7,005 research outputs found

    Pharmacological potential of methylxanthines: Retrospective analysis and future expectations

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    Methylated xanthines (methylxanthines) are available from a significant number of different botanical species. They are ordinarily included in daily diet, in many extremely common beverages and foods. Caffeine, theophylline and theobromine are the main methylxanthines available from natural sources. The supposedly relatively low toxicity of methylxanthines, combined with the many beneficial effects that have been attributed to these compounds through time, generated a justified attention and a very prolific ground for dedicated scientific reports. Methylxanthines have been widely used as therapeutical tools, in an intriguing range of medicinal scopes. In fact, methylxanthines have been/were medically used as Central Nervous System stimulants, bronchodilators, coronary dilators, diuretics and anti-cancer adjuvant treatments. Other than these applications, methylxanthines have also been hinted to hold other beneficial health effects, namely regarding neurodegenerative diseases, cardioprotection, diabetes and fertility. However, it seems now consensual that toxicity concerns related to methylxanthine consumption and/or therapeutic use should not be dismissed. Taking all the knowledge and expectations on the potential of methylxanthines into account, we propose a systematic look at the past and future of methylxanthine pharmacologic applications, discussing all the promise and anticipating possible constraints. Anyways, methylxanthines will still substantiate considerable meaningful research and discussion for years to come.info:eu-repo/semantics/publishedVersio

    Editorial

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    Metabolic disorders, particularly Diabetes Mellitus (DM), are major causes of death worldwide. In fact, the world statistics for DM are alarming: this epidemic disease kills one person every six seconds, being the fourth cause of death. Besides the health issues, the costs associated with DM, and its co-morbidities, are massive and the pressure in National Health Care Systems is dramatically increasing. Patients with DM, particularly those with type 2 diabetes (T2D), are primarily advised to change their dietary habits and exercise regime. However, as the disease progresses and becomes more severe, conventional drugs are prescribed. Most of these patients need polypharmacological therapy and though progresses have been made, efforts are mandatory in a search for a “perfect” antidiabetic drug. [...]info:eu-repo/semantics/publishedVersio

    Obesity, energy balance and spermatogenesis

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    Obesity has grown to pandemic proportions. It affects an increasing number of children, adolescents and young adults exposed to the silent comorbidities of this disorder for a longer period. Infertility has arisen as one important comorbidity associated with the energy dysfunction promoted by obesity. Spermatogenesis is a highly regulated process that is determined by specific energetic requirements. The reproductive potential of males relies on hormonal-dependent and -independent stimuli that control sperm quality. There are conflicting data concerning the impact of male overweight and obesity on sperm quality, as well as on the possible paternal-induced epigenetic trait inheritance of obesity. In addition, it remains a matter of debate whether massive weight loss induced by lifestyle interventions, drugs or bariatric surgery may or may not benefit obese men seeking fatherhood. Herein, we propose to discuss how energy balance may modulate hormonal signalling and sperm quality in overweight and obese men. We also discuss some molecular mechanisms that mediate obesity-related dysfunction in male reproductive system and how paternal obesity may lead to trait inheritance. Finally, we will discuss how lifestyle modifications and sustained weight loss, particularly the loss achieved by bariatric surgery, may revert some of the deleterious effects of obesity in men and their offspring.info:eu-repo/semantics/publishedVersio

    Extracellular Vesicles, the Road toward the Improvement of ART Outcomes

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    Nowadays, farm animal industries use assisted reproductive technologies (ART) as a tool to manage herds’ reproductive outcomes, for a fast dissemination of genetic improvement as well as to bypass subfertility issues. ART comprise at least one of the following procedures: collection and handling of oocytes, sperm, and embryos in in vitro conditions. Therefore, in these conditions, the interaction with the oviductal environment of gametes and early embryos during fertilization and the first stages of embryo development is lost. As a result, embryos obtained in in vitro fertilization (IVF) have less quality in comparison with those obtained in vivo, and have lower chances to implant and develop into viable offspring. In addition, media currently used for IVF are very similar to those empirically developed more than five decades ago. Recently, the importance of extracellular vesicles (EVs) in the fertility process has flourished. EVs are recognized as effective intercellular vehicles for communication as they deliver their cargo of proteins, lipids, and genetic material. Thus, during their transit through the female reproductive tract both gametes, oocyte and spermatozoa (that previously encountered EVs produced by male reproductive tract) interact with EVs produced by the female reproductive tract, passing them important information that contributes to a successful fertilization and embryo development. This fact highlights that the reproductive tract EVs cargo has an important role in reproductive events, which is missing in current ART media. This review aims to recapitulate recent advances in EVs functions on the fertilization process, highlighting the latest proposals with an applied approach to enhance ART outcome through EV utilization as an additive to the media of current ART procedures

    Spontaneous symmetry breaking in amnestically induced persistence

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    We investigate a recently proposed non-Markovian random walk model characterized by loss of memories of the recent past and amnestically induced persistence. We report numerical and analytical results showing the complete phase diagram, consisting of 4 phases, for this system: (i) classical nonpersistence, (ii) classical persistence (iii) log-periodic nonpersistence and (iv) log-periodic persistence driven by negative feedback. The first two phases possess continuous scale invariance symmetry, however log-periodicity breaks this symmetry. Instead, log-periodic motion satisfies discrete scale invariance symmetry, with complex rather than real fractal dimensions. We find for log-periodic persistence evidence not only of statistical but also of geometric self-similarity.Comment: 4 pages, 2 color fig

    Lifestyle, metabolic disorders and male hypogonadism - a one-way ticket?

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    Hypogonadism is more frequent among men with common metabolic diseases, notably obesity and type 2 diabetes. Indeed, endocrine disruption caused by metabolic diseases can trigger the onset of hypogonadism, although the underlying molecular mechanisms are not entirely understood. Metabolic diseases are closely related to unhealthy lifestyle choices, such as dietary habits and sedentarism. Therefore, hypogonadism is part of a pathological triad gathering unhealthy lifestyle, metabolic disease and genetic background. Additionally, hypogonadism harbors the potential to aggravate underlying metabolic disorders, further sustaining the mechanisms leading to disease. To what extent does lifestyle intervention in men suffering from these metabolic disorders can prevent, improve or reverse hypogonadism, is still controversial. Moreover, recent evidence suggests that the metabolic status of the father is related to the risk of inter and transgenerational inheritance of hypogonadism. In this review, we will address the proposed mechanisms of disease, as well as currently available interventions for hypogonadism.publishe

    Testicular "Inherited Metabolic Memory" of Ancestral High-Fat Diet Is Associated with Sperm sncRNA Content

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    Funding: This work was supported by the Portuguese Foundation for Science and Technology: L. Crisóstomo (SFRH/BD/128584/2017), M.G. Alves (PTDC/MEC-AND/28691/2017), UMIB (UIDB/00 215/2020 and UIDP/00215/2020), and ITR (LA/P/0064/2020) and co-funded by FEDER funds (POCI/COMPETE 2020) and by the Portuguese Society of Diabetology: L. Crisóstomo and M.G. Alves (“Nuno Castel-Branco” research grant and Group of Fundamental and Translational Research).publishersversionpublishe

    An integrated view

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    Funding Information: This work was supported by “Fundação para a Ciência e a Tecnologia”—FCT MJM (PD/BD/114256/2016), MPM (PTDC/BIM-MET/4265/2014 and PTDC/MEC-MET/29314/2017), MGA (PTDC/BIM-MET/4712/2014), iNOVA4Health (UIDB/Multi/04462/2020), by the European Commission Marie Skłodowska-Curie Action H2020 (mtFOIE GRAS, grant agreement n. 734719), by the Sociedade Portuguesa de Diabetologia, and by the research infrastructure CONGENTO, project LISBOA-01-0145-FEDER-022170, co-financed by Lisboa Regional Operational Programme (Lisboa2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund and by Fundação para a Ciência e Tecnologia (Portugal). NMR data were collected at the UC-NMR facility which is supported in part by FEDER – European Regional Development Fund through the COMPETE Programme (Operational Programme for Competitiveness) and by National Funds through FCT – Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) through grants REEQ/481/QUI/2006, RECI/QEQ-QFI/0168/2012, CENTRO-07-CT62-FEDER-002012, and Rede Nacional de Ressonância Magnética Nuclear (RNRMN). Publisher Copyright: Copyright © 2022 Meneses, Sousa-Lima, Jarak, Raposo, Alves and Macedo.Objective: In the last years, changes in dietary habits have contributed to the increasing prevalence of metabolic disorders, such as non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM). The differential burden of lipids and fructose on distinct organs needs to be unveiled. Herein, we hypothesized that high-fat and high-fructose diets differentially affect the metabolome of insulin-sensitive organs such as the liver, muscle, and different adipose tissue depots. Methods: We have studied the impact of 12 weeks of a control (11.50% calories from fat, 26.93% from protein, and 61.57% from carbohydrates), high-fat/sucrose (HFat), or high-fructose (HFruct) feeding on C57Bl/6J male mice. Besides glucose homeostasis, we analyzed the hepatic levels of glucose and lipid-metabolism-related genes and the metabolome of the liver, the muscle, and white (WAT) and brown adipose tissue (BAT) depots. Results: HFat diet led to a more profound impact on hepatic glucose and lipid metabolism than HFruct, with mice presenting glucose intolerance, increased saturated fatty acids, and no glycogen pool, yet both HFat and HFruct presented hepatic insulin resistance. HFat diet promoted a decrease in glucose and lactate pools in the muscle and an increase in glutamate levels. While HFat had alterations in BAT metabolites that indicate increased thermogenesis, HFruct led to an increase in betaine, a protective metabolite against fructose-induced inflammation. Conclusions: Our data illustrate that HFat and HFruct have a negative but distinct impact on the metabolome of the liver, muscle, WAT, and BAT.publishersversionpublishe

    Amnestically induced persistence in random walks

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    We study how the Hurst exponent α\alpha depends on the fraction ff of the total time tt remembered by non-Markovian random walkers that recall only the distant past. We find that otherwise nonpersistent random walkers switch to persistent behavior when inflicted with significant memory loss. Such memory losses induce the probability density function of the walker's position to undergo a transition from Gaussian to non-Gaussian. We interpret these findings of persistence in terms of a breakdown of self-regulation mechanisms and discuss their possible relevance to some of the burdensome behavioral and psychological symptoms of Alzheimer's disease and other dementias.Comment: 4 pages, 3 figs, subm. to Phys. Rev. Let

    The Action of Polyphenols in Diabetes Mellitus and Alzheimer's Disease: A Common Agent for Overlapping Pathologies

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    Diabetes Mellitus (DM) and Alzheimer's disease (AD) are two prevalent diseases in modern societies, which are caused mainly by current lifestyle, aging and genetic alterations. It has already been demonstrated that these two diseases are associated, since individuals suffering from DM are prone to develop AD. Conversely, it is also known that individuals with AD are more susceptible to DM, namely type 2 diabetes (T2DM). Therefore, these two pathologies, although completely different in terms of symptomatology, end up sharing several mechanisms at the molecular level, with the most obvious being the increase of oxidative stress and inflammation. Polyphenols are natural compounds widely spread in fruits and vegetables whose dietary intake has been considered inversely proportional to the incidence of DM and AD. So, it is believed that this group of phytochemicals may have preventive and therapeutic potential, not only by reducing the risk and delaying the development of these pathologies, but also by improving brain's metabolic profile and cognitive function. The aim of this review is to understand the extent to which DM and AD are related pathologies, the degree of similarity and the relationship between them, to detail the molecular mechanisms by which polyphenols may exert a protective effect, such as antioxidant and anti-inflammatory effects, and highlight possible advantages of their use as common preventive and therapeutic alternatives.info:eu-repo/semantics/publishedVersio
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