196,251 research outputs found
A mutational analysis of the 8-17 deoxyribozyme core
The 8-17 deoxyribozyme is a small RNA-cleaving DNA enzyme of significant applicative interest. We measured the kinetics of over 60 variants of 8-17, mutated within the "core" region. The data were analyzed according to a conceptual framework in which deleterious substitutions can either decrease the stability of the reaction's transition state, or favor unreactive ground-state conformations. In agreement with earlier in vitro evolution studies, the most severe functional effects were observed upon mutating four conserved residues, whose role was further explored by replacing them with non-standard nucleotides. Removal or modification of individual functional groups on the A6 and G7 bases suggested that these residues are involved in a close-contact interaction and form a network of functionally important hydrogen bonds. Mutagenesis of residues C13 and G14 was less revealing, but argued strongly against a role of C13 as a general acid/base catalyst. The use of non-standard nucleotides also led to the identification of one deoxyribozyme variant that, under some ionic conditions, is substantially more active than the wild-type construct. Finally, the effects of mutations in the intramolecular "core stem" correlated only in part with changes in helical stability, suggesting that a stable stem is required but not sufficient for optimal activity
TheMediterranean Diet and reduced cardiovascular disease: The Mediterranean diet (MD) may reduce cardiovascular disease (CVD) and mortality, but who actually benefits from its benefits?
Epidemiology of breast cancer, a paradigm of the “common soil” hypothesis
Breast cancer is the leading cause of death in women aged 20–50 years, with some geographical difference. The yearly incidence of the disease is increasing while the related mortality is steadily decreasing. Breast cancer is associated not only with specific hormones or factors related with reproduction, but mostly to more general environmental factors, linked to socioeconomic conditions and lifestyles (smoking, stress, physical exercise and particularly dietary habits). The latter, indeed, are risk factors or conditions common to hormone-dependent tumors and other chronic degenerative disorders, such as ischemic cardio cerebro-vascular and neuro-degenerative disease. Breast cancer can indeed be considered as a paradigm of the so-called “common soil” concept, according to which the above mentioned conditions, although having different clinical manifestations, share some pathogenetic mechanisms and risk factors and intermediate predisposing phenotypes (see Type2 diabetes, metabolic syndrome or obesity). In an epidemiological perspective, evidence has been accumulated on the common response of breast cancer and cardiovascular disorders to healthy lifestyles and in particular to the beneficial effects of a close adhesion to the Mediterranean dietary model. The latter would mainly be effective thanks to its anti-inflammatory properties, thus controlling the subclinical condition of low-grade inflammation, a common risk factor of all the “common soil” disorders. Results from the prospective cohort of the Moli-sani Study (nearly 25,000 adults from the general population of the Southern Italy region of Molise) are highly suggestive in this context. In a public health perspective, the “common soil” hypothesis may thus promote the application of preventive strategies, particularly targeting lifestyles, for a broad spectrum of widely prevalent disorders, ranging from breast cancer to myocardial infarction or cognitive impairment conditions
Challenges to the Mediterranean diet at a time of economic crisis.
Aims The traditional Mediterranean diet (MD) is reportedly associated with lower risk of major chronic diseases and long considered to contribute to the reduced rates of cardiovascular and cerebrovascular events and to the highest life expectancy in adults who lived near the Mediterranean Sea. But despite its widely documented health benefits, adherence to this dietary pattern has been rapidly declining over the last decades due to a clear socioeconomic influence. The present review provides an overview of the evidence on the current major determinants of adherence to the Mediterranean diet, with a particular emphasis on Mediterranean Countries at a time of economic crisis; second it explores emerging socioeconomic inequalities in other domains of healthy dietary behaviours such as dietary variety, access to organic foods and food purchasing behaviour. Data synthesis According to ecological evidence, the Mediterranean Countries that used to have the highest adherence to the Mediterranean pattern in the Sixties, more recently experienced the greatest decrease, while Countries in Northern Europe and some other Countries around the world are currently embracing a Mediterranean-like dietary pattern. A potential cause of this downward trend could be the increasing prices of some food items of the Mediterranean diet pyramid. Recent evidence has shown a possible involvement of the economic crisis, material resources becoming strong determinants of the adherence to the MD just after the recession started in 2007-2008. Beyond intake, the MD also encourages increasing dietary diversity, while international dietary recommendations suggest replacing regular foods with healthier ones. Conclusions Socioeconomic factors appear to be major determinants of the adherence to MD and disparities also hold for other indices of diet quality closely related to this dietary pattern
The tenth anniversary as a UNESCO world cultural heritage: an unmissable opportunity to get back to the cultural roots of the Mediterranean diet
In 2010, the Mediterranean diet was awarded the recognition of UNESCO as an Intangible Heritage of Humanity because of its complex interplay between several factors, including skills, knowledge, processing, cooking, and particularly the sharing and consumption of food. Also, the Mediterranean way of eating emphasizes local food, seasonality and biodiversity. Actually, all these aspects are almost completely neglected by the current nutrition research, which rather focuses on amount of food consumed by an individual or a given population but rarely simultaneously considers how foods are matched, whether they are locally-grown or consumed convivially. Basically, nutritional epidemiology usually ends up with classifying populations as highly or poorly adhering to a Mediterranean diet on the basis of the quantity of food consumed with poor or little knowledge on other features of this eating model. As such, this approach is likely to miss important information that could turn out to be as crucial for health as the traditional analysis of food intake. Since a global industrial food system has emerged, traditional diets are facing a global food challenge threating their own survival in the next decades. To transmit the Mediterranean heritage to future generations, it is important to get back to its roots by disentangling the complexity of this diet, which is not merely a healthful model to defeat chronic diseases and improve survival. The Mediterranean diet is a cultural heritage strictly tied to its people and territories. Nutritional epidemiology is now challenged to account for all these aspects in future health research
Ultra-processed foods and nutritional dietary profile : A meta-analysis of nationally representative samples
Excessive consumption of ultra-processed foods (UPFs), as described by the NOVA classification system, represents a potential threat to human health. The nutritional composition of UPFs may explain their observed adverse effects. The present study aimed to provide a quantitative meta-analysis of nationally representative surveys on the consumption of UPFs and the dietary/nutrient composition of respondents’ diets. A systematic search for relevant studies published prior to July 2021 was conducted via electronic databases. The studies that provided the dietary/nutrient composition of foods categorized according to the NOVA classification system were selected. The association between UPFs and other dietary variables was modelled using ordinary least squares linear regression based on aggregated data extracted from the selected articles. Consumption of UPFs represented up to 80% of total caloric intake in the US and Canada, with confectionery and sugar-sweetened beverages being the most consumed items. When considered in relation to other food groups, an inverse linear relation between UPFs and less-processed foods was evident. Increased UPF intake correlated with an increase in free sugars, total fats, and saturated fats, as well as a decrease in fiber, protein, potassium, zinc, and magnesium, and vitamins A, C, D, E, B12, and niacin. In conclusion, the data indicate that increased UPF consumption negatively affects the nutritional quality of diets
Mediterranean Diet and Low-grade Subclinical Inflammation: The Moli-sani Study
Low-grade chronic inflammation is an underlying pathophysiological mechanism linking risk factors and/or metabolic disorders to increased risk of chronic degenerative disease. A meat-based pattern, as the Western type diet, is positively linked to higher levels of some important biomarkers of inflammation, such as C-reactive protein (CRP), interleukin-6 and fibrinogen. Conversely, a Mediterranean-like eating behavior is associated with lower degree of these biomarkers thus suggesting an anti-inflammatory action of its main food components. This chapter goes through the most important investigations addressing the relationship between dietary habits and subclinical inflammation. Attention was focussed on the findings from the Moli-sani study: this is a large prospective cohort study that recruited 24,325 men and women from the general population of the Molise Region, a Southern Italian area, with the aim of investigating genetic and environmental risk/protection factors for cardiovascular and tumor disease. For the first time, the Moli-sani study carefully investigated the Mediterranean diet as an environmental determinant of both platelet and white blood cell counts, starting from the hypothesis that a diet rich in healthy compounds could favorably influence the production and/or the clearance of these two cellular biomarkers of low-grade inflammation. Additionally, evidence from this large Italian cohort showed that a Mediterranean-like diet was closely associated with relatively lower values of glucose, lipids, CRP, blood pressure and 10-year cardiovascular risk, while the consumption of healthy foods with high rather than low content in antioxidant vitamins and phytochemicals was associated with lower blood pressure and CRP plasma levels at least in men
Psychological resilience and cardiovascular disease? A systematic review of the literature
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