1,720,999 research outputs found
Innovative strategies for a personalized therapy of β-thalassemia and sickle cell anemia
No full textLe emoglobinopatie sono difetti genetici ereditari che originano dal malfunzionamento della proteina adibita al trasporto dell’ossigeno, cioè l’emoglobina (Hb). Tra le emoglobinopatie, l’anemia falciforme (SCD) e la β-talassemia, malattie genetiche che coinvolgono il gene βglobinico, hanno il maggior impatto sulla mortalità e sullo stato patologico e affliggono milioni di persone nel mondo (Weatherall, 2010). Nella β-talassemia, il difetto a carico del gene β-globinico causa uno squilibrio tra le catene α- e β-globiniche nei globuli rossi (RBCs). Questa condizione porta al danno delle membrane cellulari dei globuli rossi, morte precoce ed eritropoiesi inefficace. L’anemia falciforme è dovuta ad una mutazione a cui consegue la sostituzione del sesto amminoacido della β-globina adulta. L’emoglobina che porta questa mutazione (HbS) polimerizza all’interno dei globuli rossi deformandoli e rendendoli più rigidi; questi globuli rossi a falce bloccano il flusso sanguigno nella microcircolazione compromettendo il rilascio dell’ossigeno nei tessuti. Le terapie correnti di queste patologie, oltre alle trasfusioni e alla somministrazione di ferro chelanti, prevedono il trattamento con Idrossiurea (HU), l’unico induttore di emoglobina fetale approvato dalla U.S. Food and Drug Administration (FDA). Ciononostante, la terapia con Idrossiurea raggiunge livelli di emoglobina fetale sufficienti solo nella metà dei pazienti (Steinberg et al., 1997) ed spesso vengono riportati effetti collaterali tra i quali la neutropenia e la leucopenia. Perciò, risulta necessario identificare nuovi induttori di emoglobina fetale per sviluppare una terapia personalizzata per i pazienti affetti da β-talassemia ed anemia falciforme. Complicazioni cliniche severe della β-talassemia e dell’anemia falciforme possono presentarsi rispettivamente in seguito all’accumulo di catene libere α-globiniche o alla produzione di catene β-globiniche difettose. Perciò abbiamo sperimentato la riduzione di emoglobine come potenziale pathway da colpire per sviluppare nuove terapie. La parte I di questa tesi è focalizzata sulla caratterizzazione di nuovi induttori di emoglobina fetale: 1) raccogliendo 33 campioni di sangue da diversi pazienti affetti da β-talassemia abbiamo dimostrato la capacità della Rapamicina di aumentare la produzione di emoglobina fetale, anche in cellule resistenti al trattamento con Idrossiurea; 2) durante la somministrazione di un integratore alimentare a base di Resveratrolo a pazienti β-talassemici abbiamo analizzato l’induzione del messaggero γ-globinico e la produzione di emoglobina fetale nei precursori eritroidi isolati dal sangue periferico; 3) abbiamo testato nuovi composti psoralenici valutando il grado di differenziamento eritroide in cellule eritroleucemiche umane K562 e osservato gli effetti sull’espressione dei geni globinici e sulla produzione di emoglobina fetale nei precursori eritroidi.
La parte II di questa tesi è volta a dimostrare l’applicazione terapeutica degli acido peptido nucleici (PNA) nelle cellule eritroidi: 1) abbiamo ottenuto un rilascio efficiente e veloce dei PNA nelle cellule eritroleucemiche umane mediante la coniugazione con una formulazione liposomica, senza evidenti effetti sulla proliferazione (Avitabile et al. 2015); 2) un PNA antisenso diretto contro il messaggero β-globinico è risultato capace di inibire la produzione di emoglobina nelle cellule eritroleucemiche murine (Montagner et al., 2015); 3) un PNA diretto contro la β-globina mutata è stato testato nei precursori eritroidi isolati da pazienti affetti da anemia falciforme.Hemoglobinopathies are genetic inherited defects that originate from the lack or malfunction of the hemoglobin (Hb) protein. Sickle cell disease (SCD) and β-thalassemia, both prototypical Mendelian single gene disorders affecting the β-globin gene have the most impact on morbidity and mortality, involving millions of people worldwide (Weatherall, 2010). β-thalassemia defects result in an imbalance accumulation of α- and β-globin proteins inside red blood cells (RBCs). This condition causes red cell membrane damage, early cell death, and ineffective erythropoiesis. SCD is due to a mutation that outcomes in a substitution of the sixth amino acid of adult β-globin. Hemoglobin tetramers bearing this mutation (HbS) polymerize inside RBCs and distort them; this rigid sickle RBCs can block blood vessels in the microcirculation compromising oxygen delivery to tissues. The current routines therapies, besides transfusion and iron chelation, include the treatment with Hydroxyurea (HU), the only fetal hemoglobin (HbF) inducer approved by the U.S. Food and Drug Administration (FDA). Despite this, treatments with HU generate sufficient levels of HbF in only half of patients (Steinberg et al., 1997) and side effects including leukopenia and neutropenia are frequently reported. Therefore, novel therapeutic inducers must be identified in order to develop a personalized treatment of patients with β-thalassemia and sickle cell anemia. Severe clinical complications of β-thalassemia and SCD may occur due to the accumulation of free α-globins or to the production of defective β-globin, respectively. Therefore, we investigated also the reduction of hemoglobin as a potential pathway to target for developing new therapies. Part I of this PhD thesis focuses on the characterization of novel fetal hemoglobin inducers: 1) by collecting 33 blood samples from different patients with β-thalassemia, we have demonstrated the action of Rapamycin to induce fetal hemoglobin production, even in HU-resistant cells; 2) during the in vivo administration to β-thalassemia patients of a Resveratrol-containing nutraceutical we have analyzed the expression of γ-globin mRNA and the production of fetal hemoglobin in erythroid precursors cells; 3) we have tested new psoralens analogues by evaluating the erythroid differentiation of K562 cells and the effects on globin genes expression and HbF production in erythroid precursors cells. Part II is concerned about the potential therapeutic application of peptide nucleic acids (PNAs) in erythroid cells: 1) in human erythroleukemia cells we obtained an efficient liposomemediated delivery of PNA with low antiproliferative activity (Avitabile et al. 2015); 2) an antisense PNA targeting β-globin mRNA was found to inhibit hemoglobin production in murine erythroleukemia cells (Montagner et al., 2015); 3) a PNA-anti-β-glob-SCA was tested in erythroid precursors cells isolated from SCD patients
Cytokines profile and peripheral blood mononuclear cells morphology in Rett and autistic patients
No full textA potential role for immune dysfunction in autism spectrum disorders (ASD) has been well established. However, immunological features of Rett syndrome (RTT), a genetic neurodevelopmental disorder closely related to autism, have not been well addressed yet. By using multiplex Luminex technology, a panel of 27 cytokines and chemokines was evaluated in serum from 10 RTT patients with confirmed diagnosis of MECP2 mutation (typical RTT), 12 children affected by classic autistic disorder and 8 control subjects. The cytokine/chemokine gene expression was assessed by real time PCR on mRNA of isolated peripheral blood mononuclear cells (PBMCs). Moreover, ultrastructural analysis of PBMCs was performed using transmission electron microscopy (TEM). Significantly higher serum levels of interleukin-8 (IL-8), IL-9, IL-13 were detected in RTT compared to control subjects, and IL-15 shows a trend toward the upregulation in RTT. In addition, IL-1β and VEGF were the only down-regulated cytokines in autistic patients with respect to RTT. No difference in cytokine/chemokine profile between autistic and control groups was detected. These data were also confirmed by ELISA real time PCR. At the ultrastructural level, the most severe morphological abnormalities were observed in mitochondria of both RTT and autistic PBMCs. In conclusion, our study shows a deregulated cytokine/chemokine profile together with morphologically altered immune cells in RTT. Such abnormalities were not quite as evident in autistic subjects. These findings indicate a possible role of immune dysfunction in RTT making the clinical features of this pathology related also to the immunology aspects, suggesting, therefore, novel possible therapeutic interventions for this disorder
MicroRNA miR-93-5p regulates expression of IL-8 and VEGF in neuroblastoma SK-N-AS cells
No full textThe role of the microRNA miR-93-5p on the secretome profile and the expression levels of vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) was investigated in the neuroblastoma SK-N-AS cell line by Bio-Plex analysis and RT-qPCR. The results indicate that VEGF and IL-8 are the major miR-93-5p molecular targets. This conclusion was based on in vitro transfection with pre-miR-93-5p and anti-miR-93-5p; these treatments inversely modulated both VEGF and IL-8 gene expression and protein release in the neuroblastoma SK-N-AS cell line. Computational analysis showed the presence of miR-93-5p consensus sequences in the 3'UTR region of both VEGF and IL-8 mRNAs, predicting possible interaction with miR-93-5p and confirming a potential regulatory role of this microRNA
Human amniotic membrane: an improvement in the treatment of Medication-related osteonecrosis of the jaw (MRONJ)? A case–control study
Full text linkThe aim of this article is to report the results obtained by the use of HAM in surgical wound healing and the reduction of relapse in patients affected by Medication-related osteonecrosis of the jaw (MRONJ).The study involved patients with the diagnosis of MRONJ, surgically treated between October 2016 and April 2019, in a case-control setting. Enrolled patients were randomly divided into 2 groups. One group will be treated with resective surgery and with the insertion of HAM patch (Group A), while the second group had been treated exclusively with resective surgery (Group B).The patients underwent MRONJ surgical treatment with the placement of amniotic membrane patches at the wound site. Data regarding the long-term complications/functions were evaluated at 3, 6, 12, and 24months after surgery. Pain measurements were performed before the intervention (T0), 7(T1) and 30(T2) days after surgery. 49 patients were included in the study. 2 patients of GROUP A after 30days since they were surgically treated showed persistent bone exposure. 5 patients of group B demonstrated a lack of healing of the surgical wound with the persistence of bone exposed to 30days after surgery. Statistical analysis ruled out any difference in OUTCOME (relapse) between GROUP A and B (p=0.23). However, the Fisher test highlighted a significant difference between the use of HAM and only surgical treatment in pain at rest (p=0.032). The use of amniotic membrane implement the patient's quality of life and reduce pain perception. has a learning curve that is fast enough to justify its routine use
Phloridzin derivatives inhibiting proinflammatory cytokine expression in human cystic fibrosis IB3-1 cells
No full textCystic Fibrosis (CF) is the most diffuse autosomal recessive genetic disease present in caucasian people. A persistent recruitment of neutrophils in the bronchi of CF patients contributes to exacerbate the airway tissue damage, suggesting the importance of modulating the expression of chemokines during the patient management. The identification of innovative anti-inflammatory drugs is considered a therapeutic target to prevent the progressive tissue deterioration1. Phloridzin, isolated from Malus domestica by a selective Molecular Imprinting extraction, and its structural analogues, Phloridzin eptaproprionate (F1) and Phloridzin tetraproprionate (F2)2, have been firstly investigated to discover their ability in reducing mainly IL-6 and IL-8 expression, released from CF cells under the control of the NF-kB Transcription Factor (TF), in human CF bronchial epithelial cells (IB3-1) stimulated with TNF-α. Among all the derivatives tested, F2 was the most interesting, demonstrating inhibitory effects also on the expression and production of different cytokines involved in CF inflammation processes, including RANTES, VEGF, GM-CSF, IL-12, G-CSF, MIP-1b, IL-17, IL-10 and IP-10, without any correlated anti- proliferative and pro-apoptotic effects
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
