1,721,017 research outputs found
Phthalate esters: bioaccumulation and intracellular signal modifications in in vivo and in vitro models
No full textPhthalate esters: Bioaccumulation and intracellular signal modifications in in vivo and in vitro models
No full textPhthalates, a class of chemicals used in a whole range of industrial applications, are considered to be ubiquitous global contaminants and endocrine disruptors (EDs). These hormone-mimicking compounds bioaccumulate within organ tissues in several animals, including fishes, amphibians and mammals with different and selective patterns of distribution. The endocrine disrupting effects are probably related to the absorption of these chemicals via the alimentary canal. In particular, phthalates have been seen to be stored in the oxyntic cells of the gastric tubular glands in fishes and amphibians. A relation between bioconcentration and organ functions was also observed. Moreover, in vitro studies on rat osteoblastic cultures demonstrated that benzyl butyl phthalate and di-n-butyl phthalate bioaccumulate, modify actin cytoarchitecture and exert mitogenic effects involving microfilament disruption and nuclear actin/lamin A regulation. On the other hand, primary mouse calvarial osteoblasts, treated with the above chemicals showed DNA base lesions with an increase of apoptotic markers induced by the p53-related pathway. These data strongly suggest that chronic exposure to phthalates could probably affect new bone formation and matrix deposition with clinical implications on bone homeostasis and mineral density. Understanding the way of action of phthalates through the study of autochthon or laboratory animals could reveal the mechanism by which these compounds, as EDs, regulate the fate of the organism
Materiali elettroattivi per applicazioni Biomediche
No full textMateriali elettroattivi per applicazioni Biomedich
Tackling Inequalities in Oral Health: Bone Augmentation in Dental Surgery through the 3D Printing of Poly(ε-caprolactone) Combined with 20% Tricalcium Phosphate
No full textThe concept of personalized medicine and overcoming healthcare inequalities have become extremely popular in recent decades. Polymers can support cost reductions, the simplicity of customized printing processes, and possible future wide-scale expansion. Polymers with β-tricalcium phosphate (TCP) are well known for their synergy with oral tissues and their ability to induce osteoconductivity. However, poor information exists concerning their properties after the printing process and whether they can maintain an unaffected biological role. Poly(ε-caprolactone) (PCL) polymer and PCL compounded with TCP 20% composite were printed with a Prusa Mini-LCD-®3D printer. Samples were sterilised by immersion in a 2% peracetic acid solution. Sample analyses were performed using infrared-spectroscopy and statical mechanical tests. Biocompatibility tests, such as cell adhesion on the substrate, evaluations of the metabolic activity of viable cells on substrates, and F-actin labelling, followed by FilaQuant-Software were performed using a MC3T3-E1 pre-osteoblasts line. PCL+β-TCP-20% composite is satisfactory for commercial 3D printing and appears suitable to sustain an ISO14937:200937 sterilization procedure. In addition, the proper actin cytoskeleton rearrangement clearly shows their biocompatibility as well as their ability to favour osteoblast adhesion, which is a pivotal condition for cell proliferation and differentiation
Role of PTH in Bone Marrow Niche and HSC Regulation
Full text linkPurpose of Review. The bone marrow microenvironment hosts a multicellular complex that is extraordinary in its interdependence and function. The composite machinery within the axial and long bones is involved in the homing, maintenance, differentiation, and egress of hematopoietic/ progenitors stem cells (HSCS) as well as mesenchymal/ stromal stem cells (MSCs) that dwell in specific anatomical areas inside the marrow space, described as niches. The need for more efficient hematopoietic stem cell transplantation protocols and bonemarrow manipulation techniques has motivated scientists to identify effective niche regulators such as the parathyroid hormone (PTH). Recent Findings PTH treatment is increasingly used with promising outcomes in autologous and allogeneic transplantation of HSCs, because PTH operates as a significant mediator in HSC engraftment, expansion, and mobilization. In addition to the well-established anti-osteoporotic effect of PTH, there is evidence that it may also coordinate hematopoietic stem cell activities.
Summary. This report provides up-to-date information about PTH action within marrow niches and highlights the importance of this hormone in the behavior of hematopoietic elements in the bone marrow
P62/SQSTM1 beyond Autophagy: Physiological Role and Therapeutic Applications in Laboratory and Domestic Animals
Full text linkInflammation is the preceding condition for the development of mild and severe pathological conditions, including various forms of osteopenia, cancer, metabolic syndromes, neurological disorders, atherosclerosis, cardiovascular, lung diseases, etc., in human and animals. The inflammatory status is induced by multifarious intracellular signaling cascades, where cytokines, chemokines, arachidonic acid metabolites, adhesion molecules, immune cells and other components foster a “slow burn” at a local or systemic level. Assuming that countering inflammation limits the development of inflammation-based diseases, a series of new side-effects-free therapies was assessed in experimental and domestic animals. Within the targets of the drug candidates for quenching inflammation, an archetypal autophagic gear, the p62/sqstm1 protein, has currently earned attention from researchers. Intracellular p62 has been recently coined as a multi-task tool associated with autophagy, bone remodeling, bone marrow integrity, cancer progression, and the maintenance of systemic homeostasis. Accordingly, p62 can act as an effective suppressor of inflamm-aging, reducing oxidative stress and proinflammatory signals. Such an operational schedule renders this protein an effective watchdog for degenerative diseases and cancer development in laboratory and pet animals. This review summarizes the current findings concerning p62 activities as a molecular hub for cell and tissues metabolism and in a variety of inflammatory diseases and other pathological conditions. It also specifically addresses the applications of exogenous p62 (DNA plasmid) as an anti-inflammatory and homeostatic regulator in the treatment of osteoporosis, metabolic syndrome, age-related macular degeneration and cancer in animals, and the possible application of p62 plasmid in other inflammation-associated diseases
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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