Papers by Christos Yapijakis
Proceedings of the XXIII World Congress of Philosophy, 2018
Epicurus observed nature with the aim to achieve serenity and a blissful life. This presentation ... more Epicurus observed nature with the aim to achieve serenity and a blissful life. This presentation discusses current knowledge regarding the human brain in comparison with Epicurus' understanding of human nature. The human brain actually consists of three interconnected brains that arose during evolution: the "reptilian brain" (instincts), the "mammalian brain" (emotions) and "the primate brain" (cognitive functions). The philosopher emphasized the fact that the basic needs of humans lay in instincts, he determined the purpose of human life on emotional grounds, and he considered prudence as the supreme agent of selection of physical needs and of satisfaction and preservation of emotional balance through virtue and friendship.
Taylor & Francis eBooks, Feb 16, 2010
... Committee. ΠΑΤΑΡΓΙΑΣ ΘΕΟΧΑΡΗΣ ΛΟΥΚΟΠΟΥΛΟΣ ΔΗΜΗΤΡΗΣ ΑΛΕΠΟΡΟΥ ΒΑΣΙΛΙΚΗ ΣΕΚΕΡ ΗΣ ΚΩΝΣΤΑΝΤΙΝΟΣ ΜΑ... more ... Committee. ΠΑΤΑΡΓΙΑΣ ΘΕΟΧΑΡΗΣ ΛΟΥΚΟΠΟΥΛΟΣ ΔΗΜΗΤΡΗΣ ΑΛΕΠΟΡΟΥ ΒΑΣΙΛΙΚΗ ΣΕΚΕΡ ΗΣ ΚΩΝΣΤΑΝΤΙΝΟΣ ΜΑΡΓΑΡΙΤΗΣ ΛΟΥΚΑΣ ΤΥΠΑΣ ΜΙΛΤΙΑΔΗΣ ΒΑΣΙΛΟΠΟΥΛΟΣ Δ ΗΜΗΤΡΙΟΣ,. Discipline. Natural Sciences Biological Sciences. ...
Advances in Experimental Medicine and Biology, 2021
MicroRNAs (miRNAs) are small noncoding regulatory RNA molecules that play a significant role in t... more MicroRNAs (miRNAs) are small noncoding regulatory RNA molecules that play a significant role in targeted downregulation of gene expression by RNA silencing and posttranscriptional regulation. Mounting evidence of recent studies indicates that there is dysregulation of expression level of a wide range of miRNAs in a variety of cardiovascular diseases related to thrombosis including venous thromboembolism, coronary artery disease, stroke, and myocardial infarction. In this review, the current knowledge on the role of miRNAs in thrombosis is discussed. Future research may further unravel the involvement of miRNAs in the pathogenesis of thrombosis as well as possibly clarify the clinical usefulness of miRNAs as biomarkers and potential therapeutic targets.
Taylor & Francis eBooks, Feb 16, 2010
Conatus - Journal of Philosophy, Dec 31, 2022
All human needs are compromised by everyday stressful conditions, which may be objectively devast... more All human needs are compromised by everyday stressful conditions, which may be objectively devastating or subjectively augmented due to idiosyncratic way of thinking. Unmanaged acute stress can affect emotions, thinking and behavior and chronic stress can result in several severe health problems. Philosophy may provide a frame of thinking that may help in managing everyday stress. There are personal dimensions in the philosophical management of stress based on examples of Aristotle's eudaimonia consisted of morality and pleasure, Plato's transcendence aiming to join with the supreme good, Pyrrho's serenity through suspension of judgement and the Stoics' rational attachment to virtue. Furthermore, there are social dimensions of philosophical management of stress, since there is abundant scientific evidence that stress affects moral decision-making and therefore an ethical theory of life may not be sufficient in stressful conditions. In this context, such social aspects include the relationship of eudaimonia with community life, the artistic practice and the virtual eroticism in the contemporary world of digital media as a stress relief from physical confrontation with other persons in real life, the empathy and care as a crucial quality for stress relief and social change, as well as the Epicurean approach of stress management that may have both personal and social utility. Intervention programs of stress management combining many lifestyle techniques have been shown to enhance resilience and decrease stress for a period of time, based on systematic behavioral change. Two successful novel empirical pilot studies of pure philosophical management of stress based on cognitive psychotherapy and modification of mentality have been presented, both of them realized in the COVID-19 pandemic period: a three-month positive psychology intervention combined with Epicurean and Stoic concepts was provided to adolescent students and a month-long philosophical management of stress program based on Science and Epicurean Philosophy was offered to public sector professionals.
Journal of Molecular Biology, Oct 1, 1989
Temperature-sensitive mutants have been isolated following hydroxylamine mutagenesis of a plasmid... more Temperature-sensitive mutants have been isolated following hydroxylamine mutagenesis of a plasmid containing Escherichia coli rRNA genes carrying selectable markers for spectinomycin resistance (U1192 in 16 S rRNA) and erythromycin resistance (G2058 in 23 S rRNA). These antibiotic resistance alleles, originally identified by Morgan and co-workers, enable us to follow expression of cloned rRNA genes in vivo. Recessive mutations causing the loss of expression of the cloned 16 S rRNA gene were identified by the loss of the ability of cells to survive on media containing spectinomycin. The mutations were localized by in vitro restriction fragment replacement followed by in vivo marker rescue and were identified by DNA sequence analysis. We report here seven single-base alterations in 16 S rRNA (A146, U153, A350, A359, A538, A1292 and U1293), five of which produce temperature-sensitive spectinomycin resistance and two that produce unconditional loss of resistance. In each case, loss of ribosomal function can be accounted for by disruption of base-pairing in the secondary structure of 16 S rRNA. For the temperature-sensitive mutants, there is a lag period of about two generations between a shift to the restrictive temperature and cessation of growth, implying that the structural defects cause impairment of ribosome assembly.
Andrologia, Jun 11, 2014
Genes located on Y chromosome and expressed in testis are likely to be involved in spermatogenesi... more Genes located on Y chromosome and expressed in testis are likely to be involved in spermatogenesis. TTTY2 is a Y-linked multicopy gene family of unknown function that includes TTTY2L2A and TTTY2L12A at Yq11 and Yp11 loci respectively. Using PCR amplification, we screened for TTTY2L2Aand TTTY2L12A-associated deletions, in 94 Greek men with fertility problems. Patients were divided into three groups as following: group A (n = 28) included men with idiopathic moderate oligozoospermia, group B (n = 34) with idiopathic severe oligozoospermia and azoospermia, and group C (n = 32) with oligo-and azoospermia of various known etiologies. No deletions were detected in group C patients and 50 fertile controls. However, two patients from group A had deletions in TTTY2L2A (7.1%) and six in TTTY2L12A (21.4%), whereas from group B, four patients had deletions in TTTY2L2A (11.8%) and 10 in TTTY2L12A (29.4%). In addition, five patients from both groups A and B (8%) appeared to have deletions in both studied TTTY2 genes, although these are located very far apart. These results indicate that the TTTY2 gene family may play a significant role in spermatogenesis and suggest a possible mechanism of nonhomologous recombinational events that may cause genomic instability and ultimately lead to male infertility.
Journal of Musculoskeletal & Neuronal Interactions, Apr 1, 2007
ErbB2 and erbB3 transmembrane receptors, known to be associated with neuronal and skeletal muscle... more ErbB2 and erbB3 transmembrane receptors, known to be associated with neuronal and skeletal muscle developmental function, seem to play an important role in human oral oncogenesis. This study was designed to determine gradual erbB2 and erbB3 expression in an experimental animal system of induced oral carcinogenesis in Syrian golden hamsters. Thirty-seven animals were divided into one control group (N=7) and three experimental groups (N=10 each one), which were treated with carcinogen 9,10-dimethyl-1,2-benzanthracene and sacrificed at 10, 14 and 19 weeks after treatment. The histological status of observed lesions in the three experimental groups corresponded well with tumour advancement (from oral mucosal dysplasia to moderately differentiated squamous cell carcinoma). Tissue sections ranging from normal mucosa to squamous cell carcinoma were studied using monoclonal antibodies against erbB2 and erbB3 proteins. Cytoplasmic erbB2 expression was gradually increased in pre-cancerous stages, remained stable in initial tumour stages and substantially decreased in moderately-differentiated carcinomas, suggesting that it may be useful as an early prognostic factor. On the contrary, erbB3 was not expressed at all either in normal or tumour tissue.
Genes, Aug 2, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Genes, Jun 10, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Archives of Dermatological Research, Aug 8, 2020
Cytokines involved in inflammatory and immune response have been associated with risk for develop... more Cytokines involved in inflammatory and immune response have been associated with risk for development of basal cell carcinoma (BCC). In this study, three functional DNA polymorphisms affecting gene expression were investigated in 54 BCC patients and 111 healthy controls: interleukin-1b (IL-1b) +3953C/T, interleukin-10 (IL-10) − 1082G/A and angiotensinconverting enzyme (ACE) insertion/deletion (I/D) polymorphisms. Significant increase of the variant alleles was observed in IL-10 − 1082G (P = 0.019) and in ACE D (P = 0.003) in BCC patients in comparison to controls. Multivariate logistic regression models evaluated the contribution of homozygous and heterozygous variant polymorphisms to the risk for BCC development. The studied polymorphisms influencing the expression of IL-10 and ACE genes were recognized as potential predictive factors for BCC. These findings suggest a possible molecular mechanism leading to BCC development that is likely to involve the activation of angiotensin receptors in combination with increased plasma levels of IL-10 in patients.
PubMed, Aug 1, 2009
Background: Cervical cancer is the leading cause of mortality among women worldwide, despite exis... more Background: Cervical cancer is the leading cause of mortality among women worldwide, despite existing prevention programs. In light of the recent development of anti-HPV vaccines, the aim of this study was to evaluate concurrently the efficacy of four methods for risk assessment (cytology, colposcopy, HPV molecular typing and detection of biomarkers in cervical biopsies) in an attempt to define the most efficient combination. Patients and methods: The studied group included 62 women with abnormal Pap tests and cervical lesions ranging from cervicitis and condylomas to intraepithelial neoplasias and invasive cancer. All women underwent full colposcopy assessment and colposcopically-taken biopsies were selected for histological examination, immunohistochemical identification of p16, p53, Bcl-2 biomarkers, as well as molecular detection and typing of HPV genomes. Results: Cytology and colposcopy showed very high sensitivity in detecting CIN and cancer (91.7% and 94.4%, respectively), but low specificity (34.6% and 50%, respectively). The detection of the 3 biomarkers reached an impressive sensitivity (83.3%) and a moderate specificity (65.4%). HPV detection and typing achieved 77.8% sensitivity, and the highest specificity of 80.8% in detecting CIN and cancer cases. HPV DNA testing had the highest positive prognostic value (84.9%; confidence interval, CI: 67.4%- 94.3%) and cytology the lowest (66.0%; CI: 51.2%- 78.4%). Coupled HPV typing and colposcopy proved to be the most efficient combination, increasing sensitivity to 97.2% and negative prognostic value to 92.3%. The estimation of cervical neoplasia or cancer in women with high-risk HPV types increased approximately 15-fold (odds ratio, OR: 14.70; CI: 4.30-50.09, p<0.001), ~23-fold in the case of combined positive biomarkers (OR: 23.18; CI: 4.97- 104.23, p<0.001), and 35-fold in case of colposcopically detected cervical neoplasia (OR: 35.00; CI: 5.16- 225.07, p<0.001). Conclusion: The most efficient combination among all tested methodologies was found to be HPV typing with colposcopy.
PubMed, Aug 6, 2005
Background: Methylenetetrahydrofolate reductase is associated with pathogenesis of both thrombosi... more Background: Methylenetetrahydrofolate reductase is associated with pathogenesis of both thrombosis and oral cancer. Therefore, a search for a similar association of other thrombosis-related factors with oral cancer is justified. Patients and methods: In order to investigate whether the coagulation factor V Leiden and prothrombin G20210A mutations increase the risk of oral cancer, we searched for these mutant alleles by RFLP analysis in DNA samples of 102 patients with oral cancer and 120 healthy controls. Results: Neither the Leiden nor the G20210A alleles were found in statistically different frequencies in the two groups. In addition, no statistical difference was observed in parameters such as sex, age and positive family history for cancer. Nevertheless, a significant difference was observed for Leiden in patients with a positive history for thrombophilia (p < 0.001). Conclusion: There seems to be no association of prothrombin, and possibly a minor contribution of factor V, in oncogenesis in the oral region.
Journal of Cancer Research and Clinical Oncology, Dec 20, 2005
Two polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene, C677T and A1298C, were... more Two polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene, C677T and A1298C, were hypothesized to decrease the risk of acute lymphoblastic leukemia (ALL). Studies examining the associations between these two polymorphisms and ALL susceptibility drew inconsistent results. To obtain a reliable conclusion in a Chinese population, we carried out a meta-analysis. In total, 11 studies on C677T polymorphism (1597 cases and 2295 controls) and 10 studies on A1298C polymorphism (1553 cases and 2224 controls) were included in the meta-analysis. We found a significant association between the 677T variant and reduced ALL risk in Chinese children (Dominant model: odds ratio [OR FE ] = 0.73, 95% confidence interval [CI]: 0.63-0.86, p < 0.01). Heterogeneity between the studies in the children subgroup was weak and vanished after excluding one study deviating from HWE in the control group (p > 0.1). In the adult subgroup, there was no significant association between the C677T variant and ALL risk (Dominant model: OR RE = 0.88, 95% CI: 0.45-1.72, p = 0.72). Significant heterogeneity was found in the adult subgroup in all the genetic model tests (p < 0.1). The A1298C polymorphism had an effect on ALL risk neither in adults (Dominant model: OR FE = 0.95, 95% CI: 0.71-1.27, p = 0.72) nor in children (Dominant model: OR FE = 1.02, 95% CI: 0.87-1.21, p = 0.77). No significant heterogeneity between studies on A1298C polymorphism was found in the meta-analysis (p > 0.1). The results showed that there was a protective effect of the MTHFR C677T variant on ALL risk in Chinese children.
Journal of Neurology, 1996
ABSTRACT
Archives of Oral Biology, Jun 1, 2023
Springer eBooks, 2021
INTRODUCTION Frontometaphyseal dysplasia 1 (FMD1) is a rare X-linked craniofacial syndrome belong... more INTRODUCTION Frontometaphyseal dysplasia 1 (FMD1) is a rare X-linked craniofacial syndrome belonging in the otopalatodigital spectrum of disorders. Here we present a case with severe FMD1 that was caused by a mutation in the FLNA gene located on Xq28. METHODS A diagnosis for FMD1 was clinically set for a 22-year-old male who presented with cranial hyperostosis with marked supraorbital ridge, hypertelorism, progressive mixed hearing loss, partial anodontia, scoliosis, generalized skeletal dysplasia, and muscle atrophy. The patient's two older brothers had also severe FMD1 manifestations with generalized skeletal dysplasia, cranial hyperostosis, progressive hearing loss, and scoliosis, while their mother and maternal grandmother had some less prominent FMD1 signs. Total DNA was extracted from blood samples of the patient, his brothers, and his parents. RESULTS DNA sequencing of all 48 exons of the FLNA gene revealed a single-point mutation (3476A>C) in exon 22. The missense mutation changes an Asp codon into an Ala codon in amino acid position 1159. The patient's two brothers had the same mutation, while their mother was a heterozygous carrier having both the mutant allele and the normal allele. CONCLUSION The clinical diagnosis for FMD1 was confirmed by genetic analysis. It is evident that the FLNA gene product filamin A plays a critical developmental role in morphogenesis of several tissues being a cytoskeleton component, since mutations in its gene cause multiple manifestations and diverse disorders of the otopalatodigital spectrum.
Conatus - Journal of Philosophy, Dec 31, 2022
Epicurus used an empirical and sensualistic approach to knowledge, creating a consistent, natural... more Epicurus used an empirical and sensualistic approach to knowledge, creating a consistent, naturalistic, pragmatic and consequentialistic philosophy. The scientific observations of the last centuries have confirmed the basic principles of Epicurean physics, as well the psychotherapeutic approach of Epicurean ethics, which fits human nature. We know from the work "On Frank Criticism" of Epicurean philosopher Philodemus of Gadara, that the teaching methodology of Epicureans included psychoeducational counseling through therapeutic criticism based on friendly freedom of speech and aiming at τῆς ψυχῆς θεραπείαν (psychotherapy) and at knowledge of maintaining mental health and well-being. The Epicureans called εὐστάθεια (eustatheia, "stability") the psychosomatic balance (τὸ τῆς σαρκὸς καὶ ψυχῆς εὐσταθὲς κατάστημα), which today we call homeostasis (ὁμοιόστασις), and considered it the basis of true happiness. They recognized empirically the stress that disturbed psychosomatic homeostasis as an agitation of the psyche or a painful feeling of the body and used a number of mental and affective techniques (including the tetrapharmakos) to manage stress at its onset, so that it does not evolve into the particularly troublesome conditions of anxiety and/or depression, which may become chronic psychosomatic disorders with significant social consequences. The article discusses the relation of the main ethical teachings of Epicurus with the biological basis of human brain functions and with the management of stress by cognitive and behavioral psychotherapy.
Experimental and Therapeutic Medicine, Jul 19, 2022
In recent years, research on exosomes and their content has been intensive, which has revealed th... more In recent years, research on exosomes and their content has been intensive, which has revealed their important role in cell-to-cell communication, and has implicated exosomal biomolecules in a broad spectrum of physiological processes, as well as in the pathogenesis of various diseases. Pregnancy and its normal progression rely highly on the efficient communication between the mother and the fetus, mainly mediated by the placenta. Recent studies have established the placenta as an important source of circulating exosomes and have demonstrated that exosome release into the maternal circulation gradually increases during pregnancy, starting from six weeks of gestation. This orchestrates maternal-fetal crosstalk, including maternal immune tolerance and pregnancy-associated metabolic adaptations. Furthermore, an increased number of secreted exosomes, along with altered patterns of exosomal non-coding RNAs (ncRNAs), especially microRNAs and long non-coding RNAs (lncRNAs), have been observed in a number of pregnancy complications, such as gestational diabetes mellitus and preeclampsia. The early detection of exosomes and specific exosomal ncRNAs in various biological fluids during pregnancy highlights them as promising candidate biomarkers for the diagnosis, prognosis and treatment of numerous pregnancy disorders in adolescents and adults. The present review aimed to provide insight into the current knowledge regarding the potential, only partially elucidated, role of exosomes and exosomal cargo in the regulation and progression of normal pregnancy, as well as their potential dysregulation and contribution to pathological pregnancy situations.
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Papers by Christos Yapijakis