APOSTOLOS PAPALOIS

Dr. APOSTOLOS PAPALOIS

Medical Schools, Athens and Thessaloniki Universities, Athens, Greece

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 February 2024 in World Journal of Gastroenterology
Verified
Journal Article
Open access
JTJohn K Triantafillidis
John K Triantafillidis
MKManousos M Konstadoulakis
Manousos M Konstadoulakis
APAPOSTOLOS PAPALOIS
APOSTOLOS PAPALOIS
In this editorial, we comment on the article entitled “Advances and key focus areas in gastric cancer immunotherapy: A comprehensive scientometric and clinical trial review (1999-2023),” which was published in the recent issue of the World Journal of Gastroenterology . We focused on the results of the authors’ bibliometric analysis concerning gastric cancer immunotherapy, which they analyzed in depth by compiling the relevant publications of the last 20 years. Before that, we briefly describe the most recent data concerning the epidemiological parameters of gastric cancer (GC) in different countries, attempting to give an interpretation based on the etiological factors involved in the etiopathogenesis of the neoplasm. We then briefly discuss the conservative treatment (chemotherapy) of the various forms of this malignant neoplasm. We describe the treatment of resectable tumors, locally advanced neoplasms, and unresectable (advanced) cases. Special attention is given to modern therapeutic approaches with emphasis on immunotherapy, which seems to be the future of GC treatment, especially in combination with chemotherapy. There is also a thorough analysis of the results of the study under review in terms of the number of scientific publications, the countries in which the studies were conducted, the authors, and the scientific centers of origin, as well as the clinical studies in progress. Finally, an attempt is made to draw some con-clusions and to point out possible future directions.

10 September 2020 in Cureus
Verified
Journal Article
Open access
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ATAndreas Tassopoulos
Andreas Tassopoulos
Athanasios ChalkiasAthanasios Chalkias
Athanasios Chalkias
APAPOSTOLOS PAPALOIS
APOSTOLOS PAPALOIS
PKParaskevi Karlovasiti
Paraskevi Karlovasiti
JZJacopo Sergio Antonio Zanda
Jacopo Sergio Antonio Zanda
Theodoros XanthosTheodoros Xanthos
Theodoros Xanthos
Introduction and objectives Bacterial translocation (BT) is the passage of viable bacteria or endotoxins from the gastrointestinal lumen to extra-luminal tissues and is usually observed after intestinal ischaemia-reperfusion injury. The aim of this study was to investigate post-resuscitation BT after cardiac arrest and resuscitation in a swine anaesthetized with propofol-based total intravenous anaesthesia. Materials and methods Eighteen female Landrace/Large White piglets were randomly divided into control (CON), cardiac arrest (CA) and cardiac arrest-cardiopulmonary resuscitation (CA-CPR) groups. In the CON group, the animals were only monitored for two hours. In the CA group, the animals were not resuscitated and underwent necropsy immediately after cardiac arrest. In the CA-CPR group, the animals were resuscitated until the return of spontaneous circulation (ROSC) and were monitored for two hours. The animals of the CON and CA-CPR groups underwent necropsy 24 hours later. Bacterial translocation was assessed by blood and tissue cultures and endotoxin measurement in the portal and systemic circulation. Malondialdehyde content calculation and histological analysis of the intestine were performed in order to estimate ischemia and reperfusion (I/R) tissue damage. Results Malondialdehyde content, an indicator of oxidative stress, was significantly higher in the CA-CPR group compared to the CA in homogenized ileum (p=0.016). Malondialdehyde content in homogenized colon revealed significantly higher levels in the CA-CPR group compared to the CON (p=0.004) and the CA group (p=0.016). We found significantly higher levels of portal endotoxin in the CA-CPR group compared to the CON (p=0.026) and the CA group (p=0.026). The number of positive mesenteric lymph nodes cultures for E. coli was greater in the CA-CPR group, followed by the CA and CON groups, although the difference was not significant (67%, 33%, and 33%, respectively; p=0.407). Conclusions Malondialdehyde content and portal endotoxin levels do not increase during the cardiac arrest interval, but only after CPR and ROSC. Although the number of positive MLNs cultures was greater in the CA-CPR animals, no statistically significant differences were observed between the three groups due to the short monitoring period.

12 February 2024 in Diagnostics
Verified
Journal Article
Open access
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AKAntonella Koutela
Antonella Koutela
GLGeorge Loudos
George Loudos
MRMaritina Rouchota
Maritina Rouchota
Dimitris KletsasDimitris Kletsas
Dimitris Kletsas
AKAndreas Karameris
Andreas Karameris
APAPOSTOLOS PAPALOIS
APOSTOLOS PAPALOIS
Translational perspective: Ischemic heart disease remains a major medical problem with high mortality rates. Beside the great efforts devoted to research worldwide and the use of numerous experimental models, an absolute understanding of myocardial infarction and tissue loss has not yet been achieved. Furthermore, the regeneration of myocardial tissue and the improvement of myocardial activity after ischemia is one of the major areas of interest in the medical (and especially cardiovascular) community. In a novel experimental rat model, the beneficial effect of mesenchymal stem cell transplantation (MSCT) in a surgically induced ischemic myocardium was documented. From a clinical perspective, this work supports the surgical administration of MSCT in the infarcted area during coronary artery bypass surgery. Aims: The regeneration of myocardial tissue and the improvement of myocardial activity after ischemia is one of the major areas of interest in cardiovascular research. We developed a novel experimental rat model and used it to examine the effect of mesenchymal stem cell transplantation (MSCT) on myocardial ischemia evaluated by SPECT-CT and immunohistochemistry. Methods and results: An open thoracotomy took place for forty adult female Wistar rats with (n = 30) or without (n = 10) surgical ligation of the left anterior descending coronary artery (LAD) in order to cause myocardial ischemia. Myocardial viability was evaluated via SPECT/CT 7 days before surgery, as well as at 7 and 14 days post-surgery. At day 0, 15 animals received homologous stem cells injected at the ischemic myocardium area. A SPECT/CT evaluation showed decreased activity of the myocardial cells in the left ventricle one week post-infarction. Regeneration of the ischemic myocardium fifteen days post-infarction was recorded only in animals subjected to stem cell transplantation. These findings were also confirmed by histology and immunohistochemical analysis, with the significantly higher expression of GATA4 and Nkx2.5. Conclusions: The positive effect of mesenchymal stem cell transplantation in the ischemic myocardium was recorded. The application of SPECT-CT allowed a clear evaluation of both the quality and quantity of the living myocardium post-infarction, leading to a new approach in the research of cardiovascular diseases. From a clinical perspective, MSCT may be beneficial when accompanied by myocardial revascularization procedures.

7 September 2021 in Cureus
Verified
Journal Article
Open access
ADAlexandros Douvanas
Alexandros Douvanas
MKMaria Kalafati
Maria Kalafati
ETEleni Tamvaki
Eleni Tamvaki
ANAlexandra-Stavroula Nieri
Alexandra-Stavroula Nieri
APAPOSTOLOS PAPALOIS
APOSTOLOS PAPALOIS
EPElisavet Papathanasoglou
Elisavet Papathanasoglou
Severe and prolonged asphyxia can result in either intrauterine fetal death and stillbirth or multiorgan failure in surviving neonates. Establishing effective ventilation is the primary aim of resuscitation in newborns with asphyxia. The objective of this study was to compare the outcome of resuscitation by applying an endotracheal tube (ETT) with less, an ETT with moderate, and an ETT with high leakage during mechanical ventilation in swine neonates after prolonged perinatal asphyxia. A prospective, randomized controlled laboratory study was performed. Thirty Landrace/large white pigs, aged one to four days and weighted 1.754±218 gr, were randomly allocated into three groups depending on the ETT size: Group C (less leak: ETT no 4.0, n=10); Group A (high leak: ETT no 3.0, n=10); and Group B (moderate leak: ETT no 3.5, n=10). Mechanical asphyxia was performed until their heart rate was less than 60 bpm or their mean arterial pressure was below 15 mmHg. All animals with return of spontaneous circulation (ROSC) were monitored for four hours for their hemodynamic parameters, arterial oxygen saturation, and lactate acid levels. We demonstrate that 70% of the surviving animals were ventilated with an ETT with a leak (no. 3.5 and 3). A statistically significant difference was noted in PO2 (p=0.032) between Group B (126.4±53.4 mmHg) compared to Group A (72.28±29.18 mmHg) and Group C (94.28±20.46 mmHg) as well as in the right atrial pressure (p<0.001) between Group C (4.5 mmHg) vs Groups A (2 mmHg) and B (2 mmHg) during ROSC time. Lactate levels were statistically significantly lower (p=0.035) in Group C (mean=0.92 ± 0.07mmol/L) as compared to Group A (mean=1.13 ± 0.1 mmol/L) and Group B (mean= 1.08 ± 0.07 mmol /L; p = 0.034) at 4h post-ROSC. We provide preliminary evidence that ventilation with ETT with moderate leakage improves survival after 2h of ROSC, along with oxygenation and hemodynamic parameters, in a porcine model of neonatal asphyxia and resuscitation, compared to less leakage ETT.

21 December 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
AKAntonella Koutela
Antonella Koutela
GLGeorge Loudos
George Loudos
MRMaritina Rouchota
Maritina Rouchota
Dimitris KletsasDimitris Kletsas
Dimitris Kletsas
AKAndreas Karameris
Andreas Karameris
APAPOSTOLOS PAPALOIS
APOSTOLOS PAPALOIS
: Aims: Regeneration of myocardial tissue and improvement of myocardial activity after ischemia is one of the major fields of interest in cardiovascular research. We have developed a novel experimental rat model, and used it to examine the effect of mesenchymal stem cell transplantation (MSCT) on myocardial ischemia evaluated by single photon emission computed tomography (SPECT/CT) and immunohistochemistry. Methods and results: Forty adult female Wistar rats underwent open thoracotomy with (n=30) or without (n=10) surgical ligation of the left anterior descending coronary artery (LAD), to create myocardial ischemia, which was confirmed with ECG. Myocardial viability was evaluated via SPECT/CT at 7 days before as well as at 7 and 14 days post-surgery. At day 0, 15 animals received homologous stem cells injected at the ischemic myocardium area. SPECT/CT evaluation confirmed the reduction of functional myocardial cells of the left ventricle one week post-infarction. Regeneration of the ischemic myocardium fifteen days post infarction was recorded, only in animals submitted to stem cell transplantation. Findings were also confirmed by histology and immunohistochemical analysis, with significant higher expression of GATA4 and Nkx2,5. Conclusion: The positive effect of mesenchymal stem cells transplantation in the ischemic myocardium was recorded. The application of SPECT- CT qualitative and quantitative evaluation of myocardial function may lead to a new approach in experimentation with an anticipated significant impact in the ongoing cardiovascular laboratory research. In clinical perspective, MSCT may be beneficial when accompanied with myocardial revascularization procedures.

30 December 2023 in Medicina
Verified
Journal Article
Open access
PDF file
POPanagoula Oikonomou
Panagoula Oikonomou
CNChristina Nikolaou Nikolaou
Christina Nikolaou Nikolaou
FPFotini Papachristou
Fotini Papachristou
ASApostolos Sovatzidis
Apostolos Sovatzidis
MLMARIA LAMBROPOULOU
MARIA LAMBROPOULOU
ATAlexandra K Tsaroucha
Alexandra K Tsaroucha
Background and Objectives: Inflammation and dysregulation in the intestinal barrier function in acute pancreatitis (AP) trigger pancreatic lesions, systemic inflammatory response, and multiple organ dysfunction. Eugenol, as the main component of clove (Syzygium aromaticum), is known for its antioxidant and anti-inflammatory properties. We studied the potentially beneficial effect of eugenol in a rodent model of biliopancreatic duct ligation-induced AP. Materials and Methods: Rats were randomly divided into three groups: Sham, AP, and AP + eugenol (15 mg/kg/day). Serum TNFα, IL-6, IL-18, and resistin levels, as well as IL-6, TNFα, MPO, HMGB1, and CD45 tissue expression, were determined at various timepoints after the induction of AP. Results: Eugenol attenuated hyperemia and inflammatory cell infiltration in the intestinal mucosal, submucosal, and muscular layers. IL-6 and resistin serum levels were significantly reduced in the AP + eugenol group, while serum TNFα and IL-18 levels remained unaffected overall. TNFα pancreatic and intestinal expression was attenuated by eugenol at 72 h, while IL-6 expression was affected only in the pancreas. MPO, CD45, and HMGB1 intestinal expression was significantly reduced in eugenol-treated rats. Conclusions: Eugenol managed to attenuate the inflammatory response in the intestine in duct ligation-induced AP in rats.