Nikolaos Antoniadis
Aristotle University of Thessaloniki
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Featured researches published by Nikolaos Antoniadis.
Journal of Surgical Research | 2010
Dimitrios Giakoustidis; Alexandros Giakoustidis; Stavros Iliadis; Kokona Koliakou; Nikolaos Antoniadis; Nikolaos Kontos; Georgios Papageorgiou; Eleni Kaldrimidou; Dimitrios Takoudas
INTRODUCTION Hepatic ischemia/reperfusion (I/R) activates Kupffer cells and initiates severe oxidative stress with enhanced production of reactive oxygen species (ROS) and tumor necrosis factor-alpha (TNF-alpha). ROS and TNF-alpha mediate the expression of nuclear factors and kinases, activating the signal transduction pathway, and triggering apoptosis. The aim of our study was to evaluate the potential protective effect of (-)-epigallocatechin-3-gallate (EGCG) administration in inhibition of apoptosis by attenuating the expression of NF-kappaB, c-Jun, and caspase-3 in a model of severe hepatic I/R. MATERIALS AND METHODS Thirty Wistar rats were allocated into three groups. Sham operation, I/R, and I/R-EGCG 50mg/kg. Hepatic ischemia was induced for 60min by Pringles maneuver. Malondialdehyde (MDA), myeloperoxidase (MPO), light histology, scanning electron microscopy, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and immunocytochemistry for NF-kappaB, c-Jun, caspase-3, analysis on liver specimens and aspartate (AST), and alanine (ALT) transferases analysis in serum, were performed 120min after reperfusion. RESULTS Apoptosis as indicated by TUNEL and caspase-3 was widely expressed in the I/R group but very limited in the EGCG treated group. Liver was stained positive for NF-kappaB and c-Jun in the I/R group but failed to be stained positive in the EGCG treated group. MDA, MPO, AST, and ALT showed marked increase in the I/R group and significant decrease in EGCG treated group. Significant alterations of liver specimens were observed by light histology and transmission electron microscopy whilst pretreatment with EGCG resulted in parenchymal preservation. CONCLUSIONS Administration of EGCG is likely to inhibit I/R-induced apoptosis and protect liver by down-regulating NF-kappaB and c-Jun signal transduction pathways.
Surgery | 2009
A. Papagiannis; D. Vrochides; G. Imvrios; Dimitrios Gakis; I. Fouzas; Nikolaos Antoniadis; Dimitrios Takoudas
BACKGROUND Our objective is to provide provision of primary and secondary patency rates data and incidence of complications. Despite the publication of some review articles and small prospective trials about vascular accesses, controversy still exists regarding the choice of the outflow conduit and especially the choice of the fistula to be formed in secondary and tertiary access procedures. METHODS This is a retrospective study of 2,422 consecutive patients who underwent 3,685 vascular access procedures in a tertiary care hospital, including radial-cephalic (RCAVF), brachial-cephalic (BCAVF), brachial-basilic (BBAVF), and prosthetic graft (PTFE) fistulas. Maximum follow-up period was 20 years. Actuarial patency rates were obtained by Kaplan-Meier analysis. RESULTS The median primary patency (days) of the most common 1st choices for vascular access were 712 (95% CI: 606, 818), 1,009 (95% CI: 823, 1,195), and 384 (95% CI: 273, 945) days for RCAVF, BCAVF, and PTFE, respectively. The median secondary patency was 1809 days (95% CI: 1,692, 1,926) for the RCAVF. The median primary patency of BBAVF (2nd or 3rd choice for vascular access) was 1,582 days (95% CI: 415, 2,749). The cumulative incidence of clinically important complications for the patients who received a RCAVF, BCAVF, BBAVF, and u-PTFE was 0.25, 0.57, 0.33, and 0.61 per patient-year, respectively. CONCLUSION We advocate maximal use of autogenous conduits, except probably the case of the older diabetic patient, in whom access at the antecubital fossa should be the first choice. BBAVF is an excellent fistula and should probably be constructed before prosthetic graft placement.
Journal of basic and clinical physiology and pharmacology | 2013
Theodoros Eleftheriadis; Georgios Pissas; Aggeliki Karioti; Georgia Antoniadi; Nikolaos Antoniadis; Vassilios Liakopoulos; Ioannis Stefanidis
Abstract Background: Most cancer cells rely on aerobic glycolysis. Dichloroacetate (DCA) inhibits aerobic glycolysis and is a promising relatively nontoxic anticancer compound. However, rapidly proliferating effector T-cells also rely on aerobic glycolysis, whereas regulatory T-cells (Treg) do not. The effect of DCA on glucose metabolism and Treg differentiation was evaluated in alloreactive lymphocytes. Methods: Peripheral blood mononuclear cells from healthy volunteers were used in a two-way mixed lymphocyte reaction. Lymphocyte proliferation was assessed by cell counting; DCA cytotoxicity, by lactate dehydrogenase release assay; and glucose uptake and aerobic glycolysis, by measuring in the supernatants the correspondent glucose and lactate concentrations. Interleukin-10 (IL-10) was measured in the supernatants, whereas the Treg signature transcription factor forkhead box P3 (FOXP3) was measured in cell lysates by means of enzyme-linked immunosorbent assay. Results: DCA had a minor effect on lymphocyte proliferation and cytotoxicity. However, DCA decreased glucose uptake and inhibited aerobic glycolysis. Finally, DCA markedly increased the production of IL-10 and the expression of FOXP3. Conclusions: DCA inhibits aerobic glycolysis and induces Treg differentiation in human alloreactive lymphocytes. This could result in decreased immunosurveillance in case of its use as an anticancer drug. However, DCA could play a role as an immunosuppressant in the fields of transplantation and autoimmunity.
Transplant International | 2014
Evangelos Cholongitas; Ioannis Goulis; Nikolaos Antoniadis; I. Fouzas; George Imvrios; Evangelos Akriviadis
New nucleos(t)ide agents (NAs) [entecavir (ETV) and tenofovir (TDF)] have made hepatitis B immunoglobulin (HBIG)‐sparing protocols an attractive approach against hepatitis B virus (HBV) recurrence after liver transplantation (LT). Twenty‐eight patients transplanted for HBV cirrhosis in our centre were prospectively evaluated. After LT, each patient received HBIG (1000 IU IM/day for 7 days and then monthly for 6 months) plus ETV or TDF and then continued with ETV or TDF monoprophylaxis. All patients had undetectable HBV DNA at the time of LT, and they were followed up with laboratory tests including glomerular filtration rate (GFR) after LT. All patients (11 under ETV and 17 under TDF) remained HBsAg/HBV DNA negative during the follow‐up period [median: 21 (range 9–43) months]. GFR was not different between TDF and ETV groups of patients at 6 and 12 months and last follow‐up (P value >0.05 for all comparisons). The two groups of patients were similar regarding their ratio of maximum rate of tubular phosphate reabsorption to the GFR (TmP/GFR). In conclusion, in this prospective study, we showed for the first time that maintenance therapy with ETV or TDF monoprophylaxis after 6 months of low‐dose HBIG plus ETV or TDF after LT is highly effective and safe.
Transplantation Proceedings | 2008
Dimitrios Giakoustidis; K. Diplaris; Nikolaos Antoniadis; A. Papagianis; N. Ouzounidis; I. Fouzas; D. Vrochides; D. Kardasis; Georgios Tsoulfas; Alexandros Giakoustidis; G. Miserlis; G. Imvrios; Dimitrios Takoudas
We retrospectively evaluated the use of double-j stent and the incidence of urological complications in 2 groups of patients who received a kidney transplant. From January 2005 to September 2007 we studied 172 patients receiving kidney transplants, 65 and 107 from living and cadaver donors, respectively. From the 172 patients, a total of 34 were excluded due to ureterostomy or Politano-Leadbetter ureterovesical anastomosis. Another 21 patients were excluded from the study due to graft loss due to acute or hyperacute rejection, cytomegalovirus (CMV) infection, or vascular complication. The remaining patients were divided into 2 groups: group A (44 patients) and B (73 patients) with versus without the use of a double-j-stent, respectively. The 2 groups were comparable in terms of donor and recipient gender, ischemia time, and delayed graft function. We failed to observes significant differences between the 2 groups in mean hospital stay (23 +/- 9 and 19 +/- 9), urinary leak (2.3% and 4.1%), and urinary tract infection (20.4% and 19.2%), among groups A and B, respectively. The only difference observed concerned the gravity of the urinary leak; no surgical intervention was needed among the double-j stent group versus 2 patients demanding ureterovesical reconstruction in the nonstent group. In conclusion, our data suggested that the routine use of a double-j stent for ureterovesical anastomosis neither significantly increased urinary tract infection rates, nor decreased the incidence of urinary leaks, but may decrease the gravity of the latter as evidenced by the need for surgical intervention.
Journal of Viral Hepatitis | 2015
Evangelos Cholongitas; Themistoklis Vasiliadis; Ioannis Goulis; I. Fouzas; Nikolaos Antoniadis; Evangelos Akriviadis
Recent studies showed that telbivudine in patients with hepatitis B virus (HBV) infection improved their glomerular filtration rate (GFR), but data regarding its impact on renal function in liver transplant (LT) recipients are very limited. We evaluated 17 consecutive recipients who received at baseline nucleos(t)ide analogue(s) (NAs) other than telbivudine for 12 months, and then they were switched to telbivudine prophylaxis for another 12 months. In each patient, laboratory data including evaluation of GFR (using MDRD and CKD‐EPI) were prospectively recorded. The changes in GFR (ΔGFR) between baseline and after 12 months (1st period) and between telbivudine initiation and 24 months (2nd period) were evaluated. All patients remained serum HBsAg and HBV‐DNA negative. GFR‐MDRD at baseline, 12 months and 24 months were 72 ± 18, 67.8 ± 16 and 70.3 ± 12mL/min, respectively, (P = 0.025 for comparison between 12 months and 24 months). ΔGFR at the 1st period was significantly lower, compared with ΔGFR at the 2nd period [mean ΔGFR‐MDRD: −4.2 (range: −24–9) vs 2.5 (range: −7–22) mL/min, P = 0.013; mean ΔGFR‐CKD‐EPI: −4.2 (range: −19–10) vs 4.0 (range: −7–23) mL/min, P = 0.004], although the serum levels of calcineurin inhibitors were similar between the two periods. A second group of recipients (n = 17) who remained under the same nontelbivudine NA(s) for 24 months had a decline in the mean eGFR during the total follow‐up period. In conclusion, we showed that telbivudine administration in LT recipients for HBV cirrhosis was effective and it was associated with significant improvement in renal function, but this remains to be confirmed in larger well‐designed studies.
Liver Transplantation | 2016
Evangelos Cholongitas; Nikolaos Antoniadis; Ioannis Goulis; I. Fouzas; Themistoklis Vasiliadis; Evangelos Akriviadis
A national, multicenter, retrospective study was conducted to assess the results obtained for liver transplant recipients with conversion to everolimus in daily practice. The study included 477 recipients (481 transplantations). Indications for conversion to everolimus were renal dysfunction (32.6% of cases), hepatocellular carcinoma (HCC; 30.2%; prophylactic treatment for 68.9%), and de novo malignancy (29.7%). The median time from transplantation to conversion to everolimus was 68.7 months for de novo malignancy, 23.8 months for renal dysfunction, and 7.1 months for HCC and other indications. During the first year of treatment, mean everolimus trough levels were 5.4 (standard deviation [SD], 2.7) ng/mL and doses remained stable (1.5 mg/day) from the first month after conversion. An everolimus monotherapy regimen was followed by 28.5% of patients at 12 months. Patients with renal dysfunction showed a glomerular filtration rate (4-variable Modification of Diet in Renal Disease) increase of 10.9 mL (baseline mean, 45.8 [SD, 25.3] versus 57.6 [SD, 27.6] mL/minute/1.73 m2) at 3 months after everolimus initiation (P < 0.001), and 6.8 mL at 12 months. Improvement in renal function was higher in patients with early conversion (<1 year). Adverse events were the primary reason for discontinuation in 11.2% of cases. The probability of survival at 3 years after conversion to everolimus was 83.0%, 71.1%, and 59.5% for the renal dysfunction, de novo malignancy, and HCC groups, respectively. Everolimus is a viable option for the treatment of renal dysfunction, and earlier conversion is associated with better recovery of renal function. Prospective studies are needed to confirm advantages in patients with malignancy. Liver Transpl 21:1056-1065, 2015.
Journal of Hepatology | 2012
Evangelos Cholongitas; Banwari Agarwal; Nikolaos Antoniadis; Andrew K. Burroughs
To the Editor, We read with great interest the study by Levesque et al. [1], recently published in the Journal of Hepatology, regarding the prognostic ability of ICU-specific scores, such as SOFA score, and liver-specific scores [Child-Pugh (CTP), standard MELD, and MELD-serum sodium scores] in 377 patients with cirrhosis admitted to their intensive care unit (ICU). As the authors mentioned, their study are in accordance with our systematic review [2] that general ICU prognostic models are superior to the CTP score in cirrhotics with acute deterioration of chronic liver disease, and they confirmed our previous study [3], which showed that the SOFA score had better discriminative accuracy for mortality, compared to the MELD score. To add to their evaluation, we report our experience in 412 patients with cirrhosis who were consecutively admitted to ICU. At admission, several variables, including demographic and clinical data, as well as laboratory parameters had been prospectively collected for each patient. During the ICU stay, gastrointestinal bleeding episodes, development of aspiration pneumonia and additional use of inotropes, mechanical ventilation or haemofiltration were also recorded. Univariate comparisons and then multivariate analysis of variables at baseline were performed to identify independent factors associated with mortality. Liver-specific prognostic models [CTP, standard MELD, MELD-sodium (MELD-Na, iMELD, and MESO) scores], as well as general ICU models (APACHE II and SOFA scores) were evaluated on ICU admission. In addition, we evaluated for the first time the performance of the re-weighted MELD. The discriminative ability of the prognostic models to predict the outcome of patients was evaluated by using AUC, while sensitivity, specificity, positive (PPV), and negative (NPV) predictive values were calculated. The overall mortality in ICU or in hospital was 61.2% and 187 (45.4%) patients died due to multiple organ failure. Arterial lactate was independently associated with mortality (OR: 1.23, p = 0.001). The cirrhotics who died, compared to those who survived, had significantly higher median values of CTP (12 vs. 10), APACHE II (21 vs. 16), MELD (28 vs. 18) MELD-sodium (MELD-Na: 32 vs. 23, iMELD: 47 vs. 37, and MESO: 2.1 vs. 1.4) scores, re-weighted MELD (5.4 vs. 4.1), and SOFA (12 vs. 9) scores (p <0.001) at admission. Table 1 shows the discriminative
Transplantation Proceedings | 2008
D. Vrochides; G. Imvrios; A. Papagiannis; Dimitrios Gakis; N. Ouzounidis; Dimitrios Giakoustidis; I. Fouzas; Nikolaos Antoniadis; A. Ntinas; Georgios Arsos; D. Kardasis; Dimitrios Takoudas
PURPOSE Technetium(99m) sestamibi (MIBI) has poor sensitivity and specificity when applied to patients with secondary hyperparathyroidism. We investigated whether the combination of MIBI with preoperative parameters increased its accuracy. PATIENTS AND METHODS This prospective study of 453 consecutive patients with secondary hyperparathyroidism who underwent parathyroidectomy (bilateral neck exploration) included preoperative MIBI scintigraphy compared with intraoperative and histopathology findings. Four patient groups were comprised according to the results: true positivity (TP), true negativity (TN), false positivity (FP), and false negativity (FN). RESULTS MIBI scintigraphy sensitivity, specificity, positive predictive value, and negative predictive value were 66.4%, 50%, 76.3%, and 37.9%, respectively. For the TP group, mean age and mean parathormone (PTH) value were 56 years and 754, respectively. The binary logistic regression for the prediction (1) or not (2) of TP was as follows: 0.138 + (-.011) * age + 0.001 * PTH (P = .012). For the TN group, the mean age and mean phosphate value were 49 years and 5.24, respectively. The binary logistic regression for the prediction (1) versus not (2) of the TN was as follows: -1.463 + age * (-.029) + phosphate * 0.233 (P = .012). CONCLUSION MIBI accuracy in patients with secondary hyperparathyroidism was increased when combined with other preoperative parameters. The sensitivity was increased as patients were older and the PTH levels were lower. The specificity was increased as patients were younger and the phosphate levels were lower.
Case Reports in Gastroenterology | 2008
Vassilios Papanikolaou; Dimitrios Giakoustidis; Paraskevi Margari; N. Ouzounidis; Nikolaos Antoniadis; Alexander Giakoustidis; Dimitrios Kardasis; Dimitrios Takoudas
We present a case of bilateral Morgagni hernia in a 68-year-old male with an intermittent history of progressive onset of breath shortness and occasional cardiac arrhythmias. Diagnosis was made by clinical examination and the findings in a plain chest radiograph and was confirmed by computed tomography scan. The patient was operated electively and subjected to a transabdominal approach. A bilateral subcostal incision revealed a large right side anterior diaphragmatic defect with a hernia containing the ascending colon, the majority of the transverse colon and a huge amount of omentum. Also a second smaller defect was found on the left side with no hernia inside. After large bowel and omentum had been taken down to the peritoneal cavity, both defects were primarily closed using interrupted nylon sutures without the use of a mesh. The patient recovered very well, had an uneventful postoperative course and was released on the 5th postoperative day. 15-month follow-up failed to reveal any signs of recurrence.