Helen Dimitriou

Dr. Helen Dimitriou


Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

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

Representative Publications

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1 March 2013 in BMC Pediatrics
Verified
Journal Article
Open access
PDF file
DFDiana-Michaela Fitrolaki
Diana-Michaela Fitrolaki
HDHelen Dimitriou
Helen Dimitriou
MKMaria Kalmanti
Maria Kalmanti
GBGeorge Briassoulis
George Briassoulis
Background: Critical illness constitutes a serious derangement of metabolism. The aim of our study was to compare acute phase metabolic patterns in children with sepsis (S) or severe sepsis/septic shock (SS) to those with severe traumatic brain injury (TBI) and healthy controls (C) and to evaluate their relations to neutrophil, lymphocyte and monocyte expressions of CD64 and CD11b. Methods: Sixty children were enrolled in the study. Forty-five children with systemic inflammatory response syndrome (SIRS) were classified into three groups: TBI (n = 15), S (n = 15), and SS (n = 15). C consisted of 15 non- SIRS patients undergoing screening tests for minor elective surgery. Blood samples were collected within 6 hours after admission for flow cytometry of neutrophil, lymphocyte and monocyte expression of CD64 and CD11b (n = 60). Procalcitonin (PCT), C-reactive protein (CRP), glucose, triglycerides (TG), total cholesterol (TC), high (HDL) or low-density-lipoproteins (LDL) were also determined in all groups, and repeated on day 2 and 3 in the 3 SIRS groups (n = 150). Results: CRP, PCT and TG (p < 0.01) were significantly increased in S and SS compared to TBI and C; glucose did not differ among critically ill groups. Significantly lower were the levels of TC, LDL, and HDL in septic groups compared to C and to moderate changes in TBI (p < 0.0001) but only LDL differed between S and SS (p < 0.02). Among septic patients, PCT levels declined significantly (p < 0.02) with time, followed by parallel decrease of HDL (p < 0.03) and increase of TG (p < 0.02) in the SS group. Neutrophil CD64 (nCD64) expression was higher in patients with SS (81.2%) and S (78.8%) as compared to those with TBI (5.5%) or C (0.9%, p < 0.0001). nCD64 was positively related with CRP, PCT, glucose, and TG (p < 0.01) and negatively with TC, LDL, and HDL (p < 0.0001), but not with severity of illness, hematologic indices, length of stay or mechanical ventilation duration. Conclusions: In sepsis, the early stress-metabolic pattern is characterized by a high (nCD64, glucose, TG) - low (TC, HDL, LDL) combination in contrast to the moderate pattern of TBI in which only glucose increases combined with a moderate cholesterol - lipoprotein decrease. These early metabolic patterns persist the first 3 days of acute illness and are associated with the acute phase CD64 expression on neutrophils.

25 January 2022 in Antioxidants
Verified
Journal Article
Open access
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MMMarianna Miliaraki
Marianna Miliaraki
PBPanayiotis Briassoulis
Panayiotis Briassoulis
Stavroula IliaStavroula Ilia
Stavroula Ilia
KMKalliopi Michalakakou
Kalliopi Michalakakou
TKTheodoros Karakonstantakis
Theodoros Karakonstantakis
GBGeorge Briassoulis
George Briassoulis
Oxidative stress is considered pivotal in the pathophysiology of sepsis. Oxidants modulate heat shock proteins (Hsp), interleukins (IL), and cell death pathways, including apoptosis. This multicenter prospective observational study was designed to ascertain whether an oxidant/antioxidant imbalance is an independent sepsis discriminator and mortality predictor in intensive care unit (ICU) patients with sepsis (n = 145), compared to non-infectious critically ill patients (n = 112) and healthy individuals (n = 89). Serum total oxidative status (TOS) and total antioxidant capacity (TAC) were measured by photometric testing. IL-6, -8, -10, -27, Hsp72/90 (ELISA), and selected antioxidant biomolecules (Ζn, glutathione) were correlated with apoptotic mediators (caspase-3, capsase-9) and the central anti-apoptotic survivin protein (ELISA, real-time PCR). A wide scattering of TOS, TAC, and TOS/TAC in all three groups was demonstrated. Septic patients had an elevated TOS/TAC, compared to non-infectious critically ill patients and healthy individuals (p = 0.001). TOS/TAC was associated with severity scores, procalcitonin, IL-6, -10, -27, IFN-γ, Hsp72, Hsp90, survivin protein, and survivin isoforms -2B, -ΔΕx3, -WT (p < 0.001). In a propensity probability (age-sex-adjusted) logistic regression model, only sepsis was independently associated with TOS/TAC (Exp(B) 25.4, p < 0.001). The AUCTOS/TAC (0.96 (95% CI = 0.93–0.99)) was higher than AUCTAC (z = 20, p < 0.001) or AUCTOS (z = 3.1, p = 0.002) in distinguishing sepsis. TOS/TAC, TOS, survivin isoforms -WT and -2B, Hsp90, IL-6, survivin protein, and repressed TAC were strong predictors of mortality (p < 0.01). Oxidant/antioxidant status is impaired in septic compared to critically ill patients with trauma or surgery and is related to anti-apoptotic, inflammatory, and innate immunity alterations. The unpredicted TOS/TAC imbalance might be related to undefined phenotypes in patients and healthy individuals.

1 January 2008 in Cytotherapy
Verified
Journal Article
Closed access
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HDHelen Dimitriou
Helen Dimitriou
ELE. Linardakis
E. Linardakis
GMG. Martimianaki
G. Martimianaki
ESE. Stiakaki
E. Stiakaki
CPC.H. Perdikogianni
C.H. Perdikogianni
MKM. Kalmanti
M. Kalmanti
Mesenchymal stromal cells (MSC) have become the focus of cellular therapeutics but little is known regarding bone marrow (BM) MSC derived from children. As MSC constitute part of BM stroma, we examined their properties in children with hematologic diseases. BM MSC from children with non-malignant hematologic disorders and acute lymphoblastic leukemia (ALL) were isolated and expanded. MSC were immunophenotypically characterized and their functional characteristics were assessed by CFU-F assay and cell doubling time calculation. Their ability for trilineage differentiation was verified by molecular and histochemical methods. Apoptosis was evaluated and clonal analysis was performed. MSC were isolated from BM of all groups. They acquired the mesenchymal-related markers from the first passage, with a simultaneous decrease of hematopoietic markers. A very low percentage of apoptotic cells was detected in all passages. The proliferative and clonogenic capacity did not differ among groups, with the exception of ALL at diagnosis, in which they were defective. Histochemical and molecular analysis of differentiated MSC yielded characteristics for adipocytes, osteoblasts and chondrocytes. Clonal analysis in a number of BM samples revealed a highly heterogeneous population of cells within each clone. MSC from BM of children with hematologic disorders, with the exception of ALL at diagnosis, can be isolated in sufficient number and quality to serve as a potential source for clinical applications.

24 April 2015 in Cell Biology International
Verified
Journal Article
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IPIordanis Pelagiadis
Iordanis Pelagiadis
ESEftichia Stiakaki
Eftichia Stiakaki
CCChristianna Choulaki
Christianna Choulaki
MKMaria Kalmanti
Maria Kalmanti
HDHelen Dimitriou
Helen Dimitriou

28 April 2009 in Cell Proliferation
Verified
Journal Article
Closed access
PDF file
HDHelen Dimitriou
Helen Dimitriou
CPCh. Perdikogianni
Ch. Perdikogianni
GMG. Martimianaki
G. Martimianaki
DCD. M. Choumerianou
D. M. Choumerianou
JPJ. Pelagiadis
J. Pelagiadis
MKM. Kalmanti
M. Kalmanti

1 August 2022 in Frontiers in Public Health
Verified
Journal Article
Open access
GGGeorgios Galanos
Georgios Galanos
HDHelen Dimitriou
Helen Dimitriou
APAngelos Pappas
Angelos Pappas
CPChrysoula Perdikogianni
Chrysoula Perdikogianni
ESEmmanouil K. Symvoulakis
Emmanouil K. Symvoulakis
Christos LionisChristos Lionis
Christos Lionis
Background: Increased morbidity/mortality due to vaccine preventable diseases (VPD) is encountered in type 2 diabetes (T2D) people. Aim of this study was to assess their vaccination coverage and describe trends possibly affecting compliance.Methods: Information on vaccination coverage was retrieved from either documents or interview provided by patients, and/or their vaccination record card at a specialized outpatient diabetes center. The selection of the patients was arbitrary.Results: An increasing vaccination rate for influenza was observed from 2018 to 2020 among 372 participants. The vaccination coverage for S.pneumoniae was 67.2% (PCV13), 20.4% (PPSV23), 26.3% for herpes zoster in individuals ≥60 years, 1.9% for tetanus-diphtheria-pertussis and 1.1% for hepatitis B. A 10.2% of participants were found to be unvaccinated. Vaccination uptake for influenza and PCV13 was related to age, ≥3 comorbidities and long-term follow-up. T2D individuals consecutively vaccinated for influenza were 3.78 times more likely to be also vaccinated with PCV13.Conclusions: Vaccination rates of patients with T2D show an increasing trend, especially for influenza and S. pneumoniae, although the one for S. pneumoniae was low. Older people seem more prone to vaccination, the one for herpes zoster was low with infected patients remaining unvaccinated while significantly low coverage was observed for other VPDs. The findings are important to improve effectiveness of preventative services.