Apostolos Papalois

Γενικό Νοσοκομείο Σάμου Αγίου Παντελεήμονα, Vathy, North Aegean, Greece

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Publications (184)372.67 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Background Crohn's disease is still incurable. Compounds with anti-inflammatory and/or antioxidative effects are tested in various preclinical models of the disease. Our aim was to investigate the effects of sildenafil and lazaroid U74389G in an experimental rat model of trinitrobenzene sulfonic acid (TNBS)-induced colitis. Materials and Methods TNBS was instilled into the colon of male Wistar rats except for the first group. For 6 days the animals in group 3 were administered daily sildenafil per os, the rats in group 4 were administered daily U-74389G IV and the rats in group 5 were codministered daily sildenafil per os and IV U-74389G The rats in groups 1 and 2 were not administered any treatment. During the study the rat weights were recorded as a marker of clinical condition. The colon damage was evaluated using macroscopic (CMDI), microscopic (Geboes score) and biochemical analysis (tissue TNF-a and MDA). Results Sildenafil reduced TNF-a tissue levels and increased body weight. U-74389G reduced TNF-a, the macroscopic index of mucosal damage score (CMDI) and increased the weight. The combined treatment with sildenafil and U-74389G reduced tissue levels of TNF-a and MDA, lowered CMDI and microscopic Geboes score and increased the weight. Conclusions U-74389G demonstrated a significant anti-inflammatory activity related to its ability to reduce colonic TNF-a, CMDI score and improve weight change. We confirmed that sildenafil has anti-inflammatory capacity by reducing colonic TNF-a and by improving weight change. Finally, the combined treatment showed superior effects by reducing colonic TNF-a, colonic MDA, CMDI score, Geboes score, and by improving weight change.
    Journal of Surgical Research 09/2014; · 2.02 Impact Factor
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    ABSTRACT: The aim of this experiment was to study the effects of the antioxidant drug "U-74389G" on rat model, particularly in ischemia reperfusion protocol. The beneficial or other effects of that molecule were studied estimating the mean oophoritis (OI) lesions. Materials and methods: 40 rats were used of mean weight 231.875 g. OI was evaluated 60 min after reperfusion for groups A and C and 120 min after reperfusion for groups B and D. Groups A and B without the drug but C and D with U-74389G administration. Results were that U-74389G administration kept non-significantly increased the OI scores by 0.05+0.051 without lesions (p=0.3204). Reperfusion time kept non-significantly increased the OI scores by 0.05+0.051 also without lesions (p=0.3204). Nevertheless, U-74389G administration and reperfusion time together kept non-significantly increased the OI scores by 0.045+0.030 (p=0.1334). Conclusions: Results of this study indicate that U-74389G administration, reperfusion time and their interaction got on declining the increased OI scores from significant to non-significant level.
    Anti-inflammatory & anti-allergy agents in medicinal chemistry. 08/2014;
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    ABSTRACT: Βackground And Aim: Infliximab is effective in the induction and maintenance of remission in Crohn's disease. Whether, the perioperative administration of anti-TNF-a compromises intestinal healing leading to anastomotic failure and increased risk of postoperative complications, remains controversial. The aim of the study was to evaluate the effect of Infliximab on intestinal anastomosis healing. Methods: Fifty six wistar rats were divided into 4 groups: (a) 20 rats were subjected to excision of part of the terminal ileum followed by anastomosis which was evaluated on the 3rd or 7th postoperative day; (b) 20 rats received Infliximab and thereafter, the same surgical protocol as group (a) was followed; (c) 8 rats received Infliximab and served as relative control group; and (d) 8 served as absolute control group. Bursting pressure was used for testing intestinal healing. Additionally, the anastomoses were examined macroscopically, histologicaly and immunohistochemicaly for TGFb1, MMP1, MMP2 and Collagen V. The results were confirmed by Western blot analysis. Results: There were no significant differences in bursting pressures and septic intra-abdominal events among non-Infliximab (a) and Infliximab-treated (b) groups. Infliximab-treated (b) group showed mild to moderate inflammation, whereas the non-Infliximab (a) group exhibited severe inflammation. Expression of TGFb1, MMP2 and collagen V was significantly higher in the Infliximab-treated (b) group. Conclusion: Infliximab seems to influence intestinal healing in terms of less inflammatory activity and higher tissue remodeling activity.
    International Journal of Surgery (London, England) 08/2014; · 1.44 Impact Factor
  • Resuscitation 05/2014; 85:S4. · 4.10 Impact Factor
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    ABSTRACT: In addition to its role in the endogenous control of erythropoiesis, recombinant human erythropoietin (rh-EPO) has been shown to exert tissue protective properties in various experimental models. However, its role in the cardiac arrest (CA) setting has not yet been adequately investigated.
    The American journal of emergency medicine. 04/2014;
  • Neurological Sciences 04/2014; · 1.41 Impact Factor
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    ABSTRACT: Despite advances in surgical treatment options, large rotator cuff (r-c) tears still represent a challenge for orthopedic surgeons. The purpose of this study was to evaluate the temporary and spatial histological incorporation of fascia lata allografts, used for bridging artificially created defects of the r-c.
    International Journal of Shoulder Surgery 04/2014; 8(2):39-46.
  • BioMed Research International 03/2014; · 2.71 Impact Factor
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    ABSTRACT: Tumor necrosis factor (TNF)α is a cytokine exerting pleiotropic effects on critical cell functions and, most importantly, is the main regulator of pro-inflammatory cytokine production and a key player in the pathophysiology of numerous autoimmune diseases, including Crohn's disease. TNFα became a therapeutic target and TNFα blocking agents are currently used in the treatment of inflammatory diseases. Beyond the therapeutic benefits deriving from TNFα neutralization, amendments in the cellular functions of the immune system may as well induce potent immunosuppressive effects. An attenuated immune response may compromise the intestinal healing ability, thus leading to weaker anastomosis and increased risk of anastomotic leak and septic complications. This hypothesis raises great concerns about the safety of perioperative administration of anti-TNF and has been the endpoint of numerous studies. The aim of this review is to critically evaluate the evidence regarding the role of TNFα in anastomosis related complications after abdominal surgery in Crohn's disease patients.
    Journal of Gastrointestinal Surgery 03/2014; · 2.36 Impact Factor
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    ABSTRACT: The aim of this study was to demonstrate a percutaneous transauricular method of balloon angioplasty in high-cholesterol fed rabbits, as an innovative atherosclerosis model. Twenty male New Zealand rabbits were randomly divided into two groups of ten animals, as follows: atherogenic diet plus balloon angioplasty (group A) and atherogenic diet alone (group B). Betaalloon angioplasty was performed in the descending thoracic aorta through percutaneous catheterization of the auricular artery. Eight additional animals fed regular diet were served as long term control. At the end of 9 week period, rabbits were euthanized and thoracic aortas were isolated for histological, immunohistochemical and biochemical analysis. Atherogenic diet induced severe hypercholesterolemia in both group A and B (2802 +/- 188.59 and 4423 +/- 493.39 mg/dl respectively) compared to the control animals (55.5 +/- 11.82 mg/dl; P < 0.001). Group A atherosclerotic lesions appeared to be more advanced histologically (20% type IV and 80% type V) compared to group B lesions (50% type III and 50% type IV). Group A compared to group B atherosclerotic lesions demonstrated similar percentage of macrophages (79.5 +/- 9.56% versus 84 +/- 12.2%; P = 0.869), more smooth muscle cells (61 +/- 14.10% versus 40.5 +/- 17.07; P = 0.027), increased intima/media ratio (1.20 +/- 0.50 versus 0.62 +/- 0.13; P = 0.015) despite the similar degree of intimal hyperplasia (9768 +/- 1826.79 mum2 versus 12205 +/- 8789.23 mum2; P = 0.796), and further significant lumen deterioration (23722 +/- 4508.11 versus 41967 +/- 20344.61 mum2; P = 0.05) and total vessel area reduction (42350 +/- 5819.70 versus 73190 +/- 38902.79 mum2; P = 0.022). Group A and B animals revealed similar nitrated protein percentage (P = NS), but significantly higher protein nitration compared to control group (P < 0.01; P < 0.01, respectively). No deaths or systemic complications were reported. Transauricular balloon angioplasty constitutes a safe, minimally invasive and highly successful model of induced atherosclerosis in hyperlipidaemic rabbits.
    Lipids in Health and Disease 02/2014; 13(1):33. · 2.31 Impact Factor
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    ABSTRACT: ABSTRACT Introduction: The aim of this study was to develop a model of fibrous cholangitis in the offspring of gravid domestic pigs through the administration of 1,4-phenylene diisothiocyanate (DITC). Material and Methods: Six young domestic pigs and two gravid pigs with their offspring (21 pigs) were used as experimental models and six wild-type animals were used as controls. All pigs were divided into five main groups and five subgroups, according to their developmental stage and time of exposure to DITC. The following histopathological characteristics were quantitatively evaluated on a scale of 0-5: ductal proliferation, periportal fibrosis, inflammatory infiltration, periductal fibrosis and edema, intraluminal fibrosis, duct wall thickening, epithelial apoptosis, and arterial hyperplasia/hypertrophy. Results: Statistically significant differences were observed for most of the histopathological markers between the group of pigs' offspring that received DITC at early gestation and their control group. Moreover, the group of animals that were exposed to the agent at early gestation exhibited significant differences for all histopathological characteristics compared to the animals that were exposed at late gestation. On the other hand, no statistically significant differences were observed between the group of animals that received the agent at late gestation and their healthy controls. Conclusions: Administration of DITC to domestic pigs in early pregnancy may induce histopathological patterns of fibrous cholangitis to their offspring imitating biliary atresia. This model may provide insight to the pathogenesis of the obstructive cholangitis in pigs.
    Journal of Investigative Surgery 01/2014; · 1.32 Impact Factor
  • John K Triantafillidis, Apostolos E Papalois
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    ABSTRACT: Abstract Total parenteral nutrition (TPN) represents a therapeutic modality that could save the life of a patient with inflammatory bowel disease (IBD) facing severe nutritional problems, by restoring the patient's impaired nutritional status. TPN does not compete with enteral nutrition (EN), the latter being the first choice for all patients having anatomically intact and functionally normal digestive tract. TPN allows bowel rest while supplying adequate calorific intake and essential nutrients, and removes antigenic mucosal stimuli. The value of TPN in malnourished patients with intestinal failure due to CD is beyond doubt. However, it is difficult to suggest TPN as a sole treatment for active CD. An increased rate of remission could not be expected by applying TPN. The utility of TPN is restricted to certain cases involving efforts to close enterocutaneous or other complicated fistulas in patients with fistulizing CD, the treatment of short bowel syndrome following extensive resections for CD, or when EN is impractical for other reasons. There are no advantages of TPN therapy over EN therapy regarding fistula healing. TPN has no influence on the surgical intervention rate and little benefit by bypassing the intestinal passage could be expected. Also TPN shows no advantage if the disease is chronically active. However, an optimal supply of nutrients improves bowel motility, intestinal permeability and nutritional status, and reduces inflammatory reactions. TPN might be associated with an increased risk of adverse events, although TPN undertaken by experienced teams does not cause more complications than does EN.
    Scandinavian Journal of Gastroenterology 01/2014; 49(1):3-14. · 2.33 Impact Factor
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    ABSTRACT: Aims We investigated the role of endothelin-B receptors on sympathetic activation originating from the adrenal gland or from the myocardium and its impact on arrhythmogenesis during acute myocardial infarction. Main methods We studied two groups of rats (n = 120, 284 ± 2 g), namely wild-type and ETB-deficient. Myocardial infarction was induced by permanent ligation of the left coronary artery and ventricular tachyarrhythmias were evaluated from continuous electrocardiographic recordings. Sympathetic activation, measured by indices of heart rate variability, was evaluated after adrenalectomy or catecholamine depletion induced by reserpine. Acute left ventricular failure was assessed by total animal activity. Key findings Adrenalectomy decreased the total duration of tachyarrhythmias in ETB-deficient rats, but their incidence remained higher, compared to wild-type rats. After reserpine, heart rate variability indices and tachyarrhythmias were similar in the two groups during the initial, ischaemic phase. During evolving infarction, tachyarrhythmia duration was longer in ETB-deficient rats, despite lower sympathetic activation. Heart rate was lower in ETB-deficient rats throughout the 24-hour observation period, whereas activity was comparable in the two groups. Significance Endothelin-B receptors modulate sympathetic activation during acute myocardial infarction in the ventricular myocardium, but also in the adrenal gland. Sympathetic activation markedly increases early-phase ventricular tachyarrhythmias, but other mechanisms involving the endothelin system underlie delayed arrhythmogenesis.
    Life sciences 01/2014; · 2.56 Impact Factor
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    ABSTRACT: Introduction. An experimental epidural hematoma model was used to study the relation of ultrasound indices, namely, transcranial color-coded-Doppler (TCCD) derived pulsatility index (PI), optic nerve sheath diameter (ONSD), and pupil constriction velocity (V) which was derived from a consensual sonographic pupillary light reflex (PLR) test with invasive intracranial pressure (ICP) measurements. Material and Methods. Twenty rabbits participated in the study. An intraparenchymal ICP catheter and a 5F Swan-Ganz catheter (SG) for the hematoma reproduction were used. We successively introduced 0.1 mL increments of autologous blood into the SG until the Cushing reaction occurred. Synchronous ICP and ultrasound measurements were performed accordingly. Results. A constant increase of PI and ONSD and a decrease of V values were observed with increased ICP values. The relationship between the ultrasound variables and ICP was exponential; thus curved prediction equations of ICP were used. PI, ONSD, and V were significantly correlated with ICP (r (2) = 0.84 ± 0.076, r (2) = 0.62 ± 0.119, and r (2) = 0.78 ± 0.09, resp. (all P < 0.001)). Conclusion. Although statistically significant prediction models of ICP were derived from ultrasound indices, the exponential relationship between the parameters underpins that results should be interpreted with caution and in the current experimental context.
    The Scientific World Journal 01/2014; 2014:504248. · 1.73 Impact Factor
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    ABSTRACT: Objective. Evaluation of neuronal changes in an animal experimental model of normocapnic hypoxia- reoxygenation. Materials and Methods. Fifty male piglets were the study subjects; normocapnic hypoxia was induced in 40 piglets and ten were sham-operated (controls). When bradycardia and/or severe hypotension occurred, reoxygenation was initiated. Animals were allocated in 4 groups according to the oxygen concentration, they were resuscitated with 18%, 21%, 40%, and 100% O2. Persisting asystole despite 10 minutes of cardiopulmonary resuscitation and return of spontaneous circulation were the endpoints of the experiment. Surviving animals were euthanized and brain cortex samples were collected, hematoxylin and eosin-stained, and examined for apoptotic bodies observing 10 consecutive high power fields. Results. Histological examination of the control group did not show any pathological change. On the contrary, apoptosis of neurons was found in 87.5% of treated animals. When specimens were examined according to the oxygen concentration used for resuscitation, we found marked intergroup variability; a higher percentage of apoptotic neurons was observed in piglets of group 4 (100% oxygen) compared to the others (P = 0.001). Conclusions. This preliminary data shows that normocapnic hypoxia and reoxygenation in Landrace/Large White piglets resulted in significant histological changes in the brain cortex. The degree of pathological changes in cortical neurons was significantly associated with the oxygen concentration used for reoxygenation, with a higher percentage of apoptotic neurons being observed in piglets reoxygenated with 100% compared to 18% O2 and to 21% O2.
    BioMed research international. 01/2014; 2014:476349.
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    ABSTRACT: Export Date: 18 October 2014
    Turk Uroloji Dergisi 01/2014; 40(2):110-114.
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    TheScientificWorldJournal. 01/2014; 2014:737628.
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    ABSTRACT: Aim of this experimental study was to compare haemodynamic effects and outcome with early administration of amiodarone and adrenaline vs. adrenaline alone in pigs with prolonged ventricular fibrillation (VF). After 8 min of untreated VF arrest, bolus doses were administered of adrenaline (0.02 mg/kg) and either amiodarone (5 mg/kg) or saline (n = 8 per group) after randomisation. Cardiopulmonary resuscitation (CPR) was commenced immediately after drug administration, and defibrillation was attempted 2 min later. CPR was resumed for another 2 min after each defibrillation attempt, and the same dose of adrenaline was given every 4th minute during CPR. Haemodynamic monitoring and mechanical ventilation continued for 6 h after return of spontaneous circulation (ROSC), and the pigs were euthanised at 48 h. Researchers were blinded for drug groups throughout the study. There was no difference in rates of ROSC and 48-h survival with amiodarone vs. saline (5/8 vs. 7/8 and 0/8 vs. 3/8, respectively). Diastolic aortic pressure and coronary perfusion pressure were significantly lower with amiodarone during CPR and 1 min after ROSC (P < 0.05). The number of electric shocks required for terminating VF, time to ROSC and adrenaline dose were significantly higher with amiodarone (P < 0.01). The incidence of post-resuscitation tachyarrhythmias tended to be higher in the saline group (P = 0.081). Early administration of amiodarone did not improve ROSC or 48-h survival rates, and was associated with worse haemodynamics in this swine model of cardiac arrest.
    Acta Anaesthesiologica Scandinavica 01/2014; 58(1):114-22. · 2.36 Impact Factor
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    ABSTRACT: Perinatal asphyxia is attributed to hypoxia and/or ischemia around the time of birth and may lead to multiorgan dysfunction. Aim of this research article is to investigate whether different metabolomic profiles occurred according to oxygen concentration administered at resuscitation. In order to perform the experiment, forty newborn piglets were subjected to normocapnic hypoxia and reoxygenation and were randomly allocated in 4 groups resuscitated with different oxygen concentrations, 18%, 21%, 40%, and 100%, respectively. Urine metabolic profiles at baseline and at hypoxia were analysed by (1)H-NMR spectroscopy and metabolites were also identified by multivariate statistical analysis. Metabolic pathways associations were also built up by ingenuity pathway analysis (IPA). Bioinformatics analysis of metabolites characterized the effect of metabolism in the 4 groups; it showed that the 21% of oxygen is the most "physiological" and appropriate concentration to be used for resuscitation. Our data indicate that resuscitation with 21% of oxygen seems to be optimal in terms of survival, rapidity of resuscitation, and metabolic profile in the present animal model. These findings need to be confirmed with metabolomics in human and, if so, the knowledge of the perinatal asphyxia condition may significantly improve.
    BioMed research international. 01/2014; 2014:731620.
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    ABSTRACT: Background. Experimental data suggest that oral iron (I.) supplementation can worsen colitis in animals. Aim. To investigate the influence of various concentrations of orally administered I. in normal gut mucosa and mucosa of animals with TNBS colitis, as well as the influence of Mesalamine (M.) and Prednisolone (P.) on the severity of TNBS colitis following orally administered I. Methods and Materials. 156 Wistar rats were allocated into 10 groups. Colitis was induced by TNBS. On the 8th day, all animals were euthanatized. Activity of colitis and extent of tissue damage were assessed histologically. The levels of tissue tumor necrosis factor- α (t-TNF- α ) and tissue malondialdehyde (t-MDA) were estimated in all animal groups. Results. Moderate and high I. supplementation induced inflammation in the healthy colon and increased the activity of the experimentally induced TNBS colitis. Administration of M. on TNBS colitis following moderate iron supplementation (0.3 g/Kg diet) resulted in a significant improvement in the overall histological score as well as in two individual histological parameters. M. administration, however, did not significantly reduce the t-TNF- α levels (17.67 ± 4.92 versus 14.58 ± 5.71, P = 0.102), although it significantly reduced the t-MDA levels (5.79 ± 1.55 versus 3.67 ± 1.39, P = 0.000). Administration of M. on TNBS colitis following high iron supplementation (3.0 g/Kg diet) did not improve the overall histological score and the individual histological parameters, neither reduced the levels of t-TNF- α (16.57 ± 5.61 versus 14.65 ± 3.88, P = 0.296). However, M. significantly reduced the t-MDA levels (5.99 ± 1.37 versus 4.04 ± 1.41, P = 0.000). Administration of P. on TNBS colitis after moderate iron supplementation resulted in a significant improvement in the overall histological score as well as in three individual histological parameters. P. also resulted in a significant reduction in the t-TNF- α levels (17.67 ± 4.92 versus 12.64 ± 3.97, P = 0.003) and the t-MDA levels (5.79 ± 1.54 versus 3.47 ± 1.21, P = 0.001). Administration of P on TNBS colitis after high I. supplementation resulted in a significant improvement of the overall histological score and three individual histological parameters and significantly reduced the levels of t-TNF- α (16.6 ± 5.6 versus 11.85 ± 1.3, P = 0.001). Conclusion. I. can induce colonic inflammation and aggravate TNBS colitis. M. and P. can significantly improve the inflammatory process in the colonic mucosa in TNBS colitis aggravated by orally administered I. P. has a stable anti-TNF- α effect. These findings suggest that the harmful.
    BioMed Research International 01/2014; 2014:648535. · 2.71 Impact Factor

Publication Stats

814 Citations
372.67 Total Impact Points


  • 2013
    • Γενικό Νοσοκομείο Σάμου Αγίου Παντελεήμονα
      Vathy, North Aegean, Greece
  • 2011–2013
    • Università degli studi di Cagliari
      • Department of Environmental and Life Science
      Cagliari, Sardinia, Italy
    • General Hospital of Attica KAT
      Kēfissia, Attica, Greece
  • 2009–2013
    • University of Ioannina
      • • Καρδιολογική
      • • School of Medicine
      Yannina, Epirus, Greece
  • 1994–2013
    • Athens State University
      Athens, Alabama, United States
  • 2012
    • 401 GSNA
      Athínai, Attica, Greece
    • Università Telematica "E-Campus"
      Campobasso, Molise, Italy
  • 2011–2012
    • National and Kapodistrian University of Athens
      • • Department of Pharmaceutical Chemistry
      • • Faculty of Medicine
      Athens, Attiki, Greece
  • 2006–2012
    • Elpen Pharmaceuticals Co. Inc.
      Athínai, Attica, Greece
    • Forest Research Institute of Athens
      Athínai, Attica, Greece
  • 2007–2011
    • Red Cross Hospital, Athens
      Athínai, Attica, Greece
    • Democritus University of Thrace
      • Department of Internal Medicine I
      Komotiní, Anatoliki Makedonia kai Thraki, Greece
  • 2000–2010
      Athínai, Attica, Greece
  • 2008
    • Attikon University Hospital
      • Department of Cardiology
      Athens, Attiki, Greece
  • 2005
    • Laiko Hospital
      • First Department of Surgery
      Athínai, Attica, Greece
    • Onassis Cardiac Surgery Center
      • Department of Cardiology
      Kallithéa, Attiki, Greece
  • 1999–2001
    • Evangelismos Hospital
      Athínai, Attica, Greece