1,721,038 research outputs found
Eating disorders: from bench to bedside and back
No full textThe central nervous system and viscera constitute a functional ensemble, the gut-brain axis, that allows bidirectional information flow that contributes to the control of feeding behavior based not only on the homeostatic, but also on the hedonic aspects of food intake. The prevalence of eating disorders, such as anorexia nervosa, binge eating and obesity, poses an enormous clinical burden, and involves an ever-growing percentage of the population worldwide. Clinical and preclinical research is constantly adding new information to the field and orienting further studies with the aim of providing a foundation for developing more specific and effective treatment approaches to pathological conditions. A recent symposium at the XVI Congress of the Societá Italiana di Neuroscienze (SINS, 2015) 'Eating disorders: from bench to bedside and back' brought together basic scientists and clinicians with the objective of presenting novel perspectives in the neurobiology of eating disorders. Clinical studies presented by V. Ricca illustrated some genetic aspects of the psychopathology of anorexia nervosa. Preclinical studies addressed different issues ranging from the description of animal models that mimic human pathologies such as anorexia nervosa, diet-induced obesity, and binge eating disorders (T. Lutz), to novel interactions between peripheral signals and central circuits that govern food intake, mood and stress (A. Romano and G. Provensi). The gut-brain axis has received increasing attention in the recent years as preclinical studies are demonstrating that the brain and visceral organs such as the liver and guts, but also the microbiota are constantly engaged in processes of reciprocal communication, with unexpected physiological and pathological implications. Eating is controlled by a plethora of factors; genetic predisposition, early life adverse conditions, peripheral gastrointestinal hormones that act directly or indirectly on the central nervous system, all are receiving attention as they presumably contribute to the development of eating disorders
Brain Histamine Is Crucial for Selective Serotonin Reuptake Inhibitors' Behavioral and Neurochemical Effects
Full text linkBACKGROUND:
The neurobiological changes underlying depression resistant to treatments remain poorly understood, and failure to respond to selective serotonin reuptake inhibitors may result from abnormalities of neurotransmitter systems that excite serotonergic neurons, such as histamine.
METHODS:
Using behavioral (tail suspension test) and neurochemical (in vivo microdialysis, Western-blot analysis) approaches, here we report that antidepressant responses to selective serotonin reuptake inhibitors (citalopram or paroxetine) are abolished in mice unable to synthesize histamine due to either targeted disruption of histidine decarboxylase gene (HDC(-/-)) or injection of alpha-fluoromethylhistidine, a suicide inhibitor of this enzyme.
RESULTS:
In the tail suspension test, all classes of antidepressants tested reduced the immobility time of controls. Systemic reboxetine or imipramine reduced the immobility time of histamine-deprived mice as well, whereas selective serotonin reuptake inhibitors did not even though their serotonergic system is functional. In in vivo microdialysis experiments, citalopram significantly increased histamine extraneuronal levels in the cortex of freely moving mice, and methysergide, a serotonin 5-HT1/5-HT2 receptor antagonist, abolished this effect, thus suggesting the involvement of endogenous serotonin. CREB phosphorylation, which is implicated in the molecular mechanisms of antidepressant treatment, was abolished in histamine-deficient mice treated with citalopram. The CREB pathway is not impaired in HDC(-/-) mice, as administration of 8-bromoadenosine 3', 5'-cyclic monophosphate increased CREB phosphorylation, and in the tail suspension test it significantly reduced the time spent immobile by mice of both genotypes.
CONCLUSIONS:
Our results demonstrate that selective serotonin reuptake inhibitors selectively require the integrity of the brain histamine system to exert their preclinical responses
Central mechanisms mediating the hypophagic effects of oleoylethanolamide and N-acylphosphatidylethanolamines: different lipid signals?
Full text linkThe spread of ‘obesity epidemic’ and the poor efficacy of many anti-obesity therapies in the long-term highlight the need to develop novel efficacious therapy. This necessity stimulates a large research effort to find novel mechanisms controlling feeding and energy balance. Among these mechanisms a great deal of attention has been attracted by a family of phospholipid-derived signaling molecules that play an important role in the regulation of food-intake. They include N-acylethanolamines (NAEs) and N-acylphosphatidylethanolamines (NAPEs). NAPEs have been considered for a long time simply as phospholipid precursors of the lipid mediator NAEs, but increasing body of evidence suggest a role in many physiological processes including the regulation of feeding behavior. Several observations demonstrated that among NAEs, oleoylethanolamide (OEA) acts as a satiety signal, which is generated in the intestine, upon the ingestion of fat, and signals to the central nervous system. At this level different neuronal pathways, including oxytocinergic, noradrenergic, and histaminergic neurons, seem to mediate its hypophagic action. Similarly to NAEs, NAPEs (with particular reference to the N16:0 species) levels were shown to be regulated by the fed state and this finding was initially interpreted as fluctuations of NAE precursors. However, the observation that exogenously administered NAPEs are able to inhibit food intake, not only in normal rats and mice but also in mice lacking the enzyme that converts NAPEs into NAEs, supported the hypothesis of a role of NAPE in the regulation of feeding behavior. Indirect observations suggest that the hypophagic action of NAPEs might involve central mechanisms, although the molecular target remains unknown. The present paper reviews the role that OEA and NAPEs play in the mechanisms that control food intake, further supporting this group of phospholipids as optimal candidate for the development of novel anti-obesity treatments
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
D-Tagatose Feeding Reduces the Risk of Sugar-Induced Exacerbation of Myocardial I/R Injury When Compared to Its Isomer Fructose
Full text linkIt is known that fructose may contribute to myocardial vulnerability to ischemia/reperfusion (I/R) injury. D-tagatose is a fructose isomer with less caloric value and used as low-calorie sweetener. Here we compared the metabolic impact of fructose or D-tagatose enriched diets on potential exacerbation of myocardial I/R injury. Wistar rats were randomizedly allocated in the experimental groups and fed with one of the following diets: control (CTRL), 30% fructose-enriched (FRU 30%) or 30% D-tagatose-enriched (TAG 30%). After 24 weeks of dietary manipulation, rats underwent myocardial injury caused by 30 min ligature of the left anterior descending (LAD) coronary artery followed by 24 h′ reperfusion. Fructose consumption resulted in body weight increase (49%) as well as altered glucose, insulin and lipid profiles. These effects were associated with increased I/R-induced myocardial damage, oxidative stress (36.5%) and inflammation marker expression. TAG 30%-fed rats showed lower oxidative stress (21%) and inflammation in comparison with FRU-fed rats. Besides, TAG diet significantly reduced plasmatic inflammatory cytokines and GDF8 expression (50%), while increased myocardial endothelial nitric oxide synthase (eNOS) expression (59%). Overall, we demonstrated that D-tagatose represents an interesting sugar alternative when compared to its isomer fructose with reduced deleterious impact not only on the metabolic profile but also on the related heart susceptibility to I/R injury. © Copyright © 2021 Durante, Sgambellone, Lucarini, Failli, Laurino, Collotta, Provensi, Masini and Collino
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
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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