Theodoros Pittaras

Dr. Theodoros Pittaras

orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

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

Representative Publications

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30 January 2022 in Nutrients
Verified
Journal Article
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John K. TriantafillidisJohn K. Triantafillidis
John K. Triantafillidis
ETEleni Triantafyllidi
Eleni Triantafyllidi
MSMichail Sideris
Michail Sideris
TPTheodoros Pittaras
Theodoros Pittaras
APOSTOLOS E. PAPALOISAPOSTOLOS E. PAPALOIS
APOSTOLOS E. PAPALOIS
Background: Pancreatic cancer represents the most lethal malignancy among all digestive cancers. Despite the therapeutic advances achieved during recent years, the prognosis of this neoplasm remains disappointing. An enormous amount of experimental (mainly) and clinical research has recently emerged referring to the effectiveness of various plants administered either alone or in combination with chemotherapeutic agents. Apart from Asian countries, the use of these plants and herbals in the treatment of digestive cancer is also increasing in a number of Western countries as well. The aim of this study is to review the available literature regarding the efficacy of plants and herbals in pancreatic cancer. Methods: The authors have reviewed all the experimental and clinical studies published in Medline and Embase, up to June 2021. Results: More than 100 plants and herbals were thoroughly investigated. Favorable effects concerning the inhibition of cancer cell lines in the experimental studies and a favorable clinical outcome after combining various plants with established chemotherapeutic agents were observed. These herbals and plants exerted their activity against pancreatic cancer via a number of mechanisms. The number and severity of side-effects are generally of a mild degree. Conclusion: A quite high number of clinical and experimental studies confirmed the beneficial effect of many plants and herbals in pancreatic cancer. More large, double-blind clinical studies assessing these natural products, either alone or in combination with chemotherapeutic agents should be conducted.

27 August 2014 in Virology Journal
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Journal Article
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MPMarianna Politou
Marianna Politou
DKDimitrios Koutras
Dimitrios Koutras
GKGeorge Karlis
George Karlis
SVSERENA VALSAMI
SERENA VALSAMI
TPTheodoros Pittaras
Theodoros Pittaras
EKEvangelia Kouskouni
Evangelia Kouskouni
Herpes viruses infection transmitted through healthy but infected blood donors pose a danger to herpes-naive immunocompromised recipients. The risk of transfusion-related HHV-8 transmission is different in endemic and not endemic areas. HHV-6 and HHV-8 seroprevalence and viral load among blood donors have been reported from different countries. The aim of our study was to assess the seroprevalence of HHV-8 and HHV-6 in volunteer blood donors from Greece which is unknown. Serum samples from 179 healthy blood donors were tested for the presence of IgG antibodies against HHV-6 and HHV-8 with ELISA. None of the 179 donors of Greek origin tested was positive for HHV-8. HHV-6 seropositivity was assessed in 160 blood donors’ samples and was found to be 78.75% (126/160). The HHV-6 seroprevalence did not differ either between males and females or among different decade age groups. The fact, that no blood donor was positive for HHV-8 IgG antibodies indicates that the risk for transfusion related HHV-8 transmission in Greece, if any, is negligible and does not warrant broad testing for HHV-8. Definitely further studies are needed, in order to clarify the potential risk of HHV-6 transmission.

20 May 2024 in Cancers
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Anastasios G. KriebardisAnastasios G. Kriebardis
Anastasios G. Kriebardis
LCLeonidas Chardalias
Leonidas Chardalias
Christos DamaskosChristos Damaskos
Christos Damaskos
APAbraham Pouliakis
Abraham Pouliakis
Nikolaos GarmpisNikolaos Garmpis
Nikolaos Garmpis
SVSERENA VALSAMI
SERENA VALSAMI
Background: The release of microvesicles (MVs) is an essential phenomenon for inter-cellular signaling in health and disease. The role of MVs in cancer is multidimensional and includes cancer cell survival, proliferation, and invasion. In this prospective study, we analyzed MV levels in colorectal cancer patients and assessed the importance of MV release in early-stage colorectal cancer and survival. Methods: This study included 98 patients and 15 controls. The characterization of MVs from human plasma was performed by flow cytometry using monoclonal antibodies. Results: The levels of total MVs and MUC-1-positive, tissue factor (TF)-positive, and endothelial cell-derived MVs (EMVs) were statistically significantly higher in the colon cancer patients than in the controls (p < 0.001). Furthermore, the subgroup of patients with very early-stage colorectal cancer also had statistically significant differences in the levels of the abovementioned MVs compared to the controls (p < 0.01). Highly differentiated tumors had lower levels of MUC-1-positive MVs (p < 0.02), EMVs (p < 0.002), and EMV/TF combinations (p < 0.001) versus those with tumors with low/intermediate differentiation. Conclusions: Our data demonstrate that the analysis of circulating MV levels in plasma could possibly become a tool for the early diagnosis of colon cancer at a very early stage of the disease.

Verified
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SFSotirios P. Fortis
Sotirios P. Fortis
SKStyliani Kokoris
Styliani Kokoris
PKPavlos Kelepousidis
Pavlos Kelepousidis
GDGEORGIOS DRYLLIS
GEORGIOS DRYLLIS
MKMaria-Aspasia G. Kosma
Maria-Aspasia G. Kosma
SVSERENA VALSAMI
SERENA VALSAMI
Background: Biological sex differences are well-recognized as non-negligible factors in implementing precision medicine practice. Sex chromosomes influence protein expression and signaling, and thus cellular pathways are often regulated differently. Additionally, the importance of sex as a biological variable has gained significant traction in biomedical research, including transfusion medicine. Regarding transfusion medicine, several studies reveal the role of gender in blood transfusion, blood donors’ behavior towards donation, blood products’ composition and storage, transfusion therapy, and possibly post-transfusion patient outcomes. Methods: In this review, the role of sex and gender in the whole transfusion chain (from the blood donor to the blood product and the patient) is assessed and summarized using data from observational studies, registry analyses, and randomized trials. Results: Female donors face higher deferral rates due to biological factors (iron deficiency, low hemoglobin, pregnancy) and sociocultural factors (caregiving responsibilities, misinformation). However, women are more likely to donate based on empathy, moral duty, or community responsibility and are more consistent in sustaining voluntary donation during crises. Men donate more frequently, typically driven by external motivators, and provide red blood cell (RBC) products with higher hemoglobin content, whereas RBCs from female donors exhibit greater metabolic stability and reduced hemolysis during storage. Plasma from multiparous women possibly contains alloantibodies associated with adverse transfusion reactions, namely transfusion-related acute lung injury (TRALI). Platelet function also varies by sex, though its possible clinical impact is still unknown. Although observational studies suggest sex-mismatched transfusions are associated with increased morbidity and mortality—particularly in transfusions from female donors to male recipients—large registries and randomized controlled trials show inconsistent or negligible effect on survival. Conclusions: Donor and recipient sex are emerging variables of possible clinical importance in transfusion practice. Incorporating sex-informed insights into donor recruitment, blood product handling and transfusion policies may improve safety while advancing precision medicine. Further large-scale trials are needed to elucidate the impact of sex in transfusion, identify and eliminate possible risks, and bridge the gap between biological insights and clinical practice.

21 September 2024 in Journal of Clinical Medicine
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Journal Article
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DPDimitrios Dorotheos Papadakis
Dimitrios Dorotheos Papadakis
MPMarianna Politou
Marianna Politou
TPTheodoros Pittaras
Theodoros Pittaras
ISIoanna STERGIOU
Ioanna STERGIOU
AKAntonia Koutsoukou
Antonia Koutsoukou
IVIoannis Vasileiadis
Ioannis Vasileiadis
Background/Objectives: Through the past several years, a constant interaction has been implicated between complement and coagulation cascades. SARS-CoV-2 infection and bacterial sepsis are potent activators of both cascades. This study aims to compare the extent of complement and intrinsic coagulation pathway activation (and the interplay between them) among patients with COVID-19 and bacterial sepsis. Methods: Serum and plasma samples were collected from 25 ICU patients (11 patients with COVID-19 and 14 patients with bacterial sepsis) at two time points (on admission and either on improvement or deterioration). The activities of coagulation factors XI and XII and complement factors C3a and C5a were measured at both time points. Results: The activities of factors XI and XII were increased in both groups of patients and at both time points. However, there were no statistically significant differences between SARS-CoV-2 and bacterial sepsis patients. On the other hand, both C3a and C5a were significantly higher in the COVID-19 group on admission. This correlation was preserved on reassessment. Conclusions: Complement activation seems to be more enhanced in COVID-19 than bacterial sepsis. However, the lack of statistical significance in factors XI and XII indicates t the presence of additional pathways for complement activation in SARS-CoV-2 infection.

Verified
Journal Article
Open access
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John K. TriantafillidisJohn K. Triantafillidis
John K. Triantafillidis
AMARETI MANIOTI
ARETI MANIOTI
TPTheodoros Pittaras
Theodoros Pittaras
TKTheodoros Ioannis Kozonis
Theodoros Ioannis Kozonis
EKEmmanouil Kritsotakis
Emmanouil Kritsotakis
APOSTOLOS E. PAPALOISAPOSTOLOS E. PAPALOIS
APOSTOLOS E. PAPALOIS
Background: The long-term clinical and laboratory results of a 33-year follow-up of a Greek family with abetalipoproteinemia (ABL) are described. Case Report: The patients (two brothers and their sister, aged 57, 49, and 62 years, respectively) are still alive, being under close surveillance. In two of the three patients, diarrhea appeared in early infancy, while in the third, it appeared during adolescence. CNS symptomatology worsened after the second decade of life. At the same time, night blindness appeared in the advanced stages of the disease, resulting in almost complete loss of vision in one of the male patients and severe impairment in the other. The diagnosis was based on the clinical picture, ophthalmological findings, serum lipid estimations, and presence of peripheral acanthocytosis. All patients exhibited typical serum lipidemic profile, ophthalmological findings, and acanthocytes in the peripheral blood. During the follow-up period, strict dietary modifications were applied, including the substitution of fat with medium-chain triglycerides (MCT oil). After 33 years since the initial diagnosis, all patients are alive without any sign of liver dysfunction despite continuous use of MCT oil. However, symptoms from the central nervous system and vision impairment worsened. Conclusion: The course of these patients suggests that the application of a modified diet, including MCT oil, along with close surveillance, could prolong the survival of patients without significant side effects from the liver.