EVIDENCE FOR INDUCED SEISMICITY FOLLOWING THE 2001 SKYROS MAINSHOCK

Estimation of the seismicity rate changes caused by a major earthquake is based upon the assumption that the earthquake occurrence can be described by stochastic processes. Three stochastic models are applied to the data, i.e. the homogeneous Poisson model, the non-homogeneous Poisson model with two different rate functions, and the Autoregressive model AR(2). The two latter models seem to be adequate to properly simulate the earthquake production in a given area. The identification of the model which best fits the data, enables the estimations of the seismicity rate changes and the numbers of the earthquakes following a specific main shock

COVID-19 and post-traumatic stress disorder: The perfect 'storm' for mental health (Review).

Since its outbreak, in December, 2019, in the Chinese city of Wuhan, coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved into an ongoing global pandemic. Due to the novel antigenic properties of this virus, the world population could not develop immunity effectively and this led to the subsequent spread of COVID-19. This caused an unprecedented emergency situation with significant negative effects on health and well-being both on an individual and societal level. Apart from health, economic and social consequences, the impact of this pandemic on mental health is increasingly being reported in the scientific literature. The present review aimed to provide a comprehensive discussion of the possible neurological and neuropsychiatric manifestations of SARS-CoV-2, together with the related underlying molecular pathways. In addition, the present review focused on populations which are at a higher risk of developing psychiatric disturbances due to the COVID-19 pandemic and discussed possible routes of clinical management and therapeutics to minimize the burden associated with psychiatric disorders. Moreover, research findings exploring the prevalence of COVID-19-related post-traumatic stress disorder (PTSD) symptoms across vulnerable groups, including children, adolescents and COVID-19 survivors are presented, with particular emphasis on those with severe disease who required hospitalization and/or intensive care unit admission. Based on the available literature, the identification of potential determinants associated with PTSD across the different populations is underlined. Lessons learnt from the pandemics across the globe together with the ongoing research on COVID-19 and its impact on mental health, highlight the utmost importance for evidence-based, proactive and targeted interventions in high-risk groups aiming to mitigate the risks and manage vulnerabilities

Iron chelation with deferasirox for the treatment of secondary hemosiderosis in pediatric oncology patients: A single-center experience

Pediatric oncology patients are often iron overloaded, due to the multiple blood transfusions necessary during the course of chemotherapy. Our aim is to report the efficacy and safety of deferasirox, an oral iron chelator, in this patient group. Deferasirox was administered to 13 children with malignancies in remission and iron overload. Ferritin, blood urea nitrogen, creatinine, transaminases, and bilirubin were recorded at 4-to 8-week intervals, and hepatic and cardiac iron overload were assessed with magnetic resonance imaging before initiation of treatment. Deferasirox was administered for an average of 6 months (SD=4.5; range, 0.3 to 18.2). Two children presented with skin rash, 1 with gastrointestinal disturbances, and 1 with fully reversible acute renal failure. The mean monthly rate of change in ferritin levels was-10.8 μg/L before initiation of treatment (95% confidence interval [CI],-19.8 to-1.8; P=0.02) and-93.6 μg/L during deferasirox treatment (95% CI,-118.1 to-69.1; P<0.001). The difference in the monthly rate of change in ferritin levels before and after treatment initiation was-82.8 μg/L (95% CI,-111.6 to-53.9; P<0.001). Deferasirox was effective in reducing the iron burden. The adverse effects were easily monitored and managed. Further studies are warranted to investigate the effect of deferasirox on mortality and morbidity in this population. © 2013 Lippincott Williams & Wilkins

Roles of DNA repair enzyme OGG1 in innate immunity and its significance for lung cancer

Cytokines are pivotal mediators of the immune response, and their coordinated expression protects host tissue from excessive damage and oxidant stress. Nevertheless, the development of lung pathology, including asthma, chronic obstructive pulmonary disease, and ozone-induced lung injury, is associated with oxidant stress; as evidence, there is a significant increase in levels of the modified guanine base 7,8-dihydro-8-oxoguanine (8-oxoG) in the genome. 8-OxoG is primarily recognized by 8-oxoguanine glycosylase 1 (OGG1), which catalyzes the first step in the DNA base excision repair pathway. However, oxidant stress in the cell transiently halts enzymatic activity of substrate-bound OGG1. The stalled OGG1 facilitates DNA binding of transactivators, including NF-κB, to their cognate sites to enable expression of cytokines and chemokines, with ensuing recruitments of inflammatory cells. Hence, defective OGG1 will modulate the coordination between innate and adaptive immunity through excessive oxidant stress and cytokine dysregulation. Both oxidant stress and cytokine dysregulation constitute key elements of oncogenesis by KRAS, which is mechanistically coupled to OGG1. Thus, analysis of the mechanism by which OGG1 modulates gene expression helps discern between beneficial and detrimental effects of oxidant stress, exposes a missing functional link as a marker, and yields a novel target for lung cancer. © 2018 Elsevier Inc

Gene expression and resistance to glucocorticoid-induced apoptosis in acute lymphoblastic leukemia: A brief review and update

Background: Resistance to glucocorticoid (GC)-induced apoptosis in Acute Lympho-blastic Leukemia (ALL), is considered one of the major prognostic factors for the disease. Predniso-lone is a corticosteroid and one of the most important agents in the treatment of acute lymphoblastic leukemia. The mechanics of GC resistance are largely unknown and intense ongoing research focus-es on this topic. Aim: The aim of the present study is to review some aspects of GC resistance in ALL, and in partic-ular of Prednisolone, with emphasis on previous and present knowledge on gene expression and signaling pathways playing a role in the phenomenon. Methods: An electronic literature search was conducted by the authors from 1994 to June 2019. Original articles and systematic reviews selected, and the titles and abstracts of papers screened to determine whether they met the eligibility criteria, and full texts of the selected articles were re-trieved. Results: Identification of gene targets responsible for glucocorticoid resistance may allow discovery of drugs, which in combination with glucocorticoids may increase the effectiveness of anti-leukemia therapies. The inherent plasticity of clinically evolving cancer justifies approaches to characterize and prevent undesirable activation of early oncogenic pathways. Conclusion: Study of the pattern of intracellular signal pathway activation by anticancer drugs can lead to development of efficient treatment strategies by reducing detrimental secondary effects. © 2020 Bentham Science Publishers

Implication of IRF4 Aberrant Gene Expression in the Acute Leukemias of Childhood

The most frequent targets of genetic alterations in human leukemias are transcription factor genes with essential functions in normal blood cell development. The Interferon Regulatory Factor 4 (IRF4) gene encodes a transcription factor important for key developmental stages of hematopoiesis, with known oncogenic implications in multiple myeloma, adult leukemias and lymphomas. Very few studies have reported an association of IRF4 with childhood malignancy, whereas high transcript levels have been observed in the more mature immunophenotype of ALL. Our aim was to investigate the expression levels of IRF4 in the diagnostic samples of pediatric leukemias and compare them to those of healthy controls, in order to determine aberrant gene expression and whether it extends to leukemic subtypes other than the relatively mature ALL subpopulation. Quantitative real-time RT-PCR methodology was used to investigate IRF4 expression in 58 children with acute leukemias, 4 leukemic cell lines and 20 healthy children. We show that aberrant IRF4 gene expression is implicated in a variety of leukemic subtypes; higher transcript levels appear in the more immature B-common ALL subtype and in T-cell than in B-cell leukemias, with the highest expression levels appearing in the AML group. Interestingly, we show that childhood leukemia, irrespective of subtype or cell maturation stage, is characterised by a minimum of approximately twice the amount of IRF4 gene expression encountered in healthy children. A statistically significant correlation also appeared to exist between high IRF4 expression and relapse. Our results show that ectopic expression of IRF4 follows the reverse expression pattern of what is encountered in normal B-cell development and that there might be a dose-dependency of childhood leukemia for aberrantly expressed IRF4, a characteristic that could be explored therapeutically. It is also suggested that high IRF4 expression might be used as an additional prognostic marker of relapse at diagnosis. © 2013 Adamaki et al

Homeobox gene involvement in normal hematopoiesis and in the pathogenesis of childhood Leukemias

Homeobox (HOX) genes are a superfamily of highly conserved genes with essential functions in many aspects of mammalian development. Their expression is tightly regulated throughout the duration of definitive hematopoiesis, so the pathogenetic mechanism that leads to leukemia suggests that malignant transformation is directly intertwined with the deregulation of HOX gene expression. Even though HOX gene involvement has been reviewed extensively in adult leukemias, childhood leukemias have received much less attention and mainly in the context of leukemias harboring MLL (mixed-lineage leukemia) gene translocations. In recent years, scientific evidence has highlighted HOX gene involvement in the development of other subtypes of childhood leukemias and added HOX gene family members that were previously unrelated to the pathogenesis of childhood leukemia. This has significant implications when considering both the risk stratification of pediatric patients and potential targets for successful therapy. Through the identification of HOX target genes, their resulting interactions, and the cognate signaling pathways, we hope to gain a better understanding of the molecular mechanism(s) underlying the ectopic activation of these genes in childhood leukemias and subsequently to reveal new molecular targets for successful therapy in cases of poor prognosis or resistant disease. © 2017 by Begell House, Inc

Aberrant AML1 gene expression in the diagnosis of childhood leukemias not characterized by AML1-involved cytogenetic abnormalities

The AML1 (acute myeloid leukemia 1) gene, a necessary prerequisite of embryonic hematopoiesis and a critical regulator of normal hematopoietic development, is one of the most frequently mutated genes in human leukemia, involving over 50 chromosome translocations and over 20 partner genes. In the few existing studies investigating AML1 gene expression in childhood leukemias, aberrant upregulation seems to specifically associate with AML1 translocations and amplifications. The aim of this study was to determine whether overexpression also extends to other leukemic subtypes than the ones karyotypically involving AML1. We use quantitative real-time polymerase chain reaction methodology to investigate gene expression in 100 children with acute leukemias and compare them to those of healthy controls. We show that in childhood acute lymphoblastic leukemia, AML1 gene overexpression is associated with a variety of leukemic subtypes, both immunophenotypically and cytogenetically. Statistically significantly higher transcripts of the gene were detected in the acute lymphoblastic leukemia group as compared to the acute myeloid leukemia group, where AML1 overexpression appeared to associate with cytogenetic abnormalities additional to those that engage the AML1 gene, or that are reported as showing a “normal” karyotype. Collectively, our study shows that AML1 gene overexpression characterizes a broader range of leukemic subtypes than previously thought, including various maturation stages of B-cell acute lymphoblastic leukemia and cytogenetic types additional to those involving the AML1 gene. © 2017, © The Author(s) 2017