171 resultados para Dino De Laurentiis
Resumo:
Background: Oxidative stress has been implicated in the development of peritoneal damage. The aim of this study was to evaluate the effects of N-acetylcysteine (NAC) in a rat peritoneal infusion model. Methods: Eighteen male Wistar rats were divided in 3 groups: (i) control group; (ii) HDS group, receiving peritoneal dialysis solution (PDS); and (iii) HDS+NAC group, receiving PDS and oral NAC. Six weeks later they were evaluated for dialysate to plasma urea ratio (D/P), ratio of glucose concentration in peritoneal fluid (G1/G0), thiobarbituric acid reactive substances in plasma and urine and histology of peritoneal membrane. Results: The HDS+NAC group presented a lower increase in solute transport (D/P 0.51 +/- 0.1, and G1/GO 0.35 +/- 0.06) in comparison with the HDS group (D/P 0.67 +/- 0.1; p=0.03, and G1/G0 0.27 +/- 0.07; p=0.01). The HDS+NAC group showed lower thiobarbituric acid reactive substance concentrations compared with the HDS group. In the treated group, the peritoneal membrane presented lower thickness. Conclusions: Functional and histological peritoneal changes were significantly reduced by the treatment with NAC.
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OBJETIVO: Estudar a viabilidade de aponeurose heteróloga para fechar parede abdominal de coelhos, com ênfase no processo de rejeição. MÉTODOS: Este projeto foi aprovado pelo Comitê de Cuidados Animais da Faculdade de Ciências Médicas da Santa Casa de São Paulo e realizado na Unidade Técnica e Cirurgia Experimental. Quatro coelhas vermelhas trocaram aponeurose da parede abdominal com outros quatro animais machos brancos. Em dois coelhos, foi retirada e substituída a aponeurose como controle do processo cicatricial. Eles foram avaliados 1 vez por dia e sacrificados após 7 dias. Foi realizada a imunoistoquímica com CD20 e CD79. RESULTADOS: Os animais não tiveram celulite, abscesso, hematoma, deiscência da ferida ou hérnia. O local do enxerto mostrou hiperemia intensa. A análise histológica mostrou um processo inflamatório, com a presença de miofibroblastos em amadurecimento e colágeno, que variou de incipiente a moderado. O número de vasos estava reduzido e as células inflamatórias foram, em sua maioria, células plasmáticas e macrófagos. Não havia sinais morfológicos da rejeição aguda com a agressão do endotélio vascular. O músculo adjacente mostrou sinais de degeneração, com reação inflamatória dos núcleos e condensação do citoplasma. A análise imunoistoquímica (CD20 e CD79) mostrou que o processo inflamatório não foi mediado por linfócitos. O teste não paramétrico de Mann-Whitney mostrou que não se pode rejeitar a hipótese de igualdade (p>0,05). CONCLUSÃO: Não houve complicações pós-operatórias (fístulas, deiscência etc.) e a análise histológica revelou processo inflamatório inespecífico. A análise imunoistoquímica mostrou que o processo inflamatório não foi em razão de uma possível rejeição.
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Polymer blends constitute a valuable way to produce relatively low cost new materials. A still open question concerns the miscibility of polyethylene blends. Deviations from the log-additivity rule of the newtonian viscosity are often taken as a signature of immiscibility of the two components. The aim of this thesis is to characterize the rheological behavior in shear and elongation of five series of LLDPE/LDPE blends whose parent polymers have been chosen with different viscosity and SCB content and length. Synergistic effects have been measured for both zero shear viscosity and melt strength. Both SCB length and viscosity ratio between the components have been found to be key parameters for the miscibility of the pure polymers. In particular the miscibility increases with increasing SCB length and with decreasing the LDPE molecular weight and viscosity. This rheological behavior has significant effects on the processability window of these blends when the uni or biaxial elongational flows are involved. The film blowing is one of the processes for which the synergistic effects above mentioned can be crucial. Small scale experiments of film blowing performed for one of the series of blends has demonstrated that the positive deviation of the melt strength enlarges the processability window. In particular, the bubble stability was found to improve or disappear when the melt strength of the samples increased. The blending of LDPE and LLDPE can even reduce undesired melt flow instability phenomena widening, as a consequence, the processability window in extrusion. One of the series of blends has been characterized by means of capillary rheometry in order to allow a careful morphological analysis of the surface of the extruded polymer jets by means of Scanning Electron Microscopy (SEM) with the aim to detect the very early stages of the small scale melt instabilty at low shear rates (sharksin) and to follow its subsequent evolution as long as the shear rate was increased. With this experimental procedure it was possible to evaluate the shear rate ranges corresponding to different flow regions: smooth extrudate surface (absence of instability), sharkskin (small scale instability produced at the capillary exit), stick-slip transition (instability involving the whole capillary wall) and gross melt fracture (i.e. a large scale "upstream" instability originating from the entrance region of the capillary). A quantitative map was finally worked out using which an assessment of the flow type for a given shear rate and blend composition can be predicted.
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I problemi ambientali legati alla tossicità delle OMW e l’impossibilità del loro utilizzo diretto come acque di irrigazione, a causa dell’elevato contenuto di composti fenolici, spingono verso lo sviluppo di un processo di separazione che permetta la decontaminazione e valorizzazione delle acque di scarto e il recupero dei composti fenolici ad alto valore aggiunto. Lo scopo del lavoro è stato quello di studiare la fattibilità di un processo in continuo per il recupero dei composti fenolici contenuti nelle acque di vegetazione di due differenti oleifici, mediante adsorbimento in fase solida su una resina polimerica.
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Neurodevelopment of preterm children has become an outcome of major interest since the improvement in survival due to advances in neonatal care. Many studies focused on the relationships among prenatal characteristics and neurodevelopmental outcome in order to identify the higher risk preterms’ subgroups. The aim of this study is to analyze and put in relation growth and development trajectories to investigate their association. 346 children born at the S.Orsola Hospital in Bologna from 01/01/2005 to 30/06/2011 with a birth weight of <1500 grams were followed up in a longitudinal study at different intervals from 3 to 24 months of corrected age. During follow-up visits, preterms’ main biometrical characteristics were measured and the Griffiths Mental Development Scale was administered to assess neurodevelopment. Latent Curve Models were developed to estimate the trajectories of length and of neurodevelopment, both separately and combined in a single model, and to assess the influence of clinical and socio-economic variables. Neurodevelopment trajectory was stepwise declining over time and length trajectory showed a steep increase until 12 months and was flat afterwards. Higher initial values of length were correlated with higher initial values of neurodevelopment and predicted a more declining neurodevelopment. SGA preterms and those from families with higher status had a less declining neurodevelopment slope, while being born from a migrant mother proved negative on neurodevelopment through the mediating effect of a being taller at 3 months. A longer stay in NICU used as a proxy of preterms’ morbidity) was predictive of lower initial neurodevelopment levels. At 24 months, neurodevelopment is more similar among preterms and is more accurately evaluated. The association among preterms’ neurodevelopment and physiological growth may provide further insights on the determinants of preterms’ outcomes. Sound statistical methods, exploiting all the information collected in a longitudinal study, may be more appropriate to the analysis.
Resumo:
Adjuvant therapy has improved the survival of women with early breast cancer (BC). Meta-analyses suggest that anthracycline-based regimens reduced the annual BC death rate by 40% in women below the age of 50 and 20% in older women. Novel agents designed to modulate abnormal growth factor signaling in and around the BC cell further increase patients' chances of survival. However, both conventional chemotherapeutic agents as well as some of the novel signaling inhibitors can induce important cardiovascular side-effects, potentially attenuating the progress made in recent years. The mechanism of cancer drug-induced cardiovascular complications varies greatly with some compounds inducing irreversible myocardial cell damage, while others lead to temporary cell dysfunction. The challenge of the future will be to prospectively discriminate between irreversible damage which can lead to progressive cardiovascular disease and reversible cardiovascular dysfunctions without further prognostic implications. Since adjuvant therapy for BC is potentially curative, emphasis must be placed on finding treatments combining maximum efficacy with the minimum of long-term side-effects in order to achieve survival with preserved quality of life.
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Transforming growth factor-β (TGFβ) plays an important role in breast cancer metastasis. Here phosphoinositide 3-kinase (PI3K) signalling was found to play an essential role in the enhanced migration capability of fibroblastoid cells (FibRas) derived from normal mammary epithelial cells (EpH4) by transduction of oncogenic Ras (EpRas) and TGFβ1. While expression of the PI3K isoform p110δ was down-regulated in FibRas cells, there was an increase in the expression of p110α and p110β in the fibroblastoid cells. The PI3K isoform p110β was found to specifically contribute to cell migration in FibRas cells, while p110α contributed to the response in EpH4, EpRas and FibRas cells. Akt, a downstream targets of PI3K signalling, had an inhibitory role in the migration of transformed breast cancer cells, while Rac, Cdc42 and the ribosomal protein S6 kinase (S6K) were necessary for the response. Together our data reveal a novel specific function of the PI3K isoform p110β in the migration of cells transformed by oncogenic H-Ras and TGF-β1.
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Eight human catalytic phosphoinositide 3-kinase (PI3K) isoforms exist which are subdivided into three classes. While class I isoforms have been well-studied in cancer, little is known about the functions of class II PI3Ks.
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Methods are described for working with Nosema apis and Nosema ceranae in the field and in the laboratory. For fieldwork, different sampling methods are described to determine colony level infections at a given point in time, but also for following the temporal infection dynamics. Suggestions are made for how to standardise field trials for evaluating treatments and disease impact. The laboratory methods described include different means for determining colony level and individual bee infection levels and methods for species determination, including light microscopy, electron microscopy, and molecular methods (PCR). Suggestions are made for how to standardise cage trials, and different inoculation methods for infecting bees are described, including control methods for spore viability. A cell culture system for in vitro rearing of Nosema spp. is described. Finally, how to conduct different types of experiments are described, including infectious dose, dose effects, course of infection and longevity tests
Resumo:
Adult honey bees are maintained in vitro in laboratory cages for a variety of purposes. For example, researchers may wish to perform experiments on honey bees caged individually or in groups to study aspects of parasitology, toxicology, or physiology under highly controlled conditions, or they may cage whole frames to obtain newly emerged workers of known age cohorts. Regardless of purpose, researchers must manage a number of variables, ranging from selection of study subjects (e.g. honey bee subspecies) to experimental environment (e.g. temperature and relative humidity). Although decisions made by researchers may not necessarily jeopardize the scientific rigour of an experiment, they may profoundly affect results, and may make comparisons with similar, but independent, studies difficult. Focusing primarily on workers, we provide recommendations for maintaining adults under in vitro laboratory conditions, whilst acknowledging gaps in our understanding that require further attention. We specifically describe how to properly obtain honey bees, and how to choose appropriate cages, incubator conditions, and food to obtain biologically relevant and comparable experimental results. Additionally, we provide broad recommendations for experimental design and statistical analyses of data that arises from experiments using caged honey bees. The ultimate goal of this, and of all COLOSS BEEBOOK papers, is not to stifle science with restrictions, but rather to provide researchers with the appropriate tools to generate comparable data that will build upon our current understanding of honey bees.