1,721,033 research outputs found
Casein phosphopeptides : from milk to nutraceutical
Full text linkMilk and dairy products are known sources of bioavailable calcium for its association with casein, whose proteolysis produces caseinphosphopeptides (CPPs). CPPs are phosphorylated peptides able to bind and solubilise calcium. In human intestinal tumor cells differentiated in vitro toward an enterocityc phenotype, they also induce a calcium uptake. Moreover, in human in vitro osteoblasts, CPPs favour the mineralization of the extracellular matrix. CPPs can differently affect proliferation and apoptosis in differentiated and /or tumor intestinal cells. Due to all these properties, CPPs may be considered as potential nutraceutical/functional food
INTERACTION OF CASEIN PHOSPHOPEPTIDES WITH CHANNELS INVOLVED IN CALCIUM ABSORPTION AND MODULATION OF PROLIFERATION RATE AND APOPTOSIS OF HUMAN INTESTINAL CELL LINES
Full text linkRecent studies have evidenced that dietary calcium is able to exert a chemoprotective role on normal differentiated intestinal cells, while it behaves as a carcinogenesis promoter on aberrant colonocytes and adenomatous crypts. These different functions can be achieved through the modulation of proliferation and/or differentiation processes, triggered by the increase of the calcium ion concentrations in the intestinal lumen after a meal. Milk represents the major source of calcium in the diet, due to the high availability of the mineral bound to casein and casein phosphopeptides (CPPs). CPPs, derived by in vitro or in vivo casein hydrolysis, are able to bind calcium, blocking the mineral precipitation in the presence of phosphate and /or sulphate salts and to induce a calcium uptake in human intestinal tumor cell lines HT-29 and Caco2 differentiated in vitro toward an enterocityc phenotype. Thus the hypothesis that CPPs could differently affect proliferation and apoptosis in undifferentiated and differentiated HT-29 and Caco2 cells through their binding with calcium ions was here investigated.
Results showed that in HT-29 cells CPPs protect differentiated cells from calcium overload toxicity, prevent their apoptosis, favoring proliferation, while in undifferentiated, tumor like, cells they induce apoptosis. The mechanism by which CPPs act in HT-29 cells is mainly the modulation of the voltage operated L-type calcium channels, known to activate calcium entry into the cells under depolarization, a situation occurring after a meal, and to exert a mitogenic effect. The L-type calcium channels have been now recognized to represent one of the two transcellular calcium absorption ways, characterized by the location in the distal ileum and the independence of vitamin D control. In Caco2 cells, CPPs did not significantly affect proliferation, while increase apoptosis in undifferentiated, tumor like, cells. The mechanism by which CPPs act in Caco2 cells is mainly through the TRPV6 channel, known as the main epithelial channel responsible for the transcellular calcium absorption at duodenum level, subject to vitamin D control and with a saturation kinetic for calcium.
Taken together these results demonstrate the ability for CPPs, to modulate the two principal transcellular calcium absorption mechanisms. Moreover, through the binding with calcium ions and the stimulated ingression of this mineral in intestinal cells, CPPs can directly modulate the biological activity strictly related to the expression of a normal or cancer phenotype, thus opening the way for a use of CPPs as nutraceutical/functional food
Mediterranean diet: functional foods and physical activity, benefits for human health
No full textThe Mediterranean diet is a well recognized life and food habits having relevantassociation with a reduced mortality caused by diseases such as cardiovascular disease,obesity, diabetes, cancer and neurodegenerative disorders. The importance of a healthybalanced diet lies on the fact that benefits come from the presence and the interaction ofalmost all the nutrients with which it is composed. It is a matter of fact that singlenutrients can behave differently from what it is observed when they are all mixedtogether with interactive possibility. Under this perspective, the Mediterranean diet isboth composed by a great number of single functional food and, as a whole, it is a resultof a balance between the single nutrient properties, as evidenced by its great capacity toprevent all the chronic degenerative disorders above mentioned. Among the functionalfood present in the Mediterranean diet are cereals, legumes, fruit and vegetables, nuts,olive oil as the prevalent fats for dressing, red wine in moderate quantity and consumed atmeals, fish and poultry as the main source of protein and polyunsaturated/saturated fats,modest quantity of dairy products, spices. Since the Mediterranean diet is a dietarypattern common to more than one country in the Mediterranean basin, some differencescan be found between the food consumed by the populations. The health benefits comingfrom the food of the Mediterranean diet resides on the presence of bioactive compoundssuch as polyphenols, carotenoids, phytosterols, fibers, monounsaturated andpolyunsaturated fatty acids, displaying antioxidant activity, protection from cancer andhypertension, improvement of the immune response. Due to the presence of more thanone functional food groups in the same dietary pattern, sometimes in the same meal,diverse species of polyphenols as well as of phytosterols, fibers and fatty acids can becombined and activated. Next to the positive properties derived from the food, the physical activity also account for an important aspect of this life habits. In fact, sincelifestyle modification programs provide a method to change eating and activity habits,any diet intervention becomes more valid with a regular daily physical activity.The last element characterizing the Mediterranean diet is the perception of a meal asa moment to spend with other people and of food as a positive link. For all these complexand heterogeneous aspects, the Mediterranean diet has recently been named as"intangible cultural heritage by UNESCO"
La Probabilità nel Progetto MathOnline
No full textGli autori hanno collaborato a definire e implementare tutte le fasi della progettazione di un'unità didattica del progetto-ponte "MathOnline" offerto dal centro METID del Politecnico di Milano alla fruizione di studenti e docenti delle scuole superiori italiane
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
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