1,721,036 research outputs found
Reincarnated medicines: using out-dated drugs for novel indications
No full textSociety today normally considers that something is better, just because
it is newer. This is true for many consumer products such as
motor vehicles, cellular telephones, computers, televisions, etc.We
immediately think that newer means high performance, improvement,
a step above. But is this always true? More specifically, does
this apply to healthcare? Granted, many new drugs and devices
are approved every year but this does not mean that newer is always
better and worth the extra cost. Research shows that, in some
cases, existing drugs and devices can be as good if not better, safer,
and cheaper than completely new ones. It follows that ‘new’ can
have several meanings. When we come to healthcare, assuming
that ‘new’ is always better can be very costly. Reconsidering or repurposing
old drugs could be an interesting opportunity—let’s
hope
SGLT2 inhibitors: from glucose-lowering to cardiovascular benefits
No full textAn increasing number of individuals is at high risk of type 2 diabetes (T2D) and its cardiovascular complications, including heart failure (HF), chronic kidney disease (CKD), and premature death. The sodium-glucose cotransporter-2 (SGLT2) protein sits in the proximal tubule of human nephrons to regulate glucose reabsorption, and its inhibition by gliflozins represents the cornerstone of contemporary T2D and HF management. Herein, we aim to provide an updated view on the pleiotropy of gliflozins, provide mechanistic insights and delineate related cardiovascular (CV) benefits. By discussing contemporary evidence obtained in preclinical models and landmark randomized controlled trials, we move from bench to bedside across the broad spectrum of cardio- and cerebrovascular diseases. With robust trials confirming a reduction in major adverse CV events (MACE; composite endpoint of CV death, non-fatal myocardial infarction, and non-fatal stroke), SGLT2 inhibitors strongly mitigate the risk for heart failure hospitalization in diabetics and non-diabetics alike while conferring renoprotection in specific patient populations. Along four major pathophysiological axes (ie, at cardiac, vascular, renal, and systemic levels), we provide insights into key mechanisms that may underlie their beneficial effects, including gliflozins' role in the modulation of vascular inflammation, oxidative stress, cellular energy metabolism and housekeeping mechanisms. We also discuss how this drug class controls hyperglycaemia, ketogenesis, natriuresis, and hyperuricaemia, contributing to their pleiotropic effects. Finally, evolving data in the setting of cerebrovascular diseases and arrythmias are presented, and potential implications for future research and clinical practice are comprehensively reviewed
Enhanced age-dependent cerebrovascular dysfunction is mediated by adaptor protein p66Shc
No full textBACKGROUND: Aging is an independent risk factor for cardiovascular and cerebrovascular disease. To date, little is known about the mechanisms of aging of cerebral arteries and whether the aging gene p66(Shc) is implicated in it. The present study was designed to assess age-induced vascular dysfunction in cerebral and systemic arteries of wild type (wt) and p66(Shc-/-) mice.
METHODS: Basilar arteries and size matched second order femoral arteries of 3-month (3M), 6-month (6M) and 2-year old (2Y) mice were studied in wt and p66(Shc-/-) mice. To assess vascular function, arterial rings mounted in a myograph for isometric tension recordings were exposed to increasing concentrations of acetylcholine and sodium nitroprusside. Reactive oxygen species (ROS) generation was assessed in femoral and basilar arteries using the spin trap 1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine.
RESULTS: In wt mice, endothelial function of the femoral artery was not affected by age unlike in the basilar artery where an age-dependent dysfunction was observed. In p66(Shc-/-) a similar response was observed in the femoral artery; however, age-dependent endothelial dysfunction of the basilar artery was blunted as compared to wt. Levels of ROS were comparable in the femoral arteries of 3M and 2Y of wt and p66(Shc-/-) mice. Differently, ROS levels in the basilar artery of wt mice were strongly increased by age unlike in p66(Shc-/-) mice where they remained comparable irrespective of age.
CONCLUSIONS: Endothelial function in cerebral arteries, but not in size-matched systemic ones, is heavily impaired by aging. This process is paralleled by an increased ROS production and is mediated by the p66(Shc) gene
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
Epigenetics and cardiovascular regenerative medicine in the elderly
No full textDkk-3 is a member of the dickkopf protein family of secreted inhibitors of the Wnt pathway, which has been shown to enhance angiogenesis. The mechanism underlying this effect is currently unknown. Here, we used cultured HUVECs to study the involvement of the TGF-β and VEGF on the angiogenic effect of Dkk-3. Addition of hrDkk-3 peptide (1 or 10 ng/ml) to HUVECs for 6 or 12 h enhanced the intracellular and extracellular VEGF protein levels, as assessed by RTPCR, immunoblotting, immunocytochemistry and ELISA. The increase in the extracellular VEGF levels was associated to the VEGFR2 activation. Pharmacological blockade of VEGFR2 abrogated Dkk-3-induced endothelial cell tubes formation, indicating that VEGF is a molecular player of the angiogenic effects of Dkk-3. Moreover, Dkk-3 enhanced Smad1/5/8 phosphorylation and recruited Smad4 to the VEGF gene promoter, suggesting that Dkk-3 activated ALK1 receptor leading to a transcriptional activation of VEGF. This mechanism was instrumental to the increased VEGF expression and endothelial cell tubes formation mediated by Dkk-3, because both effects were abolished by siRNA-mediated ALK1 knockdown. In summary, we have found that Dkk-3 activates ALK1 to stimulate VEGF production and induce angiogenesis in HUVECs
Ischemic stroke across sexes: What is the status quo?
No full textStroke prevalence is expected to increase in the next decades due to the aging of the Western population. Ischemic stroke (IS) shows an age- and sex-dependent distribution in which men represent the most affected population within 65 years of age, being passed by post-menopausal women in older age groups. Furthermore, a sexual dimorphism concerning risk factors, presentation and treatment of IS has been widely recognized. In order to address these phenomena, a number of issue have been raised involving both socio-economical and biological factors. The latter can be either dependent on sex hormones or due to intrinsic factors. Although women have poorer outcomes and are more likely to die after a cerebrovascular event, they are still underrepresented in clinical trials and this is mirrored by the lack of sex-tailored therapies. A greater effort is needed in the future to ensure improved treatment and quality of life to both sexes
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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