11 results on '"Alexandros Zafiropoulos"'
Search Results
2. Evaluation of STANDARDTM M10 SARS-CoV-2 assay as a diagnostic tool for SARS-CoV-2 in nasopharyngeal or oropharyngeal swab samples
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Maria-Eleni Parakatselaki, Georgia Alexi, Alexandros Zafiropoulos, and George Sourvinos
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Infectious Diseases ,Virology - Published
- 2023
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3. Differential integrin expression in pre-implantation embryos developing under in vivo and in vitro conditions
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Mattheos Fraidakis, George Filippidis, Irene Athanassakis, Aliki Anyfantaki, Christiana Kyvelidou, Margarita Tsagkaraki, and Alexandros Zafiropoulos
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0301 basic medicine ,Integrins ,animal structures ,Reproductive Techniques, Assisted ,Embryonic Development ,Biology ,Embryo Culture Techniques ,Mice ,03 medical and health sciences ,Endocrinology ,In vivo ,Animals ,Cell adhesion ,Zygote ,Cell adhesion molecule ,Embryogenesis ,Embryo ,Embryo culture ,Lipid Droplets ,In vitro ,Cell biology ,Blastocyst ,030104 developmental biology ,embryonic structures ,Animal Science and Zoology ,Developmental Biology - Abstract
Implantation failure is a major problem in human assisted reproduction, which persists regardless the optimization of endometrial receptivity and selection of genetically and morphologically healthy embryos. Since embryo-endometrium interaction depends on cell junctional, cell adhesion and cell-substratum adhesion molecules, the present study inquired whether in vitro growing murine embryos display similar to the in vivo growing embryos patterns of adhesion molecules. To this extend aVb3 expression and distribution in zygotes and 2-cell stage embryos were studied. The results demonstrated that only the in vivo growing embryos displayed specifically polarized aVb3 distribution, indicating their potential successful interaction with endometrium. Based on previous studies showing that L-carnitine (L-Cn) could affect embryonic development, it was demonstrated that the addition of L-Cn to the culture medium, could lead the in vitro growing embryos to acquire aVb3 expression and distribution similar to the in vivo growing embryos. Visualization of the effect of L-Cn using third harmonic generation imaging showed decreased lipid droplet levels in 2-cell-stage embryos, observation that correlates with an active energetic state of the growing embryos. Thus, the application of L-Cn to the culture medium could assist pre-implantation-state embryos to acquire aVb3 expression and distribution similar to the in vivo developing conditions.
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- 2018
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4. Sample pooling strategies for SARS-CoV-2 detection
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Ioanna Mourkioti, Angelos Papaspyropoulos, Konstantinos Evangelou, Aikaterini Polyzou, George Sourvinos, Alexandros Zafiropoulos, Vassilis G. Gorgoulis, Nefeli Lagopati, and Panagiota Tsioli
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0301 basic medicine ,Consumables ,Coronavirus disease 2019 (COVID-19) ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,030106 microbiology ,Population ,Pooling ,Sample (statistics) ,Biology ,Article ,Specimen Handling ,03 medical and health sciences ,COVID-19 Testing ,Virology ,Humans ,education ,Human resources ,Pandemics ,education.field_of_study ,Pooling methods ,SARS-CoV-2 ,Diagnostic Tests, Routine ,business.industry ,COVID-19 ,Hierarchical algorithm ,N genes ,030104 developmental biology ,Risk analysis (engineering) ,business ,Array testing - Abstract
Highlights • The COVID-19 pandemic emerges the need of rapid and accurate diagnostic testing. • Testing on pooled samples maximizes the number of tested samples in a short time. • Testing on pooled samples minimizes the time and the consumables needed. • Hybrid methods (“in house” methods and sample pooling) might allow rapid screening. • The prevalence of the virus justifies the use of the pooling protocol., The worldwide COVID-19 pandemic outburst has caused a serious public health issue with increasing needs of accurate and rapid diagnostic and screening testing. This situation requires an optimized management of the chemical reagents, the consumables, and the human resources, in order to respond accurately and effectively, controlling the spread of the disease. Testing on pooled samples maximizes the number of tested samples, by minimizing the time and the lab supplies needed. The general conceptualization of the pooling method is based on mixing samples together in a batch. Individual testing is needed only if a specific pool exhibits a positive result. The development of alternative hybrid methods, based on “in house” protocols, utilizing commercially available consumables, in combination with a reliable pooling method would provide a solution, focusing on the better exploitation of the personnel and the lab supplies, allowing for rapid screening of a population in a reasonably short time.
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- 2021
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5. Peritoneal fluid concentrations of β-chemokines in endometriosis
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Alexandros Zafiropoulos, Ioannis Matalliotakis, Christina Giannakopoulou, Aydin Arici, Eleftheria Hatzidaki, and Kalliopi-Maria Margari
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Infertility ,medicine.medical_specialty ,business.industry ,Peritoneal fluid ,Pelvic pain ,Endometriosis ,Obstetrics and Gynecology ,medicine.disease ,Gastroenterology ,Reproductive Medicine ,Statistical significance ,Internal medicine ,Post-hoc analysis ,Ascitic Fluid ,Humans ,Medicine ,Female ,Analysis of variance ,Chemokine CCL7 ,Stage (cooking) ,medicine.symptom ,business ,Chemokine CCL5 ,Chemokine CCL2 - Abstract
Objective To examine whether the levels of MCP-1, RANTES and MCP-3 in the peritoneal fluid correlate with endometriosis. Study design Patients with endometriosis were compared with controls. Setting: Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA. Subjects: This study involved 95 women of reproductive age who were undergoing laparoscopy for evaluation of infertility or for pelvic pain. They were divided into an endometriosis group (n = 54) and a control group (n = 41). Interventions: Peritoneal fluid samples were obtained and β-chemokines (MCP-1, RANTES and MCP-3) were measured using ELISA. Statistical analysis: Mean and median values were used to present values. Due to the non-normality of chemokines, a log transformation was applied. Differences were examined using independent samples t-test. One-way ANOVA and Tukey HSD multiple comparison post hoc tests were applied. A significance level at 0.05 was set. Results The levels of MCP-1 are higher (p for log values = 0.024) in the control group (mean = 687.6, SD = 467.7 pg/ml) than those of the endometriosis group (mean = 570.4, SD = 633.1 pg/ml). The same is true for the median values of MCP-1 (control median = 568.5, endometriosis median = 384.7 pg/ml). MCP-3 and RANTES do not differ significantly (MCP-3 p = 0.787, RANTES p = 0.153). The levels of MCP-1 in patients with stage II endometriosis are significantly lower in comparison with stage III (p = 0.048) and stage IV (p = 0.033) endometriosis. Conclusions A decrease in the concentrations of MCP-1 in stage I endometriosis has been observed, which is even larger in stage II, in contrast to stage III and stage IV endometriosis, which exhibit concentrations similar to the controls.
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- 2013
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6. Paraoxonase 1 R/Q alleles are associated with differential accumulation of saturated versus 20:5n3 fatty acid in human adipose tissue
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Alexandros Zafiropoulos, Aristidis Tsatsakis, Manolis Linardakis, A Kafatos, George N. Tzanakakis, and Eugène H.J.M. Jansen
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Adult ,Male ,medicine.medical_specialty ,Genotype ,Apolipoprotein B ,Lipoproteins ,Adipose tissue ,QD415-436 ,Biochemistry ,chemistry.chemical_compound ,Endocrinology ,Surveys and Questionnaires ,Internal medicine ,medicine ,Animals ,Humans ,Alleles ,Aged ,chemistry.chemical_classification ,Polymorphism, Genetic ,Greece ,biology ,Triglyceride ,Aryldialkylphosphatase ,dyslipidemia ,Fatty Acids ,Paraoxonase ,Fatty acid ,Cell Biology ,Middle Aged ,medicine.disease ,Lipids ,PON1 ,lipid homeostasis ,Cross-Sectional Studies ,Adipose Tissue ,Eicosapentaenoic Acid ,chemistry ,Saturated fatty acid ,Fatty Acids, Unsaturated ,biology.protein ,lipidomics ,Female ,Metabolic syndrome ,Patient-Oriented and Epidemiological Research - Abstract
Serum paraoxonase 1 (PON1) function has been associated with human cardiovascular disease. The projected mechanism postulates interaction of PON1 with lipoproteins and insulin signaling resulting in alterations in lipid homeostasis. Recently, PON2 was shown to directly regulate triglyceride accumulation in macrophages and PON1 was detected in the interstitial space of adipocytes. The aims of the present study were a) to examine the relationship of the PON1 function with serum parameters related to lipid homeostasis, and b) to examine a possible role of PON1 in the regulation of lipid composition in the human adipose tissue. Two important genetic variations with functional impact on PON1 activity in humans are the Q192R and the L55M. The present study evaluated the impact of the Q192R and the L55M polymorphisms in a cross-section of the population on the island of Crete, as regards to PON1 activity, plasma lipids/lipoproteins, parameters of the metabolic syndrome, and the fatty acid composition of the adipose tissue. We detected a significant association of the polymorphisms with blood pressure, fasting blood glucose, triglycerides, apolipoprotein B, serum iron, and homocysteine. Furthermore, a novel function is suggested for PON1 on the fatty acid composition in the adipose tissue through the positive association of the R allele with saturated fatty acid and of the Q allele with 20:5n3 fatty acid deposition.
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- 2010
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7. Transcriptional activation of H- and N-ras oncogenes in human cervical cancer
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Ioannis N. Mammas, Demetrios A. Spandidos, Alexandros Zafiropoulos, Eugenios Koumantakis, and Stavros Sifakis
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Adult ,Transcriptional Activation ,Uterine Cervical Neoplasms ,Adenocarcinoma ,Cervical intraepithelial neoplasia ,medicine ,Humans ,Point Mutation ,RNA, Messenger ,Papillomaviridae ,Aged ,Aged, 80 and over ,Cervical cancer ,biology ,Point mutation ,Papillomavirus Infections ,HPV infection ,Obstetrics and Gynecology ,Cancer ,Middle Aged ,Uterine Cervical Dysplasia ,medicine.disease ,biology.organism_classification ,Molecular biology ,Gene Expression Regulation, Neoplastic ,Tumor Virus Infections ,Genes, ras ,Real-time polymerase chain reaction ,Oncology ,DNA, Viral ,Carcinoma, Squamous Cell ,Female - Abstract
Objective . Overexpression of p21 protein has been detected in human cervical cancer. However, to date, there are no data on the differential activation of the three ras genes at the transcriptional level in cervical lesions. The purpose of this study was to evaluate the quantitative and qualitative changes of expression of the ras family genes in the development of human cervical cancer. Methods . The expression of ras mRNA levels in 35 human cervical specimens [11 normal cervix, 15 cervical intraepithelial neoplasia (CIN), 9 cervical cancer] was examined using the RT-PCR technique. In addition, we studied the incidence of point mutations in codon 12 of each ras gene using RFLP analysis and human papilloma virus (HPV) status. Results . The transcript levels for H- ras and N- ras were significantly higher in cancer cases compared to normal cervical tissues ( P = 0.0002 and P = 0.001, respectively) and CIN lesions ( P P = 0.002, respectively). The transcript levels for K- ras were similar in normal cervical tissue, CIN and cervical cancer. A strong positive correlation was found between H- and N- ras expression ( P = 0.001) and no correlation between H- and K- or N- and K- ras expression. Point mutations were detected only in three samples, located in codon 12 of K- ras gene. No relationship was found between expression levels of each ras gene and the presence of HPV. Conclusion . Our findings indicate the expression pattern of the three ras genes in cervical tissue and the involvement of H- and N- ras up-regulation in the pathogenesis of cervical cancer independent of HPV infection.
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- 2004
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8. Human herpes viruses in non-melanoma skin cancers
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K Billiri, Demetrios A. Spandidos, Alexandros Zafiropoulos, and E. Tsentelierou
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Adult ,Cancer Research ,Pathology ,medicine.medical_specialty ,Skin Neoplasms ,Herpesvirus 2, Human ,Cytomegalovirus ,Herpesvirus 1, Human ,medicine.disease_cause ,Herpesviridae ,Virus ,Betaherpesvirinae ,medicine ,Humans ,Simplexvirus ,Aged ,biology ,Herpes Simplex ,Middle Aged ,medicine.disease ,biology.organism_classification ,Epstein–Barr virus ,Virology ,Herpes simplex virus ,Oncology ,DNA, Viral ,Female ,Viral disease ,Skin cancer - Abstract
We examined the possible involvement of human herpes viruses in sporadic non-melanoma skin cancer of Greek patients. Polymerase chain reaction (PCR) based detection assays were utilized for the detection of viral cytomegalovirus (CMV), herpes simplex virus (HSV) and Epstein-Barr virus (EBV) genomes in 24 squamous cell carcinomas (SCC), five Bowen's disease, 72 basal cell carcinomas (BCC) specimens and eight premalignant lesions. Forty-two of 109 (38.5%) skin lesions were found positive for CMV DNA. The highest incidence was 6/8 (75%) observed in specimens with premalignant lesions. The incidence was 37.5% (27/72) in BCC, 33% (8/24) in SCC and 20% (1/5) in extragenital Bowen's disease. All samples were negative for HSV-1/2 and EBV DNA as assessed by our PCR based assay. The CMV infection showed no statistically significant correlation with the histological type, age, site of lesion or sex. Our results give a strong indication of the possible involvement of CMV in non-melanoma skin cancer development.
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- 2003
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9. Induction of antigen-specific isotype switching by in vitro immunization of human naive B lymphocytes
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Carl A.K. Borrebaeck, Alexandros Zafiropoulos, Elias Krambovitis, and Eva Andersson
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Molecular Sequence Data ,Naive B cell ,Immunology ,chemical and pharmacologic phenomena ,Biology ,Lymphocyte Activation ,Epitope ,Antigen ,Antigen specific ,Tetanus Toxoid ,medicine ,Humans ,Immunology and Allergy ,Amino Acid Sequence ,Antigens ,CD40 Antigens ,B-Lymphocytes ,Toxoid ,T helper cell ,biochemical phenomena, metabolism, and nutrition ,Immunoglobulin Class Switching ,Isotype ,Virology ,In vitro ,medicine.anatomical_structure ,Immunization ,Immunoglobulin class switching ,biology.protein ,bacteria ,Antibody - Abstract
The use of in vitro immunization technology for the generation of human antigen-specific antibodies has essentially resulted in low affinity IgM antibodies, resembling an in vivo primary immune response. We now describe a detailed reproducible protocol for a two-step in vitro immunization, which yields isotype switched, antigen-specific human antibodies. The immunizing antigen was a 30aa synthetic peptide, containing both a B (15aa V3 peptide of the HIV-1) and a T helper cell epitope (15aa peptide from tetanus toxin). The immunization protocol includes: (i) a selection procedure of donors with a memory T cell response against tetanus toxoid; (ii) immunization of mature naive peripheral B lymphocytes in two distinct phases, involving a primary and a secondary step. None of the donors which were examined after primary immunization showed at any time an IgG anti-V3 specific antibody response, while all the donors showed an IgM response. After the secondary immunization step, anti-V3 antibodies of both IgM and IgG isotypes were detected. The switch frequency event was high among the tested donors (5/8).
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- 1997
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10. Associations between PON1 and CYP1A1 genetic polymorphisms and clinical findings of a Greek population exposed to pesticides
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Alexandros Zafiropoulos, Aristidis Tsatsakis, Charilaos Koutis, Athanasios Alegakis, Jyrki Liesivuori, and George N. Tzanakakis
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Genetics ,Environmental health ,General Medicine ,Pesticide ,Biology ,Greek population ,Toxicology ,PON1 - Published
- 2009
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11. Lipopeptide conjugate-coated liposomes enhance the antigen-specific proliferative response in human peripheral blood lymphocytes
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Alexandros Zafiropoulos, Elias Krambovitis, Carl A.K. Borrebaeck, and Eva Andersson
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Liposome ,chemistry.chemical_compound ,Chemistry ,Antigen specific ,Immunology ,Immunology and Allergy ,Lipopeptide ,Peripheral blood mononuclear cell ,Molecular biology ,Peripheral blood ,Proliferative response ,Conjugate - Published
- 1997
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