338 research outputs found
The molecular chaperone Hsp90 is a component of the cap-binding complex and interacts with the translational repressor Cup during Drosophila oogenesis
In metazoa, the spatio-temporal translation of diverse mRNAs is essential to guarantee proper oocyte maturation and early embryogenesis. The eukaryotic translation initiation factor 4E (eIF4E), which binds the 5′ cap structure of eukaryotic mRNAs, associates with either stimulatory or inhibitory factors to modulate protein synthesis. In order to identify novel factors that might act at the translational level during Drosophila oogenesis, we have undertaken a functional proteomic approach and isolated the product of the Hsp83 gene, the evolutionarily conserved chaperone Hsp90, as a specific component of the cap-binding complex. Here we report that Hsp90 interacts in vitro with the translational repressor Cup. In addition, we show that Hsp83 and cup interact genetically, since lowering Hsp90 activity enhances the oogenesis alterations linked to diverse cup mutant alleles. Hsp90 and Cup co-localize in the cytoplasm of the developing germ-line cells within the germarium, thus suggesting a common function from the earliest stages of oogenesis. Taken together, our data start elucidating the role of Hsp90 during Drosophila female germ-line development and strengthen the idea that Cup has multiple essential functions during egg chamber development
Contractarian Compliance and the 'Sense of Justice': A Behavioral Conformity Model and Its Experimental Support
The social contract approach to the study if institutions aims at providing a solution to the problem of compliance with rational agreements in situations characterized by a conflict between individual rationality and social optimality. After a short discussion of some attempts to deal with this problem from a rational choice perspective, we focus on John Rawls's idea of 'sense of justice' and its application to the explanation of the stability of a well-ordered society. We show how the relevant features of Rawls's theory can be captured by a behavioral game theory model of beliefs-dependent dispositions to comply, and we present the results of two experimental studies that provide support to the theory
Compliance by Believing : An Experimental Exploration on Social Norms and Impartial Agreements
The main contribution of this paper is twofold. First of all, it focuses on the decisional process that leads to the creation of a social norm. Secondly, it analyses the mechanisms through which subjects conform their behaviour to the norm. In particular, our aim is to study the role and the nature of Normative and Empirical Expectations and their influence on people's decisions. The tool is the Exclusion Game, a sort of 'triple mini-dictator game'. It represents a situation where 3 subjects - players A - have to decide how to allocate a sum S among themselves and a fourth subject - player B - who has no decisional power. The experiment consists of three treatments. In the Baseline Treatment participants are randomly distributed in groups of four players and play the Exclusion Game. In the Agreement Treatment in each group participants are invited to vote for a specific non-binding allocation rule before playing the Exclusion Game. In the Outsider Treatment, after the voting procedure and before playing the Exclusion Game, a player A for each group (the outsider) is reassigned to a different group and instructed about the rule chosen by the new group. In all the treatments, at the end of the game and before players are informed about the decisions taken during the Exclusion Game by the other co-players, first order and second order expectations (both normative and empirical) are elicited through a brief questionnaire. The first result we obtained is that subjects' choices are in line with their empirical (not normative) expectations. The second result is that even a non-binding agreement induces convergence of empirical expectations - and, consequently, of choices. The third results is that expectation of conformity is higher in the partner protocol. This implies that a single outsider breaks the 'trust an
Beyond lockdown: The potential side effects of the sars-cov-2 pandemic on public health
Lockdowns to contain the spread of the SARS-CoV-2 have disrupted routines and behaviors, which could lead to a worsening of lifestyle and an increase in the burden of non-communicable diseases. This study aimed to describe the changes in physical activity, diet, alcohol drinking, and cigarette smoking during lockdown. A self-administered online survey addressing adults living in a province in northern Italy was advertised through websites and social media. Citizens could access the survey in anonymity from 4 May until 15 June 2020. A total of 1826 adults completed the survey, with a worsening of physical activity (35.1%), diet (17.6%), alcohol drinking (12.5%), and cigarette smoking (7.7%) reported. In contrast, 33.5% reported an improvement in diet, 12.6% in alcohol drinking, 5.3% in physical activity and 4.1% in cigarette smoking. Female sex, young adult age, suspension of work activity, and symptoms of psychological distress were the factors associated with a greater likelihood of change, which was frequently for the worse. Lockdown had an impact on lifestyle, with some net beneficial effects on diet and mostly negative effects on physical activity. Public health measures should be implemented to avoid long-term negative effects of the lockdown, supporting individuals more prone to change for the worse
Follow-Up CT Patterns of Residual Lung Abnormalities in Severe COVID-19 Pneumonia Survivors: A Multicenter Retrospective Study
Prior studies variably reported residual chest CT abnormalities after COVID-19. This study evaluates the CT patterns of residual abnormalities in severe COVID-19 pneumonia survivors. All consecutive COVID-19 survivors who received a CT scan 5–7 months after severe pneumonia in two Italian hospitals (Reggio Emilia and Parma) were enrolled. Individual CT findings were retrospectively collected and follow-up CT scans were categorized as: resolution, residual non-fibrotic abnormalities, or residual fibrotic abnormalities according to CT patterns classified following standard definitions and international guidelines. In 225/405 (55.6%) patients, follow-up CT scans were normal or barely normal, whereas in 152/405 (37.5%) and 18/405 (4.4%) patients, non-fibrotic and fibrotic abnormalities were respectively found, and 10/405 (2.5%) had post-ventilatory changes (cicatricial emphysema and bronchiectasis in the anterior regions of upper lobes). Among non-fibrotic changes, either barely visible (n = 110/152) or overt (n = 20/152) ground-glass opacities (GGO), resembling non-fibrotic nonspecific interstitial pneumonia (NSIP) with or without organizing pneumonia features, represented the most common findings. The most frequent fibrotic abnormalities were subpleural reticulation (15/18), traction bronchiectasis (16/18) and GGO (14/18), resembling a fibrotic NSIP pattern. When multiple timepoints were available until 12 months (n = 65), residual abnormalities extension decreased over time. NSIP, more frequently without fibrotic features, represents the most common CT appearance of post-severe COVID-19 pneumonia
The Anti-Leukemia Effect of Ascorbic Acid: From the Pro-Oxidant Potential to the Epigenetic Role in Acute Myeloid Leukemia
Data derived from high-throughput sequencing technologies have allowed a deeper understanding of the molecular landscape of Acute Myeloid Leukemia (AML), paving the way for the development of novel therapeutic options, with a higher efficacy and a lower toxicity than conventional chemotherapy. In the antileukemia drug development scenario, ascorbic acid, a natural compound also known as Vitamin C, has emerged for its potential anti-proliferative and pro-apoptotic activities on leukemic cells. However, the role of ascorbic acid (vitamin C) in the treatment of AML has been debated for decades. Mechanistic insight into its role in many biological processes and, especially, in epigenetic regulation has provided the rationale for the use of this agent as a novel anti-leukemia therapy in AML. Acting as a co-factor for 2-oxoglutarate-dependent dioxygenases (2-OGDDs), ascorbic acid is involved in the epigenetic regulations through the control of TET (ten-eleven translocation) enzymes, epigenetic master regulators with a critical role in aberrant hematopoiesis and leukemogenesis. In line with this discovery, great interest has been emerging for the clinical testing of this drug targeting leukemia epigenome. Besides its role in epigenetics, ascorbic acid is also a pivotal regulator of many physiological processes in human, particularly in the antioxidant cellular response, being able to scavenge reactive oxygen species (ROS) to prevent DNA damage and other effects involved in cancer transformation. Thus, for this wide spectrum of biological activities, ascorbic acid possesses some pharmacologic properties attractive for anti-leukemia therapy. The present review outlines the evidence and mechanism of ascorbic acid in leukemogenesis and its therapeutic potential in AML. With the growing evidence derived from the literature on situations in which the use of ascorbate may be beneficial in vitro and in vivo, we will finally discuss how these insights could be included into the rational design of future clinical trials
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