A range of medications target different aspects of the GABA system; understanding their effects is important to inform further drug development. Effects on the waking EEG comparing these mechanisms have not been reported; in this study we compare the effects on resting MEG spectra of the benzodiazepine receptor agonist zolpidem, the delta sub-unit selective agonist gaboxadol (also known as THIP) and the GABA reuptake inhibitor tiagabine. These were two randomised, single-blind, placebocontrolled, crossover studies in healthy volunteers, one using zolpidem 10 mg, gaboxadol 15 mg and placebo, and the other tiagabine 16 mg and placebo. Whole head MEG recordings and individual MEG spectra were divided into frequency bands. Baseline spectra were subtracted from each post-intervention spectra and then differences between intervention and placebo compared. After zolpidem there were significant increases in beta frequencies and reduction in alpha frequency power; after gaboxadol and tiagabine there were significant increases in power at all frequencies up to beta. Enhancement of tonic inhibition via extrasynaptic receptors by gaboxadol gives rise to a very different MEG signature from the synaptic action of zolpidem. Tiagabine theoretically can affect both types of receptor; from these MEG results it is likely that the latter is the more prominent effect here.

13th IEEE International Conference on BioInformatics and BioEngineering, 2013

ABSTRACT This paper introduces a novel service oriented pilot platform developed to support Tele-... more ABSTRACT This paper introduces a novel service oriented pilot platform developed to support Tele-Supervised rehabilitation programs for patients after hospitalization in Intensive Care Units. The platform is developed under the framework of the TeleRehabilitation project funded by the Cross Border Cooperation Programme Greece Cyprus 2007–2013 in order to successfully meet the main technological and clinical objectives of the project. The design and development of the platform is based on composite service architecture (aggregates smaller and fine-grained services such as Web Based applications, Clinical Information Systems and Video Communication Systems). The platform delivers sustainable, maintainable and high quality services and enables multiparty, interregional bidirectional audio/visual communication between clinical practitioners and post-ICU patients, enables patient group-based vital sign real time monitoring, individualized and group-based patient online training and patients clinical record bookkeeping.

Journal of Neuroscience, 2013

Psychedelic drugs produce profound changes in consciousness, but the underlying neurobiological m... more Psychedelic drugs produce profound changes in consciousness, but the underlying neurobiological mechanisms for this remain unclear. Spontaneous and induced oscillatory activity was recorded in healthy human participants with magnetoencephalography after intravenous infusion of psilocybin-prodrug of the nonselective serotonin 2A receptor agonist and classic psychedelic psilocin. Psilocybin reduced spontaneous cortical oscillatory power from 1 to 50 Hz in posterior association cortices, and from 8 to 100 Hz in frontal association cortices. Large decreases in oscillatory power were seen in areas of the default-mode network. Independent component analysis was used to identify a number of resting-state networks, and activity in these was similarly decreased after psilocybin. Psilocybin had no effect on low-level visually induced and motor-induced gamma-band oscillations, suggesting that some basic elements of oscillatory brain activity are relatively preserved during the psychedelic experience. Dynamic causal modeling revealed that posterior cingulate cortex desynchronization can be explained by increased excitability of deep-layer pyramidal neurons, which are known to be rich in 5-HT 2A receptors. These findings suggest that the subjective effects of psychedelics result from a desynchronization of ongoing oscillatory rhythms in the cortex, likely triggered by 5-HT 2A receptor-mediated excitation of deep pyramidal cells.

PLoS ONE, 2013

We investigated the variability of the climate-growth relationship of Aleppo pine across its dist... more We investigated the variability of the climate-growth relationship of Aleppo pine across its distribution range in the Mediterranean Basin. We constructed a network of tree-ring index chronologies from 63 sites across the region. Correlation function analysis identified the relationships of tree-ring index to climate factors for each site. We also estimated the dominant climatic gradients of the region using principal component analysis of monthly, seasonal, and annual mean temperature and total precipitation from 1,068 climatic gridpoints. Variation in ring width index was primarily related to precipitation and secondarily to temperature. However, we found that the dendroclimatic relationship depended on the position of the site along the climatic gradient. In the southern part of the distribution range, where temperature was generally higher and precipitation lower than the regional average, reduced growth was also associated with warm and dry conditions. In the northern part, where the average temperature was lower and the precipitation more abundant than the regional average, reduced growth was associated with cool conditions. Thus, our study highlights the substantial plasticity of Aleppo pine in response to different climatic conditions. These results do not resolve the source of response variability as being due to either genetic variation in provenance, to phenotypic plasticity, or a combination of factors. However, as current growth responses to inter-annual climate variability vary spatially across existing climate gradients, future climategrowth relationships will also likely be determined by differential adaptation and/or acclimation responses to spatial climatic variation. The contribution of local adaptation and/or phenotypic plasticity across populations to the persistence of species under global warming could be decisive for prediction of climate change impacts across populations. In this sense, a more complex forest dynamics modeling approach that includes the contribution of genetic variation and phenotypic plasticity can improve the reliability of the ecological inferences derived from the climate-growth relationships. Citation: de Luis M, Č ufar K, Di Filippo A, Novak K, Papadopoulos A, et al. (2013) Plasticity in Dendroclimatic Response across the Distribution Range of Aleppo Pine (Pinus halepensis). PLoS ONE 8(12): e83550.

Photochemistry and Photobiology, 1997

A technique based on the degree that light is depolarized when propagating inside tissues is demo... more A technique based on the degree that light is depolarized when propagating inside tissues is demonstrated for optical imaging in biomedical systems. The difference in the degree of polarization of the emerging light allows for the discrimination of different types of tissues. The technique was investigated in the transillumination and backscattering geometry and in both cases the potential of this method to image and separate out different types of tissues is demonstrated.

Journal of Psychopharmacology, 2010

This was a double blind, placebo-controlled, 4-way cross-over study in 12 healthy volunteer subje... more This was a double blind, placebo-controlled, 4-way cross-over study in 12 healthy volunteer subjects of the acute effects of three drugs each of which are used in the clinic to treat some forms of anxiety: propranolol 40 mg, hydroxyzine 25 mg, flupentixol 0.5 mg and placebo. Each test session consisted of inhalation of air for 20 min, 10-min rest, inhalation of CO2 7.5% for 20 min, 10-min rest, followed by a single vital capacity inhalation of 35% CO2. The CO2 7.5% was administered at peak drug effect. Subjective effects were measured using Visual Analogue Scales (VAS), the Panic Symptom Inventory and the Generalised Anxiety Disorder Assessment inventory. Twelve subjects participated (eight men), with a mean age of 25.9 years. The expected subjective effects of CO2 were seen and these were significantly different from effects of peak air. However, there were no statistically significant differences between the drugs or between drugs and placebo, indeed there was a trend for some VAS anxiety scores to be higher than placebo in the drug groups. There were some significant differences in cardiovascular responses to CO2, with propranolol significantly decreasing heart rate and flupentixol increasing blood pressure when compared with placebo. The lack of subjective anxiolytic actions of the three drugs contrasts with our previous findings with acute benzodiazepines and chronic selective serotonin reuptake inhibitor administration. It may be that prolonged treatment with these agents would be required to show anxiolytic effects, although it may also be that their efficacy is insufficient to be demonstrated in this model. The lack of anxiolytic actions of propranolol, despite a significant reduction in heart rate, is a further support for a central action of CO2 to produce anxiety.

Journal of Orthopaedic Trauma, 2004

A rare case of unilateral bicondylar fractures of the femoral condyles is presented. Internal fix... more A rare case of unilateral bicondylar fractures of the femoral condyles is presented. Internal fixation of the fragments was achieved by three cancellous lag screws, followed by a short period of cast immobilization and intensive physiotherapy. Full weight bearing was allowed 3 months postoperatively. Full range of motion of the knee and no presence of articular defects on femoral condyles were observed 2 years after hardware and heterotopic ossification removal.

Eur Neuropsychopharmacol, 2008

European Neuropsychopharmacology the Journal of the European College of Neuropsychopharmacology, Apr 1, 2011

The activity of dentate gyrus granule neurons is under a strong GABAergic tonic inhibitory contro... more The activity of dentate gyrus granule neurons is under a strong GABAergic tonic inhibitory control which contributes to the sparse activation pattern of these neurons after environmental stimuli. Previously, we reported that in sparse dentate gyrus neurons such stimuli evoke Ser-10 (S10) phosphorylation and Lys-14 (K14) acetylation in the nucleosomal protein histone H3 (H3S10p-K14ac) resulting in the induction of c-Fos. We hypothesized that GABA is an important modulator of novelty stress-evoked epigenomic mechanisms in rat dentate neurons. As reported previously, exposure to novelty (30 min in new cage) evoked a significant increase in H3S10p-K14ac-and c-Fos-positive neuron numbers in the dentate gyrus. Pre-treatment of rats with the benzo Lorazepam, an indirect GABA-A receptor agonist, had no effects on baseline levels of H3S10p-K14ac and c-Fos but dosedependently inhibited the novelty-induced epigenomic effects. At the applied doses (0.1-0.3 mg/kg), Lorazepam's effects on behavior were mainly anxiolytic-like. To examine the effects of attenuated GABAergic inhibition on dentate granule neurons we applied the partial inverse GABA-A agonist FG-7142. This drug profoundly enhanced baseline levels as well as novelty-induced increases in the number of H3S10p-K14ac-and c-Fos-positive dentate neurons. Furthermore, FG-7142 evoked behavior in the novel cage congruous with increased anxiety and hyper-vigilance. Interestingly, the FG-7142-evoked enhancements in epigenomic changes were completely blocked by the NMDA receptor antagonist MK-801. We conclude that GABA tonically controls epigenomic responses to psychologically salient events in dentate gyrus granule neurons. Furthermore, GABA appears to exert its controller activity through modulation of NMDA receptor function. These findings may be of significance for the elucidation of anxiety disorders especially PTSD.

Acta Orthopaedica Belgica, May 1, 2004

The authors present the results achieved in 26 patients who presented with intra-articular fractu... more The authors present the results achieved in 26 patients who presented with intra-articular fractures of the distal humerus (8 AO type C1, 8 C2 and 10 C3) and who were operatively treated between 1999 and 2001 ; they were retrospectively evaluated after a mean follow-up period of 70.2 months. There were 12 males and 14 females with a mean age of 46.1 years. After a standard posterior approach with olecranon osteotomy, internal fixation was achieved with unilateral or bilateral plates and screws, or isolated screws and/or Kirschner wires. Anterior intramuscular transposition of the ulnar nerve was performed in 14 of the patients. The results were evaluated using the criteria of Morrey. The results were graded as excellent in 6 patients (23.1%), very good in 15 (57.6%) and fair in 5 (19.3%). Complications included postoperative ulnar nerve palsy (1), wire migration (4), heterotopic ossification (3), infection (2) and material failure (2). The overall re-operation rate was 38.4%.

The Journal of Knee Surgery, May 1, 2006

1. J Knee Surg. 2006 Apr;19(2):125-7. Delayed diagnosis of a popliteal artery rupture after a pos... more 1. J Knee Surg. 2006 Apr;19(2):125-7. Delayed diagnosis of a popliteal artery rupture after a posteromedial tibial plateau fracture-dislocation. Papadopoulos AX, Panagopoulos A, Kouzelis A, Gliatis I, Dimakopoulos P. Department ...

Frontiers in Plant Science, 2016

Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipi... more Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree growth and increased vulnerability to pests and diseases. The anatomy of tree rings responds to these environmental conditions. Quantitatively, the width of a tree ring is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may cease during relatively cool and dry winters, only to resume in the same calendar year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing ring (MR). A dendrochronological network of Pinus halepensis was used to determine the relationship of MR to ECE. The network consisted of 113 sites, 1,509 trees, 2,593 cores, and 225,428 tree rings throughout the distribution range of the species. A total of 4,150 MR were identified. Binomial logistic regression analysis determined that MR frequency increased with increased cambial age. Spatial analysis indicated that the geographic areas of south-eastern Spain and northern Algeria contained the greatest frequency of MR. Dendroclimatic regression analysis indicated a non-linear relationship of MR to total monthly precipitation and mean temperature. MR are strongly associated with the combination of monthly mean temperature from previous October till current February and total precipitation from previous September till current May. They are likely to occur with total precipitation lower than 50 mm and temperatures higher than 5°C. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a complication for dendrochronology, MR formation is a fundamental response of trees to adverse environmental conditions. The demonstrated relationship of MR formation to ECE across this dendrochronological network in the Mediterranean basin shows the potential of MR analysis to reconstruct the history of past climatic extremes and to predict future forest dynamics in a changing climate.

Acta orthopaedica Belgica

The authors have retrospectively studied the results achieved with the AO/ASIF PFN system in the ... more The authors have retrospectively studied the results achieved with the AO/ASIF PFN system in the treatment of unstable intertrochanteric fractures of the proximal femur. Between June 1999 and February 2003, 51 patients with unstable intertrochanteric fractures of the proximal femur underwent intramedullary nailing with the PFN system. A total of 45 patients (28 women, 17 men, average age 72 years) with 46 unstable pertrochanteric fractures (21 31-A2, 25 31-A3,) were available for outcome analysis. Mean follow-up period was 20 months (range, 12 to 30). The Salvati and Wilson scale of hip function was used at the last follow-up clinical assessment. Intraoperative difficulties in the insertion of the nail or screws, fracture consolidation, technical or mechanical complications and delayed union, nonunion and avascular necrosis were registered as well. Solid union of the fracture was achieved in all patients except one who was revised to total hip arthroplasty because of avascular necrosis of the femoral head. Technical and mechanical complications were noted in 41.3% of the patients during the operation and in 30.4% at the follow-up period (2 cut-outs of the neck screw, 5 "Z effects" of the antirotational hip pin leading to femoral head protrusion in four of these cases, 1 case with reverse "Zeffect" and 2 implant failures, both revised to a long PFN implant). The overall rate of re-operation was 28.8%. The Salvati and Wilson score was > 25 in 27 (60%) of the patients. The PFN modifications might be responsible for the positive results in this study. Technical or mechanical complications seem to be related with the type of fracture, the operative technique and the time of weight bearing rather than the PFN system itself.

Monthly Notices of the Royal Astronomical Society, 2015

Osteosynthesis and Trauma Care, 2002

2013 IEEE/WIC/ACM International Joint Conferences on Web Intelligence (WI) and Intelligent Agent Technologies (IAT), 2013

ABSTRACT With the rapid emergence of the internet world, a lot of information networks become ava... more ABSTRACT With the rapid emergence of the internet world, a lot of information networks become available every day. In many cases, these information networks contain objects connected by multiple links and described by different attributes. In this paper the problem of clustering homogeneous information networks in groups with similar attributes and connections is studied. Clustering such networks is a challenging task due to different importance of links and attributes. In addition, it is not straightforward how to balance the links and attributes information. In this article we describe these challenges and propose a fuzzy clustering model as well as a fuzzy clustering algorithm, HASCOP. Extensive experimentation on real world datasets has shown that HASCOP can be successfully applied in such networks, demonstrating its efficacy and superiority against the state-of-the-art attributed graph clustering methods.

Acta orthopaedica Belgica, 2004

The authors present the results achieved in 26 patients who presented with intra-articular fractu... more The authors present the results achieved in 26 patients who presented with intra-articular fractures of the distal humerus (8 AO type C1, 8 C2 and 10 C3) and who were operatively treated between 1999 and 2001; they were retrospectively evaluated after a mean follow-up period of 70.2 months. There were 12 males and 14 females with a mean age of 46.1 years. After a standard posterior approach with olecranon osteotomy, internal fixation was achieved with unilateral or bilateral plates and screws, or isolated screws and/or Kirschner wires. Anterior intramuscular transposition of the ulnar nerve was performed in 14 of the patients. The results were evaluated using the criteria of Morrey. The results were graded as excellent in 6 patients (23.1%), very good in 15 (57.6%) and fair in 5 (19.3%). Complications included postoperative ulnar nerve palsy (1), wire migration (4), heterotopic ossification (3), infection (2) and material failure (2). The overall re-operation rate was 38.4%. The aut...

The journal of knee surgery, 2006

1. J Knee Surg. 2006 Apr;19(2):125-7. Delayed diagnosis of a popliteal artery rupture after a pos... more 1. J Knee Surg. 2006 Apr;19(2):125-7. Delayed diagnosis of a popliteal artery rupture after a posteromedial tibial plateau fracture-dislocation. Papadopoulos AX, Panagopoulos A, Kouzelis A, Gliatis I, Dimakopoulos P. Department ...

Medical science monitor : international medical journal of experimental and clinical research, 2007

Little has been written about the size of a bone defect that can be restored with one-stage lengt... more Little has been written about the size of a bone defect that can be restored with one-stage lengthening over a reamed intramedullary nail. Sixteen adult female sheep were divided into four main groups: a simple osteotomy group (group I) and three segmental defect groups (1-, 2-, and 3-cm gaps, groups II-IV). One intact left tibia from each group was also used as the non-osteotomized intact control group (group V). In all cases, the osteotomy was fixed with an interlocked Universal Humeral Nail after reaming to 7 mm. Healing of the osteotomies was evaluated after 16 weeks by biomechanical testing. The examined parameters were torsional stiffness, shear stress, and angle of torsion at the time of fracture. The regenerate bone obvious in x-rays in the groups with 1- and 2-cm gaps had considerable mechanical properties. Torsional stiffness in these two groups was nearly equal and its value was about 60% of the stiffness of the simple osteotomy group. Gradually decreasing stiffness was o...

Osteosynthesis and Trauma Care, 2004

Neuropharmacology, 2015

A range of medications target different aspects of the GABA system; understanding their effects i... more A range of medications target different aspects of the GABA system; understanding their effects is important to inform further drug development. Effects on the waking EEG comparing these mechanisms have not been reported; in this study we compare the effects on resting MEG spectra of the benzodiazepine receptor agonist zolpidem, the delta sub-unit selective agonist gaboxadol (also known as THIP) and the GABA reuptake inhibitor tiagabine. These were two randomised, single-blind, placebocontrolled, crossover studies in healthy volunteers, one using zolpidem 10 mg, gaboxadol 15 mg and placebo, and the other tiagabine 16 mg and placebo. Whole head MEG recordings and individual MEG spectra were divided into frequency bands. Baseline spectra were subtracted from each post-intervention spectra and then differences between intervention and placebo compared. After zolpidem there were significant increases in beta frequencies and reduction in alpha frequency power; after gaboxadol and tiagabine there were significant increases in power at all frequencies up to beta. Enhancement of tonic inhibition via extrasynaptic receptors by gaboxadol gives rise to a very different MEG signature from the synaptic action of zolpidem. Tiagabine theoretically can affect both types of receptor; from these MEG results it is likely that the latter is the more prominent effect here.

13th IEEE International Conference on BioInformatics and BioEngineering, 2013

ABSTRACT This paper introduces a novel service oriented pilot platform developed to support Tele-... more ABSTRACT This paper introduces a novel service oriented pilot platform developed to support Tele-Supervised rehabilitation programs for patients after hospitalization in Intensive Care Units. The platform is developed under the framework of the TeleRehabilitation project funded by the Cross Border Cooperation Programme Greece Cyprus 2007–2013 in order to successfully meet the main technological and clinical objectives of the project. The design and development of the platform is based on composite service architecture (aggregates smaller and fine-grained services such as Web Based applications, Clinical Information Systems and Video Communication Systems). The platform delivers sustainable, maintainable and high quality services and enables multiparty, interregional bidirectional audio/visual communication between clinical practitioners and post-ICU patients, enables patient group-based vital sign real time monitoring, individualized and group-based patient online training and patients clinical record bookkeeping.

Journal of Neuroscience, 2013

Psychedelic drugs produce profound changes in consciousness, but the underlying neurobiological m... more Psychedelic drugs produce profound changes in consciousness, but the underlying neurobiological mechanisms for this remain unclear. Spontaneous and induced oscillatory activity was recorded in healthy human participants with magnetoencephalography after intravenous infusion of psilocybin-prodrug of the nonselective serotonin 2A receptor agonist and classic psychedelic psilocin. Psilocybin reduced spontaneous cortical oscillatory power from 1 to 50 Hz in posterior association cortices, and from 8 to 100 Hz in frontal association cortices. Large decreases in oscillatory power were seen in areas of the default-mode network. Independent component analysis was used to identify a number of resting-state networks, and activity in these was similarly decreased after psilocybin. Psilocybin had no effect on low-level visually induced and motor-induced gamma-band oscillations, suggesting that some basic elements of oscillatory brain activity are relatively preserved during the psychedelic experience. Dynamic causal modeling revealed that posterior cingulate cortex desynchronization can be explained by increased excitability of deep-layer pyramidal neurons, which are known to be rich in 5-HT 2A receptors. These findings suggest that the subjective effects of psychedelics result from a desynchronization of ongoing oscillatory rhythms in the cortex, likely triggered by 5-HT 2A receptor-mediated excitation of deep pyramidal cells.

PLoS ONE, 2013

We investigated the variability of the climate-growth relationship of Aleppo pine across its dist... more We investigated the variability of the climate-growth relationship of Aleppo pine across its distribution range in the Mediterranean Basin. We constructed a network of tree-ring index chronologies from 63 sites across the region. Correlation function analysis identified the relationships of tree-ring index to climate factors for each site. We also estimated the dominant climatic gradients of the region using principal component analysis of monthly, seasonal, and annual mean temperature and total precipitation from 1,068 climatic gridpoints. Variation in ring width index was primarily related to precipitation and secondarily to temperature. However, we found that the dendroclimatic relationship depended on the position of the site along the climatic gradient. In the southern part of the distribution range, where temperature was generally higher and precipitation lower than the regional average, reduced growth was also associated with warm and dry conditions. In the northern part, where the average temperature was lower and the precipitation more abundant than the regional average, reduced growth was associated with cool conditions. Thus, our study highlights the substantial plasticity of Aleppo pine in response to different climatic conditions. These results do not resolve the source of response variability as being due to either genetic variation in provenance, to phenotypic plasticity, or a combination of factors. However, as current growth responses to inter-annual climate variability vary spatially across existing climate gradients, future climategrowth relationships will also likely be determined by differential adaptation and/or acclimation responses to spatial climatic variation. The contribution of local adaptation and/or phenotypic plasticity across populations to the persistence of species under global warming could be decisive for prediction of climate change impacts across populations. In this sense, a more complex forest dynamics modeling approach that includes the contribution of genetic variation and phenotypic plasticity can improve the reliability of the ecological inferences derived from the climate-growth relationships. Citation: de Luis M, Č ufar K, Di Filippo A, Novak K, Papadopoulos A, et al. (2013) Plasticity in Dendroclimatic Response across the Distribution Range of Aleppo Pine (Pinus halepensis). PLoS ONE 8(12): e83550.

Photochemistry and Photobiology, 1997

A technique based on the degree that light is depolarized when propagating inside tissues is demo... more A technique based on the degree that light is depolarized when propagating inside tissues is demonstrated for optical imaging in biomedical systems. The difference in the degree of polarization of the emerging light allows for the discrimination of different types of tissues. The technique was investigated in the transillumination and backscattering geometry and in both cases the potential of this method to image and separate out different types of tissues is demonstrated.

Journal of Psychopharmacology, 2010

This was a double blind, placebo-controlled, 4-way cross-over study in 12 healthy volunteer subje... more This was a double blind, placebo-controlled, 4-way cross-over study in 12 healthy volunteer subjects of the acute effects of three drugs each of which are used in the clinic to treat some forms of anxiety: propranolol 40 mg, hydroxyzine 25 mg, flupentixol 0.5 mg and placebo. Each test session consisted of inhalation of air for 20 min, 10-min rest, inhalation of CO2 7.5% for 20 min, 10-min rest, followed by a single vital capacity inhalation of 35% CO2. The CO2 7.5% was administered at peak drug effect. Subjective effects were measured using Visual Analogue Scales (VAS), the Panic Symptom Inventory and the Generalised Anxiety Disorder Assessment inventory. Twelve subjects participated (eight men), with a mean age of 25.9 years. The expected subjective effects of CO2 were seen and these were significantly different from effects of peak air. However, there were no statistically significant differences between the drugs or between drugs and placebo, indeed there was a trend for some VAS anxiety scores to be higher than placebo in the drug groups. There were some significant differences in cardiovascular responses to CO2, with propranolol significantly decreasing heart rate and flupentixol increasing blood pressure when compared with placebo. The lack of subjective anxiolytic actions of the three drugs contrasts with our previous findings with acute benzodiazepines and chronic selective serotonin reuptake inhibitor administration. It may be that prolonged treatment with these agents would be required to show anxiolytic effects, although it may also be that their efficacy is insufficient to be demonstrated in this model. The lack of anxiolytic actions of propranolol, despite a significant reduction in heart rate, is a further support for a central action of CO2 to produce anxiety.

Journal of Orthopaedic Trauma, 2004

A rare case of unilateral bicondylar fractures of the femoral condyles is presented. Internal fix... more A rare case of unilateral bicondylar fractures of the femoral condyles is presented. Internal fixation of the fragments was achieved by three cancellous lag screws, followed by a short period of cast immobilization and intensive physiotherapy. Full weight bearing was allowed 3 months postoperatively. Full range of motion of the knee and no presence of articular defects on femoral condyles were observed 2 years after hardware and heterotopic ossification removal.