Georgios Petrakis

Dr. Georgios Petrakis

Aristotle University of Thessaloniki, Thessaloníki, Kentrikí Makedonía, Greece
orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

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

Representative Publications

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1 May 2018 in The Lancet Infectious Diseases
Verified
Journal Article
Open access
ABAneel Bhangu
Aneel Bhangu
AAAdesoji O Ademuyiwa
Adesoji O Ademuyiwa
MAMaria Lorena Aguilera
Maria Lorena Aguilera
PAPhilip Alexander
Philip Alexander
SASara W Al-Saqqa
Sara W Al-Saqqa
RBRuth Blanco
Ruth Blanco
Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p<0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05-2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p<0·001). Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication. DFID-MRC-Wellcome Trust Joint Global Health Trial Development Grant, National Institute of Health Research Global Health Research Unit Grant.

Verified
Journal Article
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GTGeorgios Tzikos
Georgios Tzikos
IAIoannis Alexiou
Ioannis Alexiou
STSokratis Tsagkaropoulos
Sokratis Tsagkaropoulos
AMAlexandra Eleftheria Menni
Alexandra Eleftheria Menni
GCGeorgios Chatziantoniou
Georgios Chatziantoniou
Katerina KotzampassiKaterina Kotzampassi
Katerina Kotzampassi
Background: Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are widely accepted indices positively correlated with disease severity, progression, and mortality. In this study, we tested whether NLR and PLR could predict mortality and length of hospital stay (LOS) after cardiac surgery. Methods: NLR and PLR were calculated on days 0, 3, 5, and 7 postoperatively. A ROC curve was generated to assess their prognostic value; multivariate logistic analysis identified independent risk factors for 90-day mortality. Results: Analysis was performed on 179 patients’ data, 11 of whom (6.15%) died within 90 days. The discriminatory performance for predicting 90-day mortality was better for NLR7 (AUC = 0.925, 95% CI:0.865–0.984) with the optimal cut-off point being 7.10. NLR5 and PLR3 also exhibited a significant strong discriminative performance. Similarly, a significant discriminative performance was prominent for PLR3, NLR5, and NLR7 with respect to LOS. Moreover, NLR7 (OR: 2.143, 95% CI: 1.076–4.267, p = 0.030) and ICU LOS (OR:1.361, 95% CI: 1.045–1.774, p = 0.022) were significant independent risk factors for 90-day mortality. Conclusions: NLR and PLR are efficient predictive factors for 90-day mortality and LOS in cardiac surgery patients. Owing to the simplicity of determining NLR and PLR, their postoperative monitoring may offer a reliable predictor of patients’ outcomes in terms of LOS and mortality.

2 August 2024 in Nutrients
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Journal Article
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ITIoannis M. Theodorou
Ioannis M. Theodorou
DKDorothea Kapoukranidou
Dorothea Kapoukranidou
MTMARKOS IOANNIS THEODOROU
MARKOS IOANNIS THEODOROU
ITIoulia Tseti
Ioulia Tseti
AMAlexandra Eleftheria Menni
Alexandra Eleftheria Menni
Katerina KotzampassiKaterina Kotzampassi
Katerina Kotzampassi
The skin serves as a critical barrier against external threats—dehydration, ultraviolet exposure, and infections—playing a significant role in internal homeostasis and moisture retention. Additionally, and equally importantly, it interacts dynamically with the complex microbiome resident in it, which is essential for maintaining skin health. Recent interest has focused on the use of probiotics and postbiotics, besides their ability to modulate the skin microbiome, to enhance barrier function, and exhibit anti-inflammatory properties, to be involved in skincare, by having the potential to improve skin hydration, elasticity, and overall appearance, as well as in reducing signs of aging, such as wrinkles and fine lines. The products—being a combination of a cosmetic regime plus probiotic[s] or postbiotic[s]—are named cosmeceuticals. However, to comply with the regulations for the characterization of a microorganism as a specific probiotic strain, the pro- or postbiotics incorporated into the cosmetic regime should be both genetically and phenotypically defined. Thus, in this review, we present 14 published clinical trials using such cosmetic products with specific, well-characterized strains of probiotics or postbiotics applied to volunteers with healthy skin. Looking at the results of these studies collectively, we can say that these genetically and phenotypically defined strains of either live or inanimate bacteria and/or their components seem to keep the treated skin at least fully hydrated, with intact epithelial tone, increased radiance, and with decreased wrinkle depth, while normalizing the commensal skin microbiota. Future advancements in personalized skin care may lead to genomic sequencing and metabolomics to tailor probiotic and postbiotic treatments to individual skin microbiomes, promising a new frontier in cosmeceuticals.

7 August 2023 in Thyroid®
Verified
Journal Article
Closed access
ACAngeliki Chorti
Angeliki Chorti
VBVangelis Bontinis
Vangelis Bontinis
GTGeorgios Tzikos
Georgios Tzikos
ABAlkis Bontinis
Alkis Bontinis
AIAristeidis Ioannidis
Aristeidis Ioannidis
Theodosios S PapavramidisTheodosios S Papavramidis
Theodosios S Papavramidis
Background: Image-guided thermal ablation interventions are novel thermal-based modalities used for the treatment of benign thyroid nodules. Methods: We conducted a systematic review and a Bayesian network meta-analysis, examining studies using thermal ablation interventions in the treatment of benign nodular thyroid disease (PROSPERO CRD42022367680). The primary endpoints included volume reduction rate (VRR), and symptomatic score and cosmetic score improvement. Secondary endpoints included vocal disturbances, laryngeal nerve palsy, hypothyroidism, and nodular regrowth (defined by increased nodular volume of >50% for thermal ablation or new nodules arising in remaining thyroid tissue conventional surgery [CS]). Results: We included 16 studies (3 randomized controlled trials [RCTs] and 13 comparative case series), describing radiofrequency ablation (RFA), laser ablation (LA), microwave ablation (MWA), high-intensity focus ultrasound (HIFU), and CS, respectively. The review included data from 4112 patients followed for a mean of 11.9 months. Meta-analyses showed no significant differences among RFA, LA, MWA, HIFU, and CS regarding any of the primary endpoints of VRR, symptomatic score, and cosmetic score. In examining the surface under the cumulative ranking area (SUCRA) ranking, CS (SUCRA, 98.49), LA (SUCRA, 51.58), and MWA (SUCRA, 57.0) were identified as the three interventions that were most likely to result in the largest VRR, symptomatic and cosmetic score reduction. RFA, relative risk (RR) 0.19 [95% credibility interval (CI): 0.06 to 0.48], LA RR 0.23 [CI: 0.06 to 0.79], and MWA RR 0.25 [CI: 0.09 to 0.60] were associated with the greatest reduction in risk for postintervention vocal complications compared with CS, with RFA (SUCRA, 61.62) being ranked as the highest in safety. RFA RR 0.05 [CI: 0.00 to 0.40] and MWA RR 0.16 [CI: 0.02 to 0.73] were associated with a reduced risk of transient laryngeal nerve injury compared with CS. RFA RR 0.00 [CI: 0.00 to 0.00] and MWA RR 0.00 [CI: 0.00 to 0.03] were associated with a reduced risk of hypothyroidism occurrence compared with CS, with RFA (SUCRA, 99.86) yielding the highest safety ranking. RFA was associated with a reduced risk for nodular regrowth RR 0.09 [CI: 0.00 to 0.85], compared with CS. Conclusion: We have comprehensively reviewed the published literature on the efficacy and safety of thermal ablation modalities for benign thyroid nodules. Important research gaps remain regarding a paucity of both long-term data and high-quality RCTs.

24 June 2022 in Nutrients
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Journal Article
Open access
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GTGeorgios Tzikos
Georgios Tzikos
DTDESPOINA TSALKATIDOU
DESPOINA TSALKATIDOU
GSGeorge Stavrou
George Stavrou
GTGiannoula Thoma
Giannoula Thoma
ACAngeliki Chorti
Angeliki Chorti
Katerina KotzampassiKaterina Kotzampassi
Katerina Kotzampassi
Investigations that focused on the protective role of probiotics against Surgical Site Infections (SSI) in multiple-trauma (MT) patients are generally few, probably due to the complexity of the concept of trauma. We aimed to assess the efficacy of a four-probiotic regime to reduce the incidence of SSI in MT patients, with a brain injury included. MT patients, being intubated and expected to require mechanical ventilation for >10 days, were randomly allocated into placebo (n = 50) or probiotic treatment (n = 53) comprising Lactobacillus acidophilus LA-5 (1.75 × 109 cfu), Lactiplantibacillus plantarum UBLP-40 (0.5 × 109 cfu), Bifidobacterium animalis subsp. lactis BB-12 (1.75 × 109 cfu), and Saccharomycesboulardii Unique-28 (1.5 × 109 cfu) in sachets. All patients received two sachets of placebo or probiotics twice/day for 15 days and were followed-up for 30 days. The operations were classified as neurosurgical, thoracostomies, laparotomies, orthopedics, and others; then, the SSI and the isolated pathogen were registered. A total of 23 (46.0%) and 13 (24.5%) infectious insults in 89 (50 placebo patients) and 88 (53 probiotics-treated) operations (p = 0.022) were recorded, the majority of them relating to osteosynthesis—17 and 8, respectively. The most commonly identified pathogens were Staphylococcus aureus and Acinetobacter baumannii. Our results support published evidence that the prophylactic administration of probiotics in MT patients exerts a positive effect on the incidence of SSI.

22 November 2023 in Cancers
Verified
Journal Article
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EFElena Fountzilas
Elena Fountzilas
KPKYRIAKI PAPADOPOULOU
KYRIAKI PAPADOPOULOU
TCThomas Chatzikonstantinou
Thomas Chatzikonstantinou
GKGEORGIOS KARAKATSOULIS
GEORGIOS KARAKATSOULIS
PCPANTELIS CONSTANTOULAKIS
PANTELIS CONSTANTOULAKIS
MLMichalis Liontos
Michalis Liontos
Our aim was to evaluate the concordance between the Myriad MyChoice and two alternative homologous recombination deficiency (HRD) assays (AmoyDx HRD Focus NGS Panel and OncoScan™) in patients with epithelial ovarian cancer (EOC). Tissue samples from 50 patients with newly diagnosed EOC and known Myriad MyChoice HRD status were included. DNA aliquots from tumor samples, previously evaluated with Myriad MyChoice and centrally reassessed, were distributed to laboratories to assess their HRD status using the two platforms, after being blinded for the Myriad MyChoice CDx HRD status. The primary endpoint was the concordance between Myriad MyChoice and each alternative assay. Tumor samples were evaluated with an AmoyDx® HRD Focus Panel (n = 50) and with OncoScan™ (n = 43). Both platforms provided results for all tumors. Analysis showed that correlation was high for the Myriad MyChoice GI score and AmoyDx® HRD Focus Panel (r = 0.79) or OncoScan™ (r = 0.87) (continuous variable). The overall percent agreement (OPA) between Myriad MyChoice GI status (categorical variable) and each alternative assay was 83.3% (68.6–93.3%) with AmoyDx and 77.5% (61.5–89.2%) with OncoScan™. The OPA in HRD status between Myriad MyChoice and AmoyDx was 88.6% (75.4–96.2). False-positive rates were 31.6% (6/19) for AmoyDx GI status and 31.9% (7/22) for OncoScan™, while false-negative rates were 0% (0/28, AmoyDx) and 11.1% (2/18, OncoScan™) compared with the Myriad MyChoice GI status. While substantial concordance between Myriad MyChoice and alternative assays was demonstrated, prospective validation of the analytical performance and clinical relevance of these assays is warranted.