1,720,969 research outputs found
In vitro peripheral blood mononuclear cells sensitivity to steroids and identification of biomarkers for predicting clinical response in pediatric idiopathic nephrotic syndrome
No full textIdiopathic nephrotic syndrome (INS) is the most common pediatric glomerulopathy (annual incidence: 2.7 cases/100.000 subjects aged 0-14 years), with a prevalence of 16 per 100.000 pediatric subjects. The therapy with prednisone is able to induce remission in 85-90% of children at onset, however, about 50% of them show frequent relapses, with the use of high doses of steroids, which involve inevitable side effects. To date, the optimal dose of steroids to be used in the first episode of INS has not been defined: the identification of biomarkers able to predict the sensitivity to glucocorticoids (GC) a priori could provide a useful tool to improve INS treatment and may be useful for developing an individualized therapy in these patients.
With this background, the aim of the thesis was to identify the cellular and molecular markers associated with and predictive of outcome in pediatric INS.
For this purpose, it has been developed a pharmacodynamic assay, to predict the sensitivity to GC in vitro and to assess the possible association between the clinical and the in vitro response in pediatric patients with INS. Preliminary studies were carried out to evaluate the associations between the clinical or the in vitro response and the presence of different genetic polymorphisms, the levels of expression of the GC receptor and of other proteins involved in the mechanism of action of GC, as well as of the long non coding RNA GAS-5 that has been found to regulate GC response. Moreover, the plasma levels of cytokines at disease onset and after 4 weeks of prednisone treatment were also evaluated.
The studies in this thesis have hypothesized several candidates to predict GC response in children with INS, the results, being based on non-invasive methods, could lead to a turnaround in current treatment in childhood INS and could be relevant also for other pediatric populations treated with steroids.Idiopathic nephrotic syndrome (INS) is the most common pediatric glomerulopathy (incidence: 2.7 cases/year/100.000 subjects aged 0-14 years), with a prevalence of 16 per 100.000 pediatric subjects. The therapy with prednisone is able to induce remission in 85-90% of children at onset, however between the sensitive patients, 50% shown frequent relapses, with the use of high doses of steroids, which involve inevitable side effects . To date, however, the optimal dose of steroids to be used in the first episode of INS has not been defined yet: the identification of biomarkers to predict the sensitivity to glucocorticoids (GC) a priori could provide a clearer picture in the treatment of INS and may be useful in developing an individualized therapy in these patients.
With this background, the aim of the thesis was to identify the cellular and molecular markers associated with and / or predictive of outcome in pediatric INS.
For this purpose, it has been developed a pharmacodynamic tests in vitro, to predict the sensitivity to GC and assess the possible associations between the clinical and in vitro response of pediatric patients with INS. The plasma levels of cytokines were also evaluated, in order to identify a biomarker useful in the prediction of GC response. Moreover, preliminary studies were carried out to evaluate the possible associations between the clinical and the in vitro response with the presence of different genetic polymorphisms, with the levels of expression of the GC receptor and the role of an long non coding RNA, and the mRNA expression levels of proteins involved in the mechanism of action of GC.
The studies in this thesis have hypothesized several methods to predict GC response in children with INS, the results, being based on non-invasive methods, could really cause a turnaround in current treatment in childhood INS and could be relevant also for other pediatric populations
Reappraisal of Antimalarials in Interferonopathies: New Perspectives for Old Drugs
Full text linkThe story of antimalarials as antinflammatory drugs dates back several centuries. Chinin, the extract of the Cinchona bark, has been exploited since the 18th century for its antimalarial and antifebrile properties. Later, during the Second World War, the broad use of antimalarials allowed arguing their antirheumatic effect on soldiers. Since then, these drugs have been broadly used to treat Systemic Lupus Erythematosus, but, only recently, have the molecular mechanisms of action been partly clarified. Inhibitory action on vacuole function and trafficking has been considered for decades the main mechanism of the action of antimalarials, affecting the activation of phagocytes and dendritic cells. In addition, chloroquine is also known as a potent inhibitor of autophagy, providing another possible explanation of its antinflammatory action. However, much attention has been recently devoted to the action of antimalarials on the so-called cGAS-STING pathway leading from the sensing of cytoplasmic nucleic acids to the production of type I interferons. This pathway is a fundamental mechanism of host defence, since it is able to detect microbial DNA and induce the type I interferon-mediated immune response. Of note, genetic defects in the degradation of nucleic acids lead to inappropriate cGAS-STING activation and inflammation. These disorders, called type I interferonopathies, represent a valuable model to study the antinflammatory potential of antimalarials. We will discuss possible development of antimalarials to improve the treatment of type I interferonopathies and likely multifactorial disorders characterised by interferon inflammation, such as Systemic Lupus Erythematosus
Differential action of 3-hydroxyanthranilic acid on viability and activation of stimulated lymphocytes.
No full textLymphocytes proliferation after antigen-driven activation leads to an increase in cell count, which could last some week, until apoptosis mechanisms allow the homeostatic control of the system. During the first days of this stimulation, activated lymphocytes display high resistance to apoptosis and to most immunosuppressive drugs. According to the literature, few compounds have been described to kill recently activated cells, by inhibiting metabolic processes fundamental to proliferation.
The aim of our work was to evaluate comparatively these different compounds, in order to identify the best strategy to kill cells that have undergone proliferation, while sparing the repertoire of resting cells.
After preliminary experiments, 3-HAA and bortezomib were selected as the most suitable compounds for our purposes. The possible synergic effect of 3-HAA with bortezomib or with manganese ions was also assessed.
3-HAA was confirmed to be the most reliable pharmacologic approach to inhibit proliferation with acceptable toxicity on resting cells. While in the case of PHA stimulation 3-HAA led to death of most lymphocytes, only a minor percentage of cells were killed after allo-stimulation, suggesting that the effect is proportional to the percentage of stimulated lymphocytes. Manganese ions further enhanced this effect, while results with bortezomib seemed to be less consistent.
These results deserve further investigations to develop new procedures for targeting activated cells with pharmacological approaches
Association between BclI polymorphism in the NR3C1 gene and in vitro individual variations in lymphocyte responses to methylprednisolone.
No full textWHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: In vitro lymphocyte steroid sensitivity has been suggested as a useful tool to predict in vivo response to glucocorticoid treatment in different inflammatory chronic diseases. A correlation between genetic polymorphisms and clinical response to glucocorticoids has been demonstrated in these patients.
WHAT THIS STUDY ADDS:
The BclI polymorphism in the glucocorticoid receptor (NR3C1) gene is associated with higher methylprednisolone potency in vitro. The combined evaluation of the in vitro sensitivity to methylprednisolone and BclI polymorphism could represent an aid for physicians to adjust therapy a priori. AIM To evaluate the association between the in vitro sensitivity of peripheral blood mononuclear cells (PBMCs) to methylprednisolone (MP) and the presence of genetic polymorphisms involved in glucocorticoid (GC) response.
METHODS:
In vitro MP inhibition of the proliferation of lymphocytes stimulated with concanavalin A was determined. Non linear regression of dose-response data was performed computing the MP concentration required to reduce proliferation to 50% (IC(50) ). The maximum inhibition achievable at the highest MP concentration (I(max) ) was also calculated. Moreover, the Taqman technique was used to analyze the BclI polymorphism in the NR3C1 gene and the Leu155His polymorphism in the NALP1 gene.
RESULTS:
A significant association between the BclI mutated genotype and an increased in vitro sensitivity to GCs was observed.
CONCLUSIONS:
The a priori evaluation of the BclI polymorphism, associated with a lymphocyte proliferation assay, could represent a useful diagnostic tool for the optimization of steroid treatment
Pharmacogenetics of azathioprine in inflammatory bowel disease: A role for glutathione-S-transferase?
No full textAzathioprine is a purine antimetabolite drug commonly used to treat inflammatory bowel disease (IBD). In vivo it is active after reaction with reduced glutathione (GSH) and conversion to mercaptopurine. Although this reaction may occur spontaneously, the presence of isoforms M and A of the enzyme glutathione-S-transferase (GST) may increase its speed. Indeed, in pediatric patients with IBD, deletion of GST-M1, which determines reduced enzymatic activity, was recently associated with reduced sensitivity to azathioprine and reduced production of azathioprine active metabolites. In addition to increase the activation of azathioprine to mercaptopurine, GSTs may contribute to azathioprine effects even by modulating GSH consumption, oxidative stress and apoptosis. Therefore, genetic polymorphisms in genes for GSTs may be useful to predict response to azathioprine even if more in vitro and clinical validation studies are needed
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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