Konstantinos Anagnostopoulos

Democritus University of Thrace, Komotina, East Macedonia and Thrace, Greece

Are you Konstantinos Anagnostopoulos?

Claim your profile

Publications (7)13.52 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: In order to elucidate some basic principles for protein-ligand interactions, a subset of 87 structures of human proteins with their ligands was obtained from the PDB databank. After a short molecular dynamics simulation (to ensure structure stability), a variety of interaction energies and structural parameters were extracted. Linear regression was performed to determine which of these parameters have a potentially significant contribution to the protein-ligand interaction. The parameters exhibiting relatively high correlation coefficients were selected. Important factors seem to be the number of ligand atoms, the ratio of N, O and S atoms to total ligand atoms, the hydrophobic/polar aminoacid ratio and the ratio of cavity size to the sum of ligand plus water atoms in the cavity. An important factor also seems to be the immobile water molecules in the cavity. Nine of these parameters were used as known inputs to train a neural network in the prediction of seven other. Eight structures were left out of the training to test the quality of the predictions. After optimization of the neural network, the predictions were fairly accurate given the relatively small number of structures, especially in the prediction of the number of nitrogen and sulfur atoms of the ligand. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Computational Biology and Chemistry 02/2015; 56C. DOI:10.1016/j.compbiolchem.2015.02.016 · 1.60 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This study evaluated the effects of medications on IL-1 serum levels in treated patients with inflammatory bowel disease (IBD) during exacerbation and remission. Patients and methods: Sixty patients with established IBD, 34 with Crohn’s disease (CD) and 26 with ulcerative colitis (UC) were included. Disease activity was assessed during their regular visit at the outpatient clinic by using valid clinical indexes together with CRP and endoscopi/histological examination. Cytokine serum levels measured before the endoscopic procedure using the FIDIS human cytokine ELISA kit (BMD Biomedical diagnostics, Marne la Valle, France). Non-parametric tests were used for comparisons on cytokine levels in active and inactive disease, and in relation to treatment. Results: Active disease had 20/34 (58.8%) of CD, and 20/26 (76.9%) of UC patients. IL-1α levels were significantly higher as compared to inactive CD (11.2 vs 3.9 pg/ml; p=0.034). IL-1β and IL-1 receptor antagonist were significantly higher in active UC as compared to inactive disease (3.7 vs 2.3 pg/ml; p=0.054 and 15.9 vs 12.7 pg/ml; p=0.023, respectively). Aminosalycilate treatment significantly affected IL-1β (p=0.003) and marginally IL-1α (p=0.07) in patients with CD. Azathioprine affected significantly the levels of IL-1α (p=0.046), TNFα (p=0.015) and marginally IL-1β (p=0.07) in UC patients. No statistical difference was observed on IL-1 levels in CD patients treated with azathioprine or anti-TNFα. Conclusions: It seems that medications affect in various ways the levels of IL-1 which may in fact act as an escape phenomenon of the inflammation pathways, despite treatment, in patients with IBD.
    9th International Congress on Autoimmunity, Nice, France; 03/2014
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This study aims to investigate any associations of the proinflammatory cytokine IL-1 in treated patients with inflammatory bowel disease (IBD) and the enteropathic seronegative spondylarthritis (eSpA).Thirty-four patients with Crohn’s disease (CD), 26 with ulcerative colitis (UC) and 14 patients with SpA participated in the study. Valid clinical indexes, CRP values and the endoscopic and histologic examination were used for the determination of disease activity. IL-1α, IL-1β, IL-1 receptor antagonist (IL-1Ra) were measured by ELISA. Nonparametric tests were used for continuous and categorical data.Enteropathic SpA diagnosed in 29.4 % CD and 30.8 % UC patients. Active disease had 58.8 % CD (aCD), 76.9 % UC and 50 % SpA patients. Active and inactive CD (iCD) significantly differ on IL-1α levels (11.2 vs. 3.9 pg/ml; p = 0.034). Active and inactive UC significantly differ on IL-1β (3.7 vs. 2.3 pg/ml; p = 0.054) and IL-1Ra levels (15.9 vs. 12.7 pg/ml; p = 0.023). Active and inactive SpA (iSpA) significantly differ on IL-1Ra (16.9 vs. 14.8 pg/ml; p = 0.033) and marginally on IL-1α levels (20 vs. 3.9 pg/ml; p = 0.06). Patients with aCD/ieSpA exhibited significant differences on IL-1α (p = 0.022) compared to those with iCD/ieSpA.IL-1α is associated with CD activity, while IL-1β and IL-1Ra are associated with UC activity in treated patients with IBD. Prominent cytokine in SpAs seems to be IL-1α.
    12/2013; 4(3). DOI:10.1007/s13317-013-0049-4
  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigated the role of the prophylactic administration of the antioxidant 2-mercaptoethane sulfonate (mesna) on the hepatocyte-regenerating capacity following partial hepatectomy (PH) with concurrent Pringle maneuver. Wistar rats were subjected to PH (70% hepatectomy), 30 min Pringle maneuver, PH plus Pringle with or without mesna pretreatment (400 mg/kg, per os, 3 h before Pringle), or sham operation. At 24 h, 48 h, 72 h, and 1 week after operation, relative liver weight, hepatocyte mitotic activity (mitotic index), the histopathological score and serum aspartate aminotransferase, and alanine aminotransferase concentrations were assessed. At 1 h after operation, oxidative stress markers (glutathione to glutathione disulfide ratio, malondialdehyde concentration, and superoxide dismutase activity) and nuclear factor-kappaB (NF-kappaB) activity were assessed. Hepatectomy stimulated the regenerating process and induced mild oxidative stress and the activation of NF-kappaB in hepatocytes, while causing tissue injury in the remnant liver. When PH was performed under Pringle maneuver, hepatocyte mitotic activity was substantially suppressed, although Pringle alone initiated a delayed regenerating response. Furthermore, Pringle maneuver deteriorated oxidative stress markers, markedly increased NF-kappaB activity, and aggravated tissue injury, as compared to hepatectomy alone. Mesna pretreatment prevented the Pringle-induced antimitotic effect and the induction of oxidative stress, inhibited the activation of NF-kappaB, while attenuating liver injury after PH under Pringle. The excessive activation of NF-kappaB is related to the suppression of hepatocyte-regenerating activity following PH with concurrent liver ischemia. Mesna pretreatment protects the liver against the Pringle-induced antimitotic effect after PH via the prevention of oxidative stress and the inhibition of NF-kappaB activation.
    Journal of Gastroenterology and Hepatology 12/2008; 24(4):623-32. DOI:10.1111/j.1440-1746.2008.05641.x · 3.63 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigated the potential beneficial effect of the antioxidant 2-mercaptoethane-sulfonate (mesna) against oxidative stress induced by pneumoperitoneum in splanchnic organs. Wistar rats were subjected to either (a) CO(2) pneumoperitoneum (15 mmHg for 60 min) (group P), (b) pretreatment with mesna (400 mg/kg, p.o.) followed by pneumoperitoneum with a 180 min interval (group MP), (c) sham operation (group S), or (d) administration of mesna only (group M). Forty-five minutes after desufflation (groups P and MP), 60 + 45 min after the induction of anesthesia (group S), or 180 min after mesna administration (group M), tissue specimens were excised from liver, kidneys, jejunum and stomach. Tissue oxidative state was assessed on the basis of glutathione-to-glutathione disulfide ratio, malondialdehyde concentration , and superoxide dismutase activity. Pneumoperitoneum deteriorated all the oxidative stress markers in the organs studied. Mesna prevented the occurrence of oxidative stress following pneumoperitoneum in all the organs studied. In the absence of pneumoperitoneum, the administration of mesna caused mild enhancement of the oxidative state of liver, stomach, and kidneys compared to sham controls. Prophylaxis with mesna prevents oxidative stress induced by pneumoperitoneum in splanchnic organs.
    Surgical Endoscopy 04/2008; 23(3):583-9. DOI:10.1007/s00464-008-9887-y · 3.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Mesna (2-mercaptoethane-sulfonate) has been shown to attenuate oxidative injury induced by ischemia reperfusion (I/R) in the kidneys, the liver, and the intestine; however, its mechanism of action has not been fully elucidated. We sought to determine a prophylactic administration schedule of mesna that would confer optimal antioxidant protection on the intestinal mucosa following I/R and to investigate whether mesna's action is mediated via inhibition of nuclear factor-kappaB (NF-kappaB) activity. Wistar rats were subjected to one of the following: (a) induction of 30 min ischemia followed by 60 min reperfusion (I30/R60) of the intestine, (b) pretreatment with intraperitoneal or oral mesna at various time- and dose- administration schedules plus I30/R60, (c) sham operation, (d) no operation (controls), or (e) oral mesna alone. At the end of the reperfusion period or at various time points after mesna alone administration, the oxidative state of the intestinal mucosa was assessed in terms of glutathione to glutathione disulfide ratio, malondialdehyde concentration, and superoxide dismutase activity. In addition, NF-kappaB activity in the intestinal mucosa was assessed immunohistochemically in the oral mesna plus I/R and in the oral mesna alone groups. Sham operation caused mild stress, while I/R caused substantial oxidative stress in the intestinal mucosa. Mesna pretreatment had an antioxidant effect which varied from attenuation to prevention of oxidative stress. Over the two routes of administration, the oral proved to be more effective and had a time- and dose- dependent effect. The antioxidant action of mesna was not related to enhancement of the intestinal mucosa oxidative state. Furthermore, I/R induced NF-kappaB activation in the intestinal mucosa which was inhibited by mesna pretreatment. In the absence of oxidative damage, mesna led to downregulation of activated NF-kappaB. Prophylaxis with mesna prevents oxidative stress induced by I/R in the intestine via inhibition of NF-kappaB activation.
    Journal of Gastroenterology and Hepatology 03/2008; 23(2):328-35. DOI:10.1111/j.1440-1746.2007.05154.x · 3.63 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The present study was conducted to clarify the diagnostic and prognostic significance of TNF-alpha and its combination with HER-2 Ile655Val SNP in breast cancer. In this case-control study, 56 consecutive patients with primary breast cancer were prospectively evaluated. The control group consisted of 45 healthy women. Serum concentrations of TNF-alpha were measured by quantitative sandwich enzyme immunoassay (ELISA). HER-2 SNP was genotyped using the PCR-RFLP method. Serum TNF-alpha was significantly increased in patients compared to controls. ROC analysis indicated a cutoff point of 11.00 pg/mL to classify breast cancer patients (sensitivity, 86%; specificity, 71%). Elevated TNF-alpha levels were associated with larger, poorly differentiated, invasive and advanced-stage tumors, and >3 positive lymph nodes. Regarding HER-2 SNP, patients with Ile-Val and Val-Val genotypes had significant TNF-alpha elevation compared with homozygous Ile-Ile patients. In multivariate analysis, high serum TNF-alpha remained an independent prognostic factor of worse overall survival; its combination with Val-Val genotype predicted a worse prognosis than high TNF-alpha alone. Serum TNF-a could be used clinically as a useful tumor marker for diagnosis, disease extent and outcome of breast cancer. The negative impact on survival seems to be enhanced through the interaction with HER-2 Ile655Val SNP.
    The International journal of biological markers 25(3):126-35. · 1.36 Impact Factor