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Search Results: 1 - 10 of 4446 matches for " Paola Romagnani "
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Possible mechanisms of kidney repair
Paola Romagnani, Raghu Kalluri
Fibrogenesis & Tissue Repair , 2009, DOI: 10.1186/1755-1536-2-3
Abstract: Most epithelia need to constantly replace damaged or dead cells throughout life. The process of continual cell replacement is critical for the maintenance of adult tissues and is typically maintained through the presence of stem cells. Stem cells are functionally defined by their ability to self-renew and to differentiate into the cell lineages of their tissue of origin [1]. Once activated, epithelial stem cells can generate proliferating progeny, which are often referred to as transiently amplifying cells. In their normal environment, transiently amplifying cells will divide actively for a restricted period of time, expanding the cellular pool that will then differentiate along a particular cell lineage to make the tissue. The physiological replacement of cells varies substantially among different epithelia. The epithelium of the intestine completely self-renews within around 5 days. By contrast, interfollicular epidermis takes approximately 4 weeks to renew, whereas the lung epithelium can take as long as 6 months to be replaced. In addition some epithelia, such as hair follicles, present a cyclic mode of cell replacement [1]. Similarly, the mammary gland proceeds through cycles of growth and degeneration during and following pregnancy [1]. In addition, stem cells are critically involved in regeneration upon wounding. Unless the epithelial stem/progenitor cells are permanently damaged, most epithelia are able to repair their tissues following injury [1]; when epithelial stem cells are depleted, fibrotic responses occur [1].The understanding of kidney repair is still in its infancy despite the rapid advances made in recent years. The kidney is one of the few organs that undergo mesenchymal-epithelial transition during development [2]. Moreover, structures present in the adult kidney arise from reciprocal interactions between two discrete embryonic appendages, namely the ureteric bud (UB) and metanephric mesenchyme (MM) [2]. The adult kidney contains more than 24 ma
Giant Calcified Renal Artery Aneurysm: Traditional RX versus Three-Dimensional Computed Tomography  [PDF]
Mauro Gacci, Omar Saleh, Annalisa Mantella, Leonidas Azas, Paola Romagnani, Andrea Minervini, Sergio Serni, Marco Carini
Advances in Computed Tomography (ACT) , 2013, DOI: 10.4236/act.2013.21004
Abstract: A 65-year-old woman with no history of previous flank trauma, renal stone or upper urinary tract infections, presented for flank pain and left hydro-uretero-nephrosis seven days after hysterectomy. Percutaneous pielography revealed narowing of the distal ureter, without endoureteral mass. The plain abdomen film incidentally showed a 3-cm calcified ring on the left renal shadow, who resulted external to the collecting system at pielography. A 3-dimensional-CT scan with angiographic reconstruction revealed a 3-cm calcified renal artery aneurysm. The vascular surgeon suggested a watchful waiting. The patient underwent ureteral reimplantation with ureteral stenting, allowing a complete recovery of iatrogenic stenosis two months postoperatively.
Human Th17 cells
Sergio Romagnani
Arthritis Research & Therapy , 2008, DOI: 10.1186/ar2392
Abstract: The adaptive effector CD4+ T helper (Th)-mediated immune response is highly heterogeneous, based on the development of distinct subsets that are characterized by various profiles of cytokine production. Initially, two polarized forms of Th effectors, namely type 1 (Th1) and type 2 (Th2), were identified in both mice and humans [1,2]. Th1 cells produce interferon (IFN)-γ and their primary role is to protect against intracellular microbes; in contrast, Th2 cells produce IL-4, IL-5, IL-9 and IL-13 and are involved in protection against gastrointestinal nematodes, but they are also responsible for allergic disorders [3,4].Th1 and Th2 cells develop via activation of various transcription factors, the most important being signal transducer and activator of transcription (STAT)-4 and T box expressed in T cells (T-bet) for Th1 cells, and STAT-6 and GATA-binding protein (GATA)-3 for Th2 cells [5]. T-bet binds the promoter of IFN-γ whereas GATA-3 drives epigenetic changes in the Th2 cytokine cluster (IL-4, IL-5 and IL-13), thus giving rise to the development of Th1 and Th2 cells, respectively [6]. The mechanisms responsible for the polarization of the na?ve Th cells toward the Th1 or Th2 profile of cytokine production have not yet been completely clarified. However, early production of IFN-γ, IFN-α, or IL-12 by cells of the innate immune system drives Th1 differentiation, whereas early production of IL-4, in the absence of IL-12, drives Th2 differentiation [3,4]. Natural killer cells are the major source of IFN-γ, whereas plasmocytoid dendritic cells (DCs) are the major source of IFN-α [6]. The most powerful Th1-polarizing cytokine is IL-12 [7], which is produced by myeloid DCs after triggering of many of their Toll-like receptors by pathogen products. However, the expression by DCs of various ligands for the Notch receptors present on the na?ve Th cells appears also to be involved in the differentiation process. The prevalent expression on DCs of Jagged favours Th2 polarizat
Heterogeneity of human effector CD4+ T cells
Francesco Annunziato, Sergio Romagnani
Arthritis Research & Therapy , 2009, DOI: 10.1186/ar2843
Abstract: CD4+ T-helper (Th) lymphocytes represent a heterogeneous population of cells that play an essential role in adaptive immunity. These cells include effector cells, which are devoted to protection against pathogens, and regulatory T cells (Tregs), which protect against effector responses to autoantigens and also against responses to exogenous antigens when they may become dangerous for the host. The term Th derived from the observation that these cells were critical for helping B cells to produce antibodies in the primary response (humoral immunity). On the other hand, CD4+ T cells were also found to be responsible for the so-called cell-mediated immunity, or delayed-type hypersensitivity, which was characterized by the ability of these cells to induce inflammatory reactions mainly characterized by the activation of macrophages. The prototypic cell-mediated immune response was considered to be the skin papular reaction induced by intradermal injection of tuberculin or purified protein derivative (PPD) in animals infected with tubercular bacilli or in humans naturally infected by Mycobacterium tuberculosis or vaccinated with Bacillus Calmette-Guérin (BCG).The first demonstration of the existence of at least two different populations of CD4+ effector T cells was given in 1972 by Parish and Liew [1]. Injection of multiple doses of flagellin in Wistar rats allowed them to demonstrate that suppression of delayed-type hypersensitivity was observed when enhancement of antibody response occurred, suggesting an inverse relationship between humoral and cell-mediated immune response. In 1986 Mosmann and his coworkers showed that the functional heterogeneity of murine CD4+ T cells was due to their different profile of cytokine production [2], a finding that was also confirmed in humans [3,4]. Murine and human CD4+ T cells were categorized into two main subsets, which were defined as Th type 1 (Th1) or Th type 2 (Th2) [2-4].The reason for the heterogeneity of effector CD4+ Th cell
Signatures of Human NK Cell Development and Terminal Differentiation
Merlin Luetke-Eversloh,Chiara Romagnani
Frontiers in Immunology , 2013, DOI: 10.3389/fimmu.2013.00499
Abstract: Natural killer (NK) cells are part of the innate lymphoid cell (ILC) family and represent the main cytotoxic population. NK cells develop from bone marrow common lymphoid progenitors and undergo terminal differentiation in the periphery, where they finally gain their cytotoxic competence as well as the ability to produce IFN-γ in response to engagement of activating receptors. This process has been at least partially elucidated and several markers have been identified to discriminate different NK cell stages and other ILC populations. NK cell terminal differentiation is not only associated with progressive phenotypic changes but also with defined effector signatures. In this essay, we will describe the phenotypic and functional characteristics of the main stages of NK cell development and terminal differentiation and discuss them in light of recent discoveries of novel ILC populations.
The Employment of Young Graduates in the Period 2000-2010: A Comparison between Six European Countries  [PDF]
Paola Potestio
Modern Economy (ME) , 2011, DOI: 10.4236/me.2011.25099
Abstract: The paper aims to assess the relative importance of participation and unemployment and the interaction between them in affecting the evolution of employment rates of young graduates in selected European countries. The Taylor formula is used to read the behaviour of employment rates in terms of movements in activity and unemployment rates. Using this analytical procedure, the comparison between the selected countries underscores two aspects in particular: the progressive isolation of Italy, due to the poor results of the reform of the higher education system at the end of the 1990s, and the widespread progress within the female segments. On a more general plane, the heterogeneity of European labour markets for young graduates assumes new characteristics in the decade but—it is argued—it remains significant. The relative importance of participation and unemployment, the impact of the reforms of the higher education system, the reaction to the crisis of the late 2000s, and the gender aspects sharply differentiate the evolution of young graduate employment in the individual countries.
Factores de crecimiento y regeneración renal
Flaquer,M.; Romagnani,P.; Cruzado,J.M.;
Nefrología (Madrid) , 2010,
Abstract: cell replenishment is critical for adult tissue repair after damage. in some organs this process is facilitated by stem cells. in contrast to the liver, the kidney has limited capacity for regeneration. nevertheless, there are several recent studies suggesting the presence of stem cells in the adult kidney. stem cell renal niches have been identified in the renal papillae in animals as well as in the urinary pole of the bowman capsule in humans (cd24+cd133+ stem cells). although these cells may contribute to organ regeneration, how these cells exert this effect and their role after kidney damage is not known. nevertheless, renal stem cells may be therapeutic targets for treatment of renal diseases. on the other hand, bone marrow derived stem cells may also contribute in renal repair, particularly mesenchymal stem cells. however, the mechanism for producing such effect has not been elucidated. some studies suggest there is cell fusion between bone marrow and resident tubular cells; others suggest bone marrow cells are able to differentiate in resident cells, while some authors propose bone marrow cells facilitate organ regeneration by a paracrine action; that is by secreting growth factors as hepatocyte growth factor 1. all these secreted molecules would provide a regenerative milieu able to constrain renal damage and to amplify stem cells migration to the damaged organ.
High Pre-Transplant Serum Levels of CXCL10 Predict Early Renal Allograft Failure
E. Bertoni,P. Romagnani,M. Rotondi,A. Rosati
Transplantationsmedizin , 2003,
Abstract: Background: The chemokine CXCL10 is a potent chemoattractant for activated lymphocytes and dendritic cells and mediates vascular injury by inducing intimal hyperplasia and inhibition of endothelial cell growth. Neutralisation of CXCL10 prolongs allograft survival and transplant knock-out models have shown that this chemokine is required for the initiation and development of graft failure due to both acute and chronic rejection. In the present study, we investigated whether pre-transplant CXCL10 serum levels may predict the recipient risk of graft rejection and transplant failure. Methods: Pre-transplant sera of 299 cadaver kidney graft recipients were tested retrospectively for serum CXCL10 levels by a quantitative sandwich immunoassay.Results: Kidney graft recipients with normally functioning grafts showed higher pre-transplant CXCL10 serum levels than healthy controls, but significantly lower than patients who experienced graft failure (133.47± 119.6 vs. 182.8± 155.01 pg/ml; p<0.05). After the assignment of all patients to four groups at 25°, 50° and 75° centiles according to serum CXCL10 levels, the censored survival rates of grafts were 97.3%, 94%, 93.3%, 85.3% at 1-year. Accordingly, patients with the highest pre-transplant serum CXCL10 levels (75°-100°) centiles showed an increased frequency and severity of rejection episodes in the first month after transplantation. Conclusions: The results of this study show that high pre-transplant serum CXCL10 levels represent an important predictive risk factor for the development of rejection and transplant failure, thus suggesting that measurement of pre-transplant serum CXCL10 levels might represent a clinically useful marker for the transplant outcome.
An Integrated Statistical Model to Measure Academic Teaching Quality  [PDF]
Paola Cerchiello, Paolo Giudici
Open Journal of Statistics (OJS) , 2012, DOI: 10.4236/ojs.2012.25063
Abstract: The aim of this paper is to present a new proposal for the classification of Academic institutions in terms of quality of teaching. Our methodological proposal borrows concepts from operational risk, such as scorecard models, employed to assess University performances, on the basis of both the perceived and the actual quality. We propose to summarize opinion data using new non parametric indexes able to exploit efficiently the ordinal nature of the analysed variables and to integrate different sources of data. In particular we show how web survey methods can improve the quality and robustness of collected data, especially when integrated with students career data. Empirical evidence is given on the basis of real data from the University of Pavia.
Dirichlet Compound Multinomials Statistical Models  [PDF]
Paola Cerchiello, Paolo Giudici
Applied Mathematics (AM) , 2012, DOI: 10.4236/am.2012.312A288
Abstract:

This contribution deals with a generative approach for the analysis of textual data. Instead of creating heuristic rules forthe representation of documents and word counts, we employ a distribution able to model words along texts considering different topics. In this regard, following Minka proposal (2003), we implement a Dirichlet Compound Multinomial (DCM) distribution, then we propose an extension called sbDCM that takes explicitly into account the different latent topics that compound the document. We follow two alternative approaches: on one hand the topics can be unknown, thus to be estimated on the basis of the data, on the other hand topics are determined in advance on the basis of a predefined ontological schema. The two possible approaches are assessed on the basis of real data.

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