1,720,998 research outputs found
Effects of Oleuropein on colon cancer progression in vitro. A preliminary report
Full text linkIntroduction. Accumulating evidence highlights that Oleuropein (OLE), one of the main bioactive phenolic compound present in olives, olive oil and olive leaves, appears to exert chemo-preventive effects against several human malignancies including gastrointestinal tumors. As the cellular mechanisms underlying this phenomenon are still not fully elucidated, we have undertaken some in vitro studies to examine the effects of OLE on the growth, adhesion and invasion of HTC116 and SW480 human colon cancer cells and the influence of this molecule on the production of certain proteins that appear to be relevant to cancer progression namely, matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) and transforming growth factor-β (TGF-β)
Methods. The effects of OLE on HTC116 and SW480 colon cancer cells growth, adhesion and invasion were evaluated by i) the colorimetric MTT assay, ii) the fibronectin coated multi-well assay and iii) the Matrigel transwell invasion assay, respectively. The influence of OLE on the rate of MMP-2, MMP-9 and TGF-β secretion by tumor cells during adhesion and invasion were determined by enzyme-linked immunosorbent assay.
Results.
1)Exposure of human HCT116 and SW480 cancer cells for 24 or 72h to different concentrations of OLE (10-500 μM) resulted in a dose- and time-dependent inhibition of cell proliferation. The calculated IC50 values were 323.1μM and 186.8μM at 24h and 72h respectively for HCT116 tumor cells and 317.6μM at 24h and 226.8 μM at 72h for SW480 tumor cells.
2) The adhesion of HTC116 tumor cells exposed to non-cytotoxic concentrations of OLE (50-250 μM) up to 4h was reduced by 30% as compared to untreated cells while, a 72h continuous exposure to OLE (10-100 μM) decreased HTC116 cell invasion by 40%. This molecule showed to inhibit also SW480 tumor cell adhesion (-25%) but only at the highest drug concentration (250 μM) while, its effects on SW480 invasion were negligible.
3) The secretion of MMP-2, MMP-9 and TGF-β by OLE-treated HCT116 cells during adhesion experiments was reduced (-39%,-19%,-48% respectively) as compared to unexposed cells while, in invasion experiments, the extracellular release of MMP-2 and MMP-9 resulted increased at 24h (+41% and +23%) and then decreased (~ -25%) after 72h. However, TGF-β secretion was not significantly influenced by drug treatments. Finally, in invasion experiments, MMP-9 and TGF-β secretion by OLE-treated SW480 cells resulted impaired (-32% and-74% respectively) while, MMP-2 levels were only slightly affected ( -10%)
Conclusions. These data indicate that OLE might exert its chemo-preventive effects by interfering with some key steps of cancer progression, such as tumor cell proliferation, adhesion and invasion and by modulating the extracellular secretion of proteins that may foster these processes. Further studies to better assess the specific molecular mechanisms underlying these phenomena are warranted by these preliminary observations
Bioactive effects of citrus flavonoids and role in the prevention of atherosclerosis and cancer
Full text linkCitrus fruits are the main fruits of the Mediterranean diet and
have been long recognized for their beneficial effects on human
health. Observational studies have shown a significant association
between dietary flavonoid intake and reduced risk of cardiovascular
and malignant diseases. The beneficial effects of citrus fruits
on human health appear to be due to their high content in vitamins,
minerals and fibers. In particular, the antioxidant and anti-inflammatory
activities have been indicated as some of the mechanisms
through which citrus fruits may thwart the development of chronic
degenerative diseases such as atherosclerosis and cancer. This
review would critically examine the results from numerous experimental
and clinical studies carried out in order assess the contribute
of citrus flavonoids to the prevention of chronic pathological
conditions including atherosclerosis and cancer
Nutrition, obesity and hormones
Full text linkObesity is a chronic pathological condition with a multifactorial aetiology, characterised by an excessive body fat accumulation with multiple organ-specific consequences. Emerging evidence highlights that obesity appears to be associated with multiple alterations in the endocrine system. However, the mechanisms underlying the interactions between obesity and this system remain still controversial. This review discusses the impact of obesity on various endocrine systems and, in particular, would provide a general overview on the biochemical changes that may occur in each of these axes in association with obesity
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
Childhhood obesity, insulin resistance and increased cardiovascular risk [Obesità infantile, insulino-resistenza ed aumentato rischio cardiovascolare]
No full textExcess fat is one of the major risk factors for insulin resistance predisposing to the development of cardiovascular diseases in western countries. We know that obese patients are strongly at risk of cardiovascular diseases, like myocardial infarction or stroke. These diseases are the most frequent cause of death in the adult population, representing a social and economic problem. Today there are not available and useful markers for screening and diagnosis of insulin resistance in young people. "Easy-to-detect" clinical markers must be found to identify young subjects at risk of cardiovascular diseases. Very interesting the relationship between wrist circumference, its bone composition and insulin resistance
The promoter region of the adiponectin gene is a determinant in modulating insulin sensitivity in childhood obesity
No full textWe investigated the association of the -11,3916>A, -11,3776>C +45T>G, and +2766>T adiponectin single-nucleotide polymorphisms (SNPs) and expected haplotypes with the insulin resistance (IR) state in overweight/obese children; by using the haplotype background analysis, we also assessed the effect of each SNP independently. GG genotype at the -11,391 locus was associated with higher fasting insulin levels and homeostasis model assessment-IR index and lower adiponectin levels compared with GA + AA genotypes (p = 0.01, 0.002, and 0.03, respectively). Those heterozygous and homozygous for G allele at the -11,377 locus showed higher fasting glucose (p = 0.001 for both), fasting insulin (p = 0.001 for both), homeostasis model assessment-IR index (p A, -11,377C>G, and +45T>G SNPs are associated with IR syndrome in overweight/obese children; they independently influence the investigated variables. The effect of +45T>G SNP seems to be marginal compared with the promoter SNPs. The GGT haplotype is associated with the highest degree of IR
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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