436 research outputs found

    Protein Stability, Folding and Misfolding in Human PGK1 Deficiency

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    Conformational diseases are often caused by mutations, altering protein folding and stability in vivo. We review here our recent work on the effects of mutations on the human phosphoglycerate kinase 1 (hPGK1), with a particular focus on thermodynamics and kinetics of protein folding and misfolding. Expression analyses and in vitro biophysical studies indicate that disease-causing mutations enhance protein aggregation propensity. We found a strong correlation among protein aggregation propensity, thermodynamic stability, cooperativity and dynamics. Comparison of folding and unfolding properties with previous reports in PGKs from other species suggests that hPGK1 is very sensitive to mutations leading to enhance protein aggregation through changes in protein folding cooperativity and the structure of the relevant denaturation transition state for aggregation. Overall, we provide a mechanistic framework for protein misfolding of hPGK1, which is insightful to develop new therapeutic strategies aimed to target native state stability and foldability in hPGK1 deficient patients.Grants P11-CTS-07187 (from Junta de Andalucia), CSD-2009-00088 and BIO-2012-34937 (from MINECO)Ramón y Cajal research contract from MINECO (RYC-2009-04147)Ministero dell’Istruzione, dell’Università e della Ricerca - “Fondo per le Agevolazioni alla Ricerca” (FAR

    Metal free graphene oxide (GO) nanosheets and pristine-single wall carbon nanotubes (p-SWCNTs) biocompatibility investigation: a comparative study in different human cell lines

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    The in vitro biocompatibility of Graphene Oxide (GO) nanosheets, which were obtained by the electrochemical exfoliation of graphite electrodes in an electrolytic bath containing salts, was compared with the pristine Single Wall Carbon Nanotubes (p-SWCNTs) under the same experimental conditions in different human cell lines. The cells were treated with different concentrations of GO and SWCNTs for up to 48 h. GO did not induce any significant morphological or functional modifications (demonstrating a high biocompatibility), while SWNCTs were toxic at any concentration used after a few hours of treatment. The cell viability or cytotoxicity were detected by the trypan blue assay and the lactate dehydrogenase LDH quantitative enzymatic test. The Confocal Laser Scanning Microscopy (CLSM) and transmission electron microscopy (TEM) analysis demonstrated the uptake and internalization of GO sheets into cells, which was localized mainly in the cytoplasm. Different results were observed in the same cell lines treated with p-SWCNTs. TEM and CLSM (Confocal Laser Scanning Microscopy) showed that the p-SWCNTs induced vacuolization in the cytoplasm, disruption of cellular architecture and damage to the nuclei. The most important result of this study is our finding of a higher GO biocompatibility compared to the p-SWCNTs in the same cell lines. This means that GO nanosheets, which are obtained by the electrochemical exfoliation of a graphite-based electrode (carried out in saline solutions or other physiological working media) could represent an eligible nanocarrier for drug delivery, gene transfection and molecular cell imaging tests

    granulocyte transfusions a critical reappraisal

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    Granulocyte transfusions (GTs) are seldom used as a life-saving therapy for neutropenic patients with severe infections. Despite compelling evidence of GT efficacy in retrospective and prospective case series, no study has been successful in demonstrating a definite advantage for recipients in controlled clinical trials. This review critically revises some aspects emerging from past experience that might have weakened the evidence of GT benefits. Some specific issues relevant to the efficacy of this therapeutic approach, such as primary infection, delivered doses and schedules, and immunologic effects of GTs, are discussed. Importantly, the awareness of biologic effects accompanying the transfusion of neutrophils might support their use at standardized doses and may definitely convey significant advantages to the recipient patients

    Clinical Aspects and Therapy of Sporadic Burkitt Lymphoma

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    Burkitt’s lymphoma is a highly aggressive mature B-cell neoplasm consisting of endemic, sporadic, and immunodeficiency-associated variants, sharing many morphologic and immunophenotypic features. It is characterized by a high proliferation rate and propensity for extranodal sites such as gastrointestinal tract and reproductive organs. Brief-duration, high-intensity chemotherapy regimens including aggressive central nervous system prophylaxis have had remarkable success in the treatment of this disease in the sporadic form, with very high complete remission rate and overall survival in adults. Although Burkitt’s lymphoma is extremely chemosensitive, biologically targeted therapies should be developed, because current treatment options are suboptimal for patients with poor prognostic features or with relapsed disease

    Gene-specific methylation profiles in BRCA-mutation positive and BRCA-mutation negative male breast cancers

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    Male breast cancer (MBC) is a rare disease. Due to its rarity, MBC research and clinical approach are mostly based upon data derived from female breast cancer (FBC). Increasing evidence indicate that on molecular level MBC may be an heterogeneous disease different from FBC. In order to investigate whether epigenetic signatures could define molecular subgroups of MBCs, we performed promoter methylation analysis of genes involved in signal transduction and hormone signalling in BRCA1/2 mutation-positive and -negative MBCs. We examined 69 MBCs, paired blood samples, and 15 normal tissues for promoter methylation of hTERT, ESR1, RASSF1, AR, MYC and WNT1 genes. MBCs showed higher gene promoter methylation levels compared to paired blood and normal breast samples. Significantly higher RASSF1 methylation levels were observed in association with BRCA1/2 mutations, HER2 expression and high tumor grade. Significantly higher AR methylation levels were observed in BRCA1/2 wild-type cases and higher WNT1 methylation levels in PR negative cases. Overall, our results indicate that alterations in gene methylation profiles are common in MBC and that methylation pattern of tumor-associated genes may allow for the identification of MBC molecular subgroups, that could have implications in clinical management of MBC patients

    Lo sport come progetto di vita

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    In rugby as in life you run towards a goal: our life as a whole tends toward a goal. This research is laborious and it requires struggle and diligence. The important thing is not to run alone. Sport has often been used as a life metaphor and actually, on the basis of a regulatory framework shown by Miur, it is possible to highlight the importance of physical activity at school from the point of view of integration and across the board perspective. Physical activities and sports support the proper physiological, morphological, emotional, cognitive and socio relational development of the individual aiming at the acquisition of adequate lifestyles and a fair competition respecting the mate. Educationalagencies are fundamental and cooperating one another they have to aim atdeveloping mutual learning creating meaning, a way of integration which requires a new communicability. The attention may be focused on a sport which has several meanings such as culture, friendship, collaboration, performance but mostly fair play: rugby. Rugby promoting plan can be a chance for every pupil, it’s not a well known sport which is easy to learn. It’s a newness, and as such, students like it. You can develop coordination and conditional abilities. Basing everything on contact it can’t do without some essential values including respect of the rule and of the enemy.Nel rugby, come nella vita, si corre verso la meta: tutta la nostra vita tende a una meta.Questa ricerca è faticosa, richiede lotta e impegno; l’importante è non correre da soli.Lo sport è stato spesso utilizzato come metafora della vita ed effettivamente, proprio sulla base di un quadro normativo presentato dal Miur, è possibile evidenziare l’importanza dell’attività motoria nella scuola in un’ottica di integrazione, interdisciplinarità e trasversalità. Le attività motorie e sportive favoriscono il corretto sviluppo fisiologico, morfologico, emotivo, cognitivo e socio-relazionale della persona muovendo l’acquisizione di corretti stili di vita ed una competizione sana nel rispetto del compagno.Fondamentale è l’azione delle agenzie educative, le quali, in collaborazione tra loro, dovrebbero mirare allo sviluppo di una cultura dell’apprendimento reciproco che produca significati, una cultura dell’integrazione che esige una nuova comunicabilità. L’attenzione può rivolgersi ad uno sport che è amicizia, cultura, collaborazione, spettacolo, ma soprattutto fair play: il rugby. Il progetto di promozione rugbystica può essere un’occasione per tutti gli alunni; è un gioco sportivo poco conosciuto che si apprende facilmente, è una novità e come tale piace agli alunni. Il rugby migliora lo sviluppo sia delle capacità coordinative che di quelle condizionali, basando tutto sul contatto, infine è uno sport che non può fare a meno di alcuni valori fondamentali tra cui il rispettodella regola e  dell’avversario*

    Carbon stock increases up to old growth forest along a secondary succession in Mediterranean island ecosystems

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    The occurrence of old-growth forests is quite limited in Mediterranean islands, which have been subject to particularly pronounced human impacts. Little is known about the carbon stocks of such peculiar ecosystems compared with different stages of secondary succession. We investigated the carbon variation in aboveground woody biomass, in litter and soil, and the nitrogen variation in litter and soil, in a 100 years long secondary succession in Mediterranean ecosystems. A vineyard, three stages of plant succession (high maquis, maquis-forest, and forest-maquis), and an old growth forest were compared. Soil samples at two soil depths (0–15 and 15–30 cm), and two litter types, relatively undecomposed and partly decomposed, were collected. Carbon stock in aboveground woody biomass increased from 6 Mg ha-1 in the vineyard to 105 Mg ha-1 in old growth forest. Along the secondary succession, soil carbon considerably increased from about 33 Mg ha-1 in the vineyard to about 69 Mg ha-1 in old growth forest. Soil nitrogen has more than doubled, ranging from 4.1 Mg ha-1 in the vineyard to 8.8 Mg ha-1 in old growth forest. Both soil parameters were found to be affected by successional stage and soil depth but not by their interaction. While the C/N ratio in the soil remained relatively constant during the succession, the C/N ratio of the litter strongly decreased, probably following the progressive increase in the holm oak contribution. While carbon content in litter decreased along the succession, nitrogen content slightly increased. Overall, carbon stock in aboveground woody biomass, litter and soil increased from about 48 Mg ha-1 in the vineyard to about 198 Mg ha-1 in old growth forest. The results of this study indicate that, even in Mediterranean environments, considerable amounts of carbon may be stored through secondary succession processes up to old growth forest

    Mycobacterium tuberculosis Phosphoribosylpyrophosphate Synthetase: Biochemical Features of a Crucial Enzyme for Mycobacterial Cell Wall Biosynthesis

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    The selection and soaring spread of Mycobacterium tuberculosis multidrug-resistant (MDR-TB) and extensively drug-resistant strains (XDR-TB) is a severe public health problem. Currently, there is an urgent need for new drugs for tuberculosis treatment, with novel mechanisms of action and, moreover, the necessity to identify new drug targets. Mycobacterial phosphoribosylpyrophosphate synthetase (MtbPRPPase) is a crucial enzyme involved in the biosynthesis of decaprenylphosphoryl-arabinose, an essential precursor for the mycobacterial cell wall biosynthesis. Moreover, phosphoribosylpyrophosphate, which is the product of the PRPPase catalyzed reaction, is the precursor for the biosynthesis of nucleotides and of some amino acids such as histidine and tryptophan. In this context, the elucidation of the molecular and functional features of MtbPRPPase is mandatory. MtbPRPPase was obtained as a recombinant form, purified to homogeneity and characterized. According to its hexameric form, substrate specificity and requirement of phosphate for activity, the enzyme proved to belong to the class I of PRPPases. Although the sulfate mimicked the phosphate, it was less effective and required higher concentrations for the enzyme activation. MtbPRPPase showed hyperbolic response to ribose 5-phosphate, but sigmoidal behaviour towards Mg-ATP. The enzyme resulted to be allosterically activated by Mg2+ or Mn2+ and inhibited by Ca2+ and Cu2+ but, differently from other characterized PRPPases, it showed a better affinity for the Mn2+ and Cu2+ ions, indicating a different cation binding site geometry. Moreover, the enzyme from M. tuberculosis was allosterically inhibited by ADP, but less sensitive to inhibition by GDP. The characterization of M. tuberculosis PRPPase provides the starting point for the development of inhibitors for antitubercular drug design

    Cibo, Salute, SostenibilitĂ 

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    The world is at present the protagonist in a scenario where food has more and more influence in our lives. Food education aims to raise awareness of choices in order to promote a relationship with food that is both pleasant at an individual level and sustainable on a general level, both correct froma nutritional point of view and respectful of the environment. This is the reason why our purpose is to try to offer a panorama on the theme “food-health-sustainability” in order to show the importance of being aware of the different factors that influence our lives, our choices and our future both as persons and as citizens. The first part of this contribution is the result of data analysis collectedthanks to an investigation carried out by the University of Urbino during Expo 2015; with the aid, for the whole contribution, of a scientific bibliographical research both meticulous and up-to-date. The second part of the contribution focuses on the safety and healthiness of food because the pedagogic challenge is the quality of life and, in particular, that of future generations. The third part, obesity and physical activity. We can achieve many goals if we do a gradual, correct and regular physical activity that should also be very carefully planned both at school and during our free time: we can be in good shape by eating healthy; we can know ourselves, other people, the environment; we can learn a lot of things with joy and easily because we learn the world through our bodies, especially children.Il mondo attuale è protagonista di uno scenario in cui l’alimentazione ha un ruolo sempre più influente sulla vita dell’uomo. L’educazione alimentare, infatti, ha lo scopo di favorire la consapevolezza delle scelte in vista di una relazione col cibo che sia piacevole sul piano individuale e sostenibile sul piano collettivo, corretta da un punto di vista nutrizionistico e rispettosa dell’ambiente. Per questo, il nostro obiettivo è quello di provare ad offrire una panoramica sul tema “cibo salute-sostenibilità” evidenziando l’importanza della conoscenza dei diversi fattori che incidono sulla nostra vita, sulle nostre scelte, sul nostro futuro di uomini e cittadini. Il contributo muove le proprie riflessioni a partiredall’analisi di dati raccolti durante un’indagine condotta presso l’Ateneo di Urbino nell’ambito delle iniziative sull’Expo 2015 nella prima parte. Aiutati, per tutto il contributo, da una ricerca bibliografica scientifica rigorosa e aggiornata, nella seconda, si ragiona sulla sicurezza e salubrità degli alimenti in quanto la sfida pedagogica è la qualità di vita ed in particolare monitorare quella delle futuregenerazioni. Terza parte, obesità e attività fisica sottolineando che con un corretto, graduale e costante esercizio fisico, sportivo a scuola e nel tempo libero si potranno raggiungere più obiettivi: essere in forma mangiando sano; conoscere meglio il sé, gli altri, l’ambiente; apprendere in forma ludica altri saperi perché tutto passa attraverso il corpo specie in età evolutiva
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