Search

Your search keyword '"Alexandros Alexandropoulos"' showing total 8 results
Start Over Author "Alexandros Alexandropoulos"
8 results on '"Alexandros Alexandropoulos"'

1. Circulating miR-16 and miR-21 Levels in Multiple Myeloma: Prognostic Significance of Survival and Response to Lenalidomide Treatment

Author

Annita-Ioanna Gkioka, Maria Tsota, Aspasia Koudouna, Alexandros Gkiokas, Christina-Aggeliki Mitropoulou, Aikaterini Palaiokrassa, Alexandros Alexandropoulos, Mavra Papadatou-Gigante, Vasiliki Bartzi, Thomais-Marina Tryfou, Petros P. Sfikakis, George V. Dedoussis, and Marie-Christine Kyrtsonis

Subjects
multiple myeloma, miR-16, miR-21, prognosis, lenalidomide, serum expression level, Biology (General), QH301-705.5, Chemistry, QD1-999
Abstract

MicroRNAs (miRNAs), particularly miR-16 and miR-21, play a crucial role in multiple myeloma (MM) pathogenesis by regulating gene expression. This study evaluated the prognostic significance of circulating miR-16 and miR-21 expression levels in 48 patients with MM at diagnosis treated with lenalidomide–dexamethasone (LD) compared with 15 healthy individuals (HI). All patients were treated with LD, 13 at first line and 35 at relapse, of whom 21 were tested twice at diagnosis and before LD initiation. The results revealed significantly lower levels of miR-16 and miR-21 in patients than in HIs, both at diagnosis and relapse, with decreased miR-16 levels at diagnosis, indicating improved overall survival (OS) (p value 0.024). Furthermore, miR-16 and miR-21 levels were associated with disease markers, while both correlated with the depth of response and mir-16 with sustained response to LD treatment. Ratios of both miR-16 and miR-21 expression levels (prior to LD treatment/diagnosis) below two predicted a shorter time to response (p = 0.027) and a longer time to next treatment (p = 0.042), respectively. These findings suggested a prognostic value for serum miR-16 and miR-21 levels in MM, as their expression levels correlated with disease variables and treatment outcomes.

Published
2024
Full Text
View/download PDF

2. Serum-Soluble CD163 Levels as a Prognostic Biomarker in Patients with Diffuse Large B-Cell Lymphoma Treated with Chemoimmunotherapy

Author

Aspasia Koudouna, Annita Ioanna Gkioka, Alexandros Gkiokas, Thomai M. Tryfou, Mavra Papadatou, Alexandros Alexandropoulos, Vassiliki Bartzi, Nikolitsa Kafasi, and Marie-Christine Kyrtsonis

Subjects
soluble CD163 (sCD163), tumor-associated macrophages (TAMs), Diffuse Large B-cell Lymphoma (DLBCL), serum samples, prognosis, Biology (General), QH301-705.5, Chemistry, QD1-999
Abstract

The majority of patients with Diffuse Large B-cell Lymphoma (DLBCL) will respond to first-line treatment and be cured. However, the disease is heterogeneous, and biomarkers able to discriminate patients with suboptimal prognosis are needed. M2 CD163-positive tumor-associated macrophages (TAMs) were shown to be implicated in DLBCL disease activity regulation. Serum-soluble CD163 (sCD163) functions as a scavenger receptor for haptoglobin–hemoglobin complexes and is mostly expressed by monocytes and macrophages. Its levels are used to determine macrophage activation. We aimed to determine serum sCD163 in a sample of DLBCL patients and study eventual correlations with parameters of disease activity or survival. Serum sCD163 levels were measured in 40 frozen sera from patients diagnosed with DLBCL and 30 healthy individuals (HIs) using an enzyme-linked immunosorbent assay (ELISA). Statistical analyses were performed using SPSS version 28. The results showed that patients who achieved complete response after standard-of-care immunochemotherapy and were alive and disease-free after 12 months of follow-up but had elevated sCD163 levels (above median) at diagnosis presented a significantly worse overall survival compared to those with initial serum sCD163 levels below the median (p = 0.03). Consequently, serum sCD163 levels in patients with DLBCL may constitute a marker of long-term response to chemoimmunotherapy.

Published
2024
Full Text
View/download PDF

4. A cross-sectional analysis of the prevalence of tooth agenesis and structural dental anomalies in association with cleft type in non-syndromic oral cleft patients

Author

Dimitrios Konstantonis, Alexandros Alexandropoulos, Nikoleta Konstantoni, and Maria Nassika

Subjects
Cleft lip and palate, Dental anomalies, Tooth agenesis, Microdontia, Dentistry, RK1-715
Abstract

Abstract Background The aim of this study was to investigate the prevalence of tooth agenesis, microdontia, and tooth malformation among non-syndromic oral cleft patients and their potential association with cleft type and gender. Methods Intraoral records and radiographs of 154 patients (97 males and 57 females) were examined. The variables assessed were tooth agenesis, microdontia, dental malformations, and cleft types. The statistics included chi-square and Fisher’s exact tests as well as logistic regression to assess any mutual effects of gender and cleft type on the dental variables. Results Tooth agenesis occurred in 50% of the sample and microdontia in 18%. Non-statistically significant odds ratios for the association of gender and cleft type with tooth agenesis were obtained. Tooth agenesis was substantially higher at the unilateral right CL + P and the bilateral CL + P in quadrant 1 and at the unilateral left CL + P and bilateral CL + P in quadrant 2. It was also higher, at the isolated cleft palate (CP) in quadrants 3 and 4. These results were attributed to teeth 22 (31.8%) and 12 (21.6%) in the maxilla and to teeth 35 (6.1%) and 45 (5.4%) in the mandible. In unilateral CL + P patients, the cleft quadrant that presented tooth agenesis was associated with the side of the cleft. Conclusions Interdisciplinary treatment of the oral cleft patients should take into consideration the high prevalence of tooth agenesis and their association with the different cleft types. The most frequently affected teeth by cleft are by far the upper lateral incisors. Results indicate that tooth agenesis appears to be a genetically controlled anomaly related to the orofacial cleft development through various genetic links and not caused by the cleft disruptive process.

Published
2017
Full Text
View/download PDF

6. Chemical and mechanical characteristics of contemporary thermoplastic orthodontic materials

Author

Spiros Zinelis, Alexandros Alexandropoulos, Youssef S. Al Jabbari, and Theodore Eliades

Subjects
chemistry.chemical_classification, Thermoplastic, Materials science, chemistry, Orthodontics, Composite material, Dentistry, Orthodontics & Medicine
Abstract

Aim The aim of the present study was to characterise the chemical and mechanical properties of contemporary thermoplastic orthodontic materials. Materials and methods Four thermoplastic materials were tested: Clear Aligner (Scheu-Dental), ACE and A+ (Dentsply), and Invisalign (Align Technology). Eight appliances were fabricated from each material and a small portion from each was analysed by ATR-FTIR spectroscopy. The appliances were cut and, following metallographic grinding and polishing, were subjected to instrumented indentation testing (IIT) employing a Vickers indenter. Martens Hardness (HM), Indentation Modulus (EIT), Elastic to Total Work Ratio (elastic index (ηIT)) and Indentation Creep (CIT) were determined according to ISO 14577-1. The mean values of the mechanical properties were statistically analysed by one way ANOVA and Tukey Kramer multiple comparison test at a = 0.05. Results ATR-FTIR analysis identified that Invisalign was a polyurethane-based material, whereas the others were based on polyester, polyethylene glycol terephthalate (PETG). Invisalign showed higher hardness and modulus values, a slightly higher brittleness and lesser creep resistance compared with the PETG-based products. Conclusions The materials tested showed significant differences in their chemical structure and mechanical properties and therefore differences in their clinical behaviour are anticipated.

Published
2021

7. A cross-sectional analysis of the prevalence of tooth agenesis and structural dental anomalies in association with cleft type in non-syndromic oral cleft patients

Author

Dimitrios Konstantonis, Nikoleta Konstantoni, Maria Nassika, and Alexandros Alexandropoulos

Subjects
Male, Microdontia, Cross-sectional study, Cleft Lip, Dentistry, Orthodontics, Dental anomalies, 03 medical and health sciences, Quadrant (abdomen), 0302 clinical medicine, Sex Factors, stomatognathic system, Cleft lip and palate, Tooth agenesis, Prevalence, Medicine, Humans, 10. No inequality, Anodontia, Oral cleft, Greece, business.industry, Tooth Abnormalities, Research, 030206 dentistry, Odds ratio, medicine.disease, lcsh:RK1-715, Cleft Palate, stomatognathic diseases, Cross-Sectional Studies, lcsh:Dentistry, 030220 oncology & carcinogenesis, Maxilla, Female, business
Abstract

Background The aim of this study was to investigate the prevalence of tooth agenesis, microdontia, and tooth malformation among non-syndromic oral cleft patients and their potential association with cleft type and gender. Methods Intraoral records and radiographs of 154 patients (97 males and 57 females) were examined. The variables assessed were tooth agenesis, microdontia, dental malformations, and cleft types. The statistics included chi-square and Fisher’s exact tests as well as logistic regression to assess any mutual effects of gender and cleft type on the dental variables. Results Tooth agenesis occurred in 50% of the sample and microdontia in 18%. Non-statistically significant odds ratios for the association of gender and cleft type with tooth agenesis were obtained. Tooth agenesis was substantially higher at the unilateral right CL + P and the bilateral CL + P in quadrant 1 and at the unilateral left CL + P and bilateral CL + P in quadrant 2. It was also higher, at the isolated cleft palate (CP) in quadrants 3 and 4. These results were attributed to teeth 22 (31.8%) and 12 (21.6%) in the maxilla and to teeth 35 (6.1%) and 45 (5.4%) in the mandible. In unilateral CL + P patients, the cleft quadrant that presented tooth agenesis was associated with the side of the cleft. Conclusions Interdisciplinary treatment of the oral cleft patients should take into consideration the high prevalence of tooth agenesis and their association with the different cleft types. The most frequently affected teeth by cleft are by far the upper lateral incisors. Results indicate that tooth agenesis appears to be a genetically controlled anomaly related to the orofacial cleft development through various genetic links and not caused by the cleft disruptive process.

Published
2016

8. Chemical and mechanical characteristics of contemporary thermoplastic orthodontic materials

Author

Alexandros, Alexandropoulos, Youssef S, Al Jabbari, Spiros, Zinelis, and Theodore, Eliades

Subjects
Chemical Phenomena, Polyethylene Terephthalates, Polyesters, Polyurethanes, Dental Polishing, Polyethylene Glycols, Dental Materials, Orthodontic Appliances, Hardness, Elastic Modulus, Materials Testing, Spectroscopy, Fourier Transform Infrared, Humans, Stress, Mechanical, Plastics, Mechanical Phenomena
Abstract

The aim of the present study was to characterise the chemical and mechanical properties of contemporary thermoplastic orthodontic materials.Four thermoplastic materials were tested: Clear Aligner (Scheu-Dental), ACE and A+ (Dentsply), and Invisalign (Align Technology). Eight appliances were fabricated from each material and a small portion from each was analysed by ATR-FTIR spectroscopy. The appliances were cut and, following metallographic grinding and polishing, were subjected to instrumented indentation testing (IIT) employing a Vickers indenter. Martens Hardness (HM), Indentation Modulus (E(IT)), Elastic to Total Work Ratio (elastic index (η(IT))) and Indentation Creep (C(IT)) were determined according to ISO 14577-1. The mean values of the mechanical properties were statistically analysed by one way ANOVA and Tukey Kramer multiple comparison test at a = 0.05.ATR-FTIR analysis identified that Invisalign was a polyurethane-based material, whereas the others were based on polyester, polyethylene glycol terephthalate (PETG). Invisalign showed higher hardness and modulus values, a slightly higher brittleness and lesser creep resistance compared with the PETG-based products.The materials tested showed significant differences in their chemical structure and mechanical properties and therefore differences in their clinical behaviour are anticipated.

Published
2016

Catalog

Books, media, physical & digital resources
See catalog results