Ioannis Papaconstantinou

Prof. Dr. Ioannis Papaconstantinou

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Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

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

Representative Publications

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27 May 2024 in Nutrients
Verified
Journal Article
Open access
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John K. TriantafillidisJohn K. Triantafillidis
John K. Triantafillidis
IPIoannis Papaconstantinou
Ioannis Papaconstantinou
Pantelis AntonakisPantelis Antonakis
Pantelis Antonakis
MKManousos M. Konstadoulakis
Manousos M. Konstadoulakis
APOSTOLOS E. PAPALOISAPOSTOLOS E. PAPALOIS
APOSTOLOS E. PAPALOIS
It is well established that the preoperative nutritional status of gastric cancer (GC) patients significantly affects the prognosis of the operated patients, their overall survival, as well as the disease-specific survival. Existing data support that preoperative assessment of nutritional status and early correction of nutritional deficiencies exert a favorable effect on early postoperative outcomes. A variety of relevant indices are used to assess the nutritional status of GC patients who are candidates for surgery. The guidelines of almost all international organizations recommend the use of oral enteral nutrition (EN). Oncologically acceptable types of gastrectomy and methods of patient rehabilitation should take into account the expected postoperative nutritional status. The majority of data support that perioperative EN reduces complications and hospital stay, but not mortality. Oral EN in the postoperative period, albeit in small amounts, helps to reduce the weight loss that is a consequence of gastrectomy. Iron deficiency with or without anemia and low serum levels of vitamin B12 are common metabolic sequelae after gastrectomy and should be restored. EN also significantly helps patients undergoing neoadjuvant or adjuvant antineoplastic therapy. The occurrence of the so-called “postgastrectomy syndromes” requires dietary modifications and drug support. This review attempts to highlight the benefits of EN in GC patients undergoing gastrectomy and to emphasize the type of necessary nutritional management, based on current literature data.

1 March 2012 in European Journal of Gastroenterology & Hepatology
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Journal Article
Closed access
IPIoannis Papaconstantinou
Ioannis Papaconstantinou
AKAndreas Karakatsanis
Andreas Karakatsanis
MGMaria Gazouli
Maria Gazouli
GPGeorge Polymeneas
George Polymeneas
DVDionissios Voros
Dionissios Voros
Hepatocellular carcinoma and cholangiocarcinoma constitute the majority of primary malignant tumors located in the liver, with hepatocellular carcinoma accounting for approximately 80% of these tumors and cholangiocarcinoma representing the remaining 20%. Both are aggressive malignancies, heterogeneous in terms of biological activities and clinical behavior, with dismal outcomes and an increasing incidence worldwide. Radical surgical resection remains the gold standard to date, as adjuvant therapeutic modalities have failed to show a consistent and adequate curative response. However, radical surgical resection is not feasible in most of the patients with such tumors, as tumor size or functional status of the parenchyma does not permit extended hepatic resection. In addition, patients who undergo curative resection often have a high rate of relapse. Multimodal therapeutic approaches, such as the combination of invasive methods (surgical resection, radiofrequency ablation, and two-step or three-step procedures with intermittent portal vein embolization) with interferon-α, systemic chemotherapy, or transarterial catheter embolization, may prolong survival in some patients, but have, however, failed to demonstrate satisfactory results. Therefore, an obvious need emerges for the discovery of new biomarkers to understand the events leading to hepatocarcinogenesis, to relate different phenotypes with differences in clinical behavior and prognosis, and, if possible, to predict response rates to adjuvant therapeutic modalities or, furthermore, to establish novel mechanism-based treatments for hepatic tumors.

31 October 2020 in Journal of Clinical Medicine
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Journal Article
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Mariangela AlloccaMariangela Allocca
Mariangela Allocca
MCMaría Chaparro
María Chaparro
HGHaidee Aleman Gonzalez
Haidee Aleman Gonzalez
MBMarta Maia Bosca-Watts
Marta Maia Bosca-Watts
CPCarolina Palmela
Carolina Palmela
GFGionata Fiorino
Gionata Fiorino
The impact of COVID-19 on inflammatory bowel disease (IBD) patients under pharmacological immunosuppression is still not clearly understood. We investigated the incidence of COVID-19 and the impact of immunosuppression and containment measures on the risk of SARS-CoV-2 infection in a large IBD cohort, from a multicenter cohort from 21st of February to 30th of June, 2020. Ninety-seven patients with IBD (43 UC, 53 CD, one unclassified IBD) and concomitant COVID-19 over a total of 23,879 patients with IBD were enrolled in the study. The cumulative incidence of SARS-CoV-2 infection in patients with IBD vs. the general population was 0.406% and 0.402% cases, respectively. Twenty-three patients (24%) were hospitalized, 21 (22%) had pneumonia, four (4%) were admitted to the Intensive Care Unit, and one patient died. Lethality in our cohort was 1% compared to 9% in the general population. At multivariable analysis, age > 65 years was associated with increased risk of pneumonia and hospitalization (OR 11.6, 95% CI 2.18–62.60; OR 5.1, 95% CI 1.10–23.86, respectively), treatment with corticosteroids increased the risk of hospitalization (OR 7.6, 95% CI 1.48–40.05), whereas monoclonal antibodies were associated with reduced risk of pneumonia and hospitalization (OR 0.1, 95% CI 0.04–0.52; OR 0.3, 95% CI 0.10–0.90, respectively). The risk of COVID-19 in patients with IBD is similar to the general population. National lockdown was effective in preventing infection in our cohort. Advanced age and treatment with corticosteroids impacted negatively on the outcome of COVID-19, whereas monoclonal antibodies did not seem to have a detrimental effect.

20 May 2004 in Artificial Organs
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Journal Article
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GZGeorge Zavos
George Zavos
JBJohn Bokos
John Bokos
IPIoannis Papaconstantinou
Ioannis Papaconstantinou
JBJohn Boletis
John Boletis
MGMaria Gazouli
Maria Gazouli
AKAlkiviadis Kostakis
Alkiviadis Kostakis

30 September 2019 in Vascular Specialist International
Verified
Journal Article
Open access
TKThomas Kotsis
Thomas Kotsis
BSBasileios Georgiou Spyropoulos
Basileios Georgiou Spyropoulos
NANikolaos Asaloumidis
Nikolaos Asaloumidis
PCPanagitsa Christoforou
Panagitsa Christoforou
KKKonstantina Katseni
Konstantina Katseni
IPIoannis Papaconstantinou
Ioannis Papaconstantinou
Penetrating atherosclerotic ulcers (PAUs) of the aorta are defined as atherosclerotic lesions with aortic intima and media ulceration, which may lead to a complete rupture of the adventitial wall. The present article aimed to report an unusual case of a surgically treated patient with abdominal aorta PAU with an illustration of the key features and to review and analyze the existing literature data. PAUs typically develop in elderly and hypertensive patients and in patients with advanced atherosclerosis. Although originally described for the descending thoracic aorta, a similar clinicopathological entity also occurs in the abdominal aorta. Patients with symptoms of a PAU should be treated immediately if they are fit for surgery. Exceptive observation by imaging modalities is necessary in patients with asymptomatic small (<2 cm) PAU, with or without focal dissection.

21 August 2007 in World Journal of Surgical Oncology
Verified
Journal Article
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PEPapalambros Efstathios
Papalambros Efstathios
PAPetrou Athanasios
Petrou Athanasios
IPIoannis Papaconstantinou
Ioannis Papaconstantinou
PAPapalambros Alexandros
Papalambros Alexandros
SFSigala Frangisca
Sigala Frangisca
GAGiannopoulos Athanasios
Giannopoulos Athanasios
Background: Gastrointestinal stromal tumors (GIST) represent the most common mesenchymal tumors of the digestive tract. Over the last ten years the management of GISTs has dramatically altered but their coexistence with other gasrointesinal tumors of different histogenesis presents a special interest. The coexistence of GISTs with other primaries is usually discovered incidentally during GI surgery for carcinomas. Case presentation: We present here, a case of a 66-year-old patient with intestinal GIST and a synchronous colorectal adenocarcinoma discovered incidentally during surgical treatment of the recurrent GIST. Immunohistochemical examination revealed the concurrence of histologically proved GIST (strongly positive staining for c-kit, vimentin, SMA, and focal positive in S-100, while CD-34 was negative) and Dukes Stage C, (T3, N3, M0 according the TNM staging classification of colorectal cancer). Conclusion: The coexistence of GIST with either synchronous or metachronous colorectal cancer represents a phenomenon with increasing number of relative reports in the literature the last 5 years. In any case of GIST the surgeon should be alert to recognize a possible coexistent tumor with different histological origin and to perform a thorough preoperative and intraoperative control. The correct diagnosis before and at the time of the surgical procedure is the cornerstone that secures the patients' best prognosis.