291 research outputs found
Thrombophilia, systemic inflammation and prevention of cardiovascular disease in children and adolescents with HIV infection
No full textLa malattia aterosclerotica inizia già dalla seconda decade di vita. Insieme ai tradizionali fattori di rischio associati (fumo, colesterolo, ipertensione) negli ultimi anni si è andata caratterizzando il ruolo dell’infiammazione, risultata, da studi di base confermati da numerose osservazioni cliniche, una componente patogenetica rilevante nell’insorgenza e progressione della lesione aterosclerotica.
Patologie associate ad infiammazione sistemica come il Lupus Eritematoso o la malattia di Kawasaki sono considerate condizioni a rischio moderato di aterosclerosi in età pediatrica. Anche l’infezione da HIV si associa ad alti livelli di infiammazione sistemica, fattore con un ruolo riconosciuto da tempo nell’accelerare l’immunodeficienza caratteristica della malattia. L’introduzione della cART (terapia antiretrovirale di combinazione) ha consentito negli ultimo 15 anni una riduzione straordinaria dell’incidenza di malattie opportunistiche associate all’AIDS (Sindrome da Immunodeficienza Acquisita), e una riduzione della mortalità, ma si è contemporaneamente assistito ad un aumento dell’incidenza di malattie non associate ad immunodeficienza, tra cui un ruolo principale è costituito dall’aterosclerosi e alle altre malattie cardiovascolari associate alla trombosi.
Nell’adulto un recente trial randomizzato (SMART trial) ha mostrato che la replicazione virale incontrollata risulta essere un fattore di rischio non solo per la progressione dell’immunodeficienza, ma anche per l’incidenza e mortalità da malattia cardiovascolare. Il ruolo dell’infezione da HIV come fattore di rischio per l’aterosclerosi e le malattie cardiovascolari è poco conosciuto in età pediatrica, popolazione in cui, anche se è minore l’incidenza di manifestazioni cliniche, tale indagine è resa più appropriata per il minore ruolo concomitante di altri fattori confondenti (es. ipertensione, iperglicemia).
In una prima fase del progetto di ricerca è stata indagata la prevalenza in bambini ed adolescenti con infezione da HIV seguiti presso l’Ospedale Pediatrico Bambino Gesù di Roma, della sindrome metabolica (ipercolesterolemia, iperglicemia, ipertrigliceridemia), già descritta e caratterizzata nei pazienti adulti con infezione da HIV in trattamento con farmaci antiretrovirali.
Successivamente, e per la prima volta, è stata indagata l’associazione tra replicazione virale, infiammazione sistemica e anomalie della coagulazione (trombofilia) in una coorte di bambini e adolescenti con infezione da HIV, producendo dati originali pubblicati nel Febbraio 2010 (Pontrelli et al, AIDS).
Sono stati studiati i livelli di attività della proteina S e proteina C anticoagulante e dell’antitrombina, insieme con il fibrinogeno, il D-dimero, la proteina C-reattiva e l’omocisteina. L’ipotesi che la viremia HIV determinasse aumento dei markers di infiammazione e alterazione dei markers di coagualazione è stata verificata confrontando i valori in pazienti con alta viremia (HVL, High Viral Load: HIV-RNA>1000 copie/mL) con i valori dei pazienti a bassa viremia (Low Viral Load, LVL: HIV-RNA<1000 copie/mL).
All’analisi univariata è seguita un’analisi multivariata che ha valutato il ruolo di altre variabili demografiche, cliniche e terapeutiche potenzialmente confondenti. Sono stati arruolati un totale di ottantotto pazienti (età media 13.5 anni, CD4 medi 30%, 72% pazienti nel gruppo LVL).
Lo studio ha evidenziato un deficit di proteina S e C anticoagulante rispettivamente del 51 e 8%. I pazienti nel gruppo HVL hanno presentato una riduzione significativa dei livelli di proteina S, proteina C e antitrombina, ed un aumento dei livelli di D-dimero.
La riduzione di proteina S (-11.2%, P=0.04) e l’aumento di D-dimero (+0.13mg/ml, P=0.004) sono risultati associati in maniera indipendente con l’alta viremia anche nell’analisi multivariata.
In conclusione lo studio ha dimostrato che in era cART, bambini ed adolescenti con infezione da HIV presentano un’alta prevalenza di alterazioni trombofiliche. L’analisi multivariata ha mostrato che la replicazione virale si associa in maniera significativa ed indipendente alla diminuizione della proteina S anticoagulante e all’aumento di D-dimero, suggerendo il vantaggio della terapia soppressiva sul mantenimento dell’omeostasi coagulativa e l’opportunità di una prevenzione attiva di tutti i fattori di rischio cardiovascolari a partire dall’età pediatrica.Atherosclerosis begins early in the lifetime and, as for other cardiovascular diseases associated with thrombosis, appears more relevant and anticipated in HIV-infected patients after combination antiretroviral therapy (cART) has reduced AIDS-related diseases and has improved survival.
Systemic chronic inflammation, a condition associated with HIV, could have a role in determining anticipated cardiovascular diseases since it is a risk factor for atherosclerosis. The association between viral replication, inflammation and coagulation abnormalities in a cohort of HIV-infected children and adolescents was investigated as aim of this research project.
In a first part of the research, prevalence of metabolic syndrome (hyper-cholesterolemia, hyper-trigliceridemia, hyper-glicemia), well characterized in adults on antiretroviral treatment, was studied in the cohort of children and adolescents. In the second part, assays on thrombophilia (protein S, protein C anticoagulant and antithrombin activity), were done together with fibrinogen, D-dimer, high-sensitive C-reactive protein, homocysteine and metabolic exams.
Patients with high viral load (HVL, HIV-RNA>1000 copies/ml) were compared with those in patients with a lower replication (LVL), adjusting for other demographic, clinical and therapeutic covariates. Eighty-eight patients (mean age 13.5 years, CD4 30%, 72% with LVL) were enrolled. A prevalence of protein S and protein C deficiency of 51 and 8% was, respectively, found. HVL group compared to LVL showed a significant reduction of protein S, protein C and antithrombin activities, and an increase of D-dimer levels. The independent association of HVL with decreased protein S activity (-11.2%, P=0.04) and increased D-dimer levels (+0.13mg/ml, P=0.004) was confirmed in the multivariate model.
In conclusion HIV-infected children and adolescents present high prevalence of thrombophilic abnormalities. The multivariate model confirmed that high viral replication is independently associated with decrease of protein S and increase of D-dimer, suggesting the advantage of suppressive therapy on coagulation homeostasis and the opportunity of an active control of cardiovascular risk factors starting at a younger age
Cytotoxic T Lymphocytes (CTLs) and Kidney Transplantation: An Overview
No full textInvolvement of T lymphocytes in kidney transplantation is a well-developed topic; however, most of the scientific interest focused on the different type of CD4+ lymphocyte subpopulations. Few authors, instead, investigated the role of CD8+ T cells in renal transplantation and how deleterious they can be to long-term allograft survival. Recently, there has been a renewed interest in the CD8+ T cells involvement in the transplantation field with the aim to investigate the immunological mechanisms underlying the infiltration of CD8+ T cells and their biological functions in human kidney allografts. The purpose of the present review is to highlight the role of allo-reactive cytotoxic T lymphocytes (CTLs) CD8+ subset in allograft kidney recipients and their related clinical complications
A one-dimensional Model for Blood Flow in Prestressed Vessels
No full textWe are interested in developing a simple model to investigate blood-vessel interactions in a finite arterial segment of the cardiovascular tree. For this purpose, we developed a continuum model for a vascular segment, and we coupled it with a discrete model for the remaining systemic circulation. In working out the modeling, we addressed some main issues, such as the nonlinearity of blood flow, the compliance of the vessel and the prestress state of the artery walls, that is always present aside from the filling of blood. Moreover, we set a discrete model capable of providing appropriate boundary conditions to the continuum model, by reproducing the proper waveforms entering the vessel and avoiding spurious reflections
A chemo-mechano-biological formulation for the effects of biochemical alterations on arterial mechanics: the role of molecular transport and multiscale tissue remodelling
No full textThis paper presents a chemo-mechano-biological framework for arterial physiopathology. The model accounts for the fine remodelling in the multi- scale hierarchical arrangement of tissue constituents and for the diffusion of molecular species involved in cell–cell signalling pathways. Effects in terms of alterations in arterial compliance are obtained. A simple instructive example is introduced. Although oversimplified with respect to realistic case studies, the proposed application mimics the biochemical activity of matrix metallo- proteinases, transforming growth factors beta and interleukins on tissue remodelling. Effects of macrophage infiltration, of intimal thickening and of a healing phase are investigated, highlighting the corresponding influence on arterial compliance. The obtained results show that the present approach is able to capture changes in arterial mechanics as a consequence of the alterations in tissue biochemical environment and cellular activity, as well as to incorporate the protective role of both autoimmune responses and pharmacological treatments
Analysis of miRNA Expression Using Digital and the
No full textmiRNAs are short, single-stranded RNA molecules that function as posttranscriptional regulators of gene expression. miRNAs represent ideal biomarkers since they can also circulate in the bloodstream as well as in other biological fluids such as urine, saliva, and cerebrospinal fluid.miRNAs play an important role in the regulation of immune cells including cytotoxic T-lymphocytes. Circulating miRNAs can be analyzed by Real-Time PCR or microarray profiling; however data normalization represents still an unsolved problem due to the lack of widely validated house-keeping miRNAs candidates.Digital PCR (dPCR) is an end-point PCR method that is used for absolute quantification. In this chapter we will describe the applications of Digital PCR for the analysis of miRNAs that can influence immune response in serum samples and we will report a specific protocol that can be used to analyze miRNAs using the QuantStudioTM 3D Digital PCR System. The advantage of this method consists in the possibility to highlight weaker differences in miRNA circulating molecules that can be useful to monitor CTLs behavior in pathological conditions or after therapeutic intervention
EMPOWERING CHANGE FROM WITHIN: A HUMAN-CENTERED APPROACH TO DIGITAL TRANSFORMATION IN AN ITALIAN FOOD SECTOR SME
No full textPurpose – This study explores the challenges posed by digital transformation in the food sector, focusing on the strategic role of human resources (HR) as enablers of technological change. Using the theoretical lens of organisational rent, it analyses how sustainability-oriented – particularly socially oriented – HR practices facilitate digital adoption and enhance organisations’ economic and social performance.
Design/methodology/approach – Adopting a qualitative single-case methodology, the research focuses on Geldi S.p.A., an Italian family-owned small and medium-sized enterprise (SME) in the food service sector, distinguished by an HR-driven approach to digital transformation. The analysis draws on primary data – semi-structured interviews with Geldi’s HR Manager and the Executive Director of the Abruzzo-Molise Food Bank, plus informal conversations with several employees – and on secondary data (recent sustainability reports, corporate websites, official social-media channels, and press coverage) to examine the interplay between implemented digital technologies and HR management practices.
Findings – Digital transformation in food-sector organizations often encounters cultural resistance, skill shortages, and operational strain. Geldi addresses these barriers through a participatory, bottom-up strategy that leverages social-sustainability initiatives to foster employee engagement, thereby facilitating technology integration while improving organisational climate and economic–social performance.
Originality – The study presents a human-centred model of digital transformation in which the HR function assumes a proactive, strategic role, enriching the literature on food-sector digital transformation and the emerging field of social sustainability. It advances theoretical knowledge by integrating the organisational rent perspective with Intellectual Capital and Resource-Based View frameworks. By embedding sustainability principles into HRM and mobilising intellectual capital across human, structural, and relational dimensions, the study demonstrates how organisational rent can be generated through socially sustainable practices
miRNome analysis using real-time PCR
No full textMicroRNAs (miRNAs) are short RNA molecules that regulate gene expression in eukaryotic organisms, thus influencing physiological mechanisms such as development, cell proliferation, cell death, and cell differentiation. The importance of the gene regulatory system operated by miRNAs is emerging as a central topic in the setting of several diseases included infectious disease and cancer. The different techniques used for the study of the entire "miRNome" give the opportunity to go better inside these novel mechanisms of gene expression regulation. In the following method we describe a protocol based on quantitative real-time PCR (qRT-PCR) with SYBR(®) green technology, to specifically analyze the expression levels of only those miRNAs that target genes involved in CTLs biogenesis and functions. Through an in silico approach, we designed a custom microRNA qPCR panel focused on those miRNAs relevant in regulation of CTLs-specific pathways. The panel we created was customized by EXIQON, since this company proposed a method based on the use of LNA enhanced primers, which guarantee increased affinity and specificity for each microRNA. The advantage of this protocol with respect to a whole miRNome analysis consists in the possibility to evidence weaker signals that otherwise would be secreted and remove the noise itself generated by other miRNAs not directly involved in the regulation of CTLs-specific pathways. This panel can be applicable in the study of CTLs behavior in pathological conditions such as infectious disease and cancer or can be used to characterize changes in patients' immune responsiveness after therapeutic intervention in order to understand the molecular mechanisms underlying these effects
The microarray-based approach for the analysis of the transcriptome.
No full textMicroarrays play an important role in the study of the transcriptome in a variety of conditions and species. This is documented by their widespread use over the last decade in areas such as cancer, immunology, neurological disorders, renal diseases, and many others, directed towards the new frontiers of personalized medicine and drug discovery. The following method covers a specific application of microarrays in the field of immunology, focusing on the study of antigen-induced T cell differentiation in response to viral or bacterial infection, and in the context of cancer. This protocol allows, through an "Omics" strategy, the study of the transcriptome of CTLs, concentrating only on the expression profiles of those genes more likely to be involved in CTL action. Since the biological question, in this case, is very specific, the advantage of this protocol with respect to a more traditional whole transcriptome microarray experiment is to remove the noise coming from all the genes not directly involved in the CTLs-specific pathways, highlighting weaker signals that otherwise would be hidden by the noise itself. To address this issue we have accurately selected all the CTLs-specific pathways, extracted all the genes belonging to them, and designed a CTL-specific microarray, based on all known validated transcripts deriving from these genes. This microarray has been built for the Agilent Technologies microarray platform, the only one that, to our knowledge, at present allows autonomously designing a completely customizable microarray. We used it in the context of renal cell carcinoma (RCC), but surely it will find several more applications in many other cancers and in the context of viral and bacterial infection
Exploring drivers and factors of benefit impact reports quality: Retracing a stakeholder theory approach
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