Leptin Resistance and the Neuro-Adipose Connection

This article was submitted to Cellular Endocrinology, a section of the journal Frontiers in Endocrinology.Obesity is a public health concern affecting both genders at all ages around the world. The worldwide prevalence of obesity is rapidly increasing and has nearly doubled between 1980 and 2016. Consequently, it places a large financial burden on the economy due to the increased morbidity and mortality, as well as the reduced quality of life and development of chronic diseases. Obesity is typically characterized by excessive amounts of the hormone leptin, a cytokine-like molecule produced in white adipose tissue (WAT) that is secreted into the systemic circulation. The circulating levels of leptin are proportional to the amount of fat and function as the afferent signal in a negative feedback loop that seeks to maintain body fat in a very narrow range of variation. Leptin has a central role in body weight homeostasis due to its inhibition of food intake inhibition and stimulation of energy expenditure. The effect of leptin on body weight is attributed to its action in a specific brain region, the hypothalamus. Hence, leptin is released by adipocytes in proportion to the size of fat depots, enters the circulation, and reaches the central nervous system by crossing the blood-brain barrier (BBB) through receptor-mediated endocytosis in which it acts mainly through the arcuate nucleus of the hypothalamus to mediate most of its actions. Specifically, leptin modulates the activity of two types of neurons to inhibit appetite, through production of anorexigenic peptides by the pro-opiomelanocortin (POMC) neurons and suppression of the orexigenic agouti-related protein (AgRP) neurons. Besides acting on the hypothalamus to suppress appetite, leptin also induces lipolysis in WAT and thermogenesis in brown adipose tissue (BAT) and browning of WAT, via the activation of the sympathetic nervous system (SNS). However, in most obese subjects, despite its high serum levels, leptin fails to perform its physiological functions and consequently fails to reduce weight. This effect has been coined as leptin resistance.Fundação para Ciência e Tecnologia grants: (PD/BD/52437/2013, PTDC-BIM-MET-3750-2014); EMBO grant: (IG3077); Prémios Maratona Saúde 2015: (Diabetes); Human Frontiers Science Program grant:(RGY0070/2016).info:eu-repo/semantics/publishedVersio

The reward value of sucrose in leptin-deficient obese mice

Leptin-deficient patients report higher "liking" ratings for food, and leptin replacement therapy normalizes these ratings even before weight loss is achieved. Since animals cannot report their ratings, we studied the relationship between leptin and food reward in leptin-deficient ob/ob mice using a optogenetic assay that quantifies the reward value of sucrose. In this assay, mice chose between one sipper dispensing the artificial sweetener sucralose coupled to optogenetic activation of dopaminergic (DA) neurons, and another sipper dispensing sucrose. We found that the reward value of sucrose was high under a state of leptin deficiency, as well as at a dose of leptin that does not suppress food intake (12.5 ng/h). Treatment with higher doses of leptin decreased the reward value of sucrose before weight loss was achieved (100 ng/h), as seen in leptin-deficient patients. These results phenocopy in mice the behavior of leptin-deficient patients.JPB Foundation; The Klarman Family Foundation for Eating Disorders; The Rockefeller Foundation; Gulbenkian Foundation; FCT

Contributions to the design of mobile applications for visitors of Botanical Gardens

Botanical Gardens are among the most visited touristic attractions, offering scientific, educational, cultural and leisure activities to preserve and enhance heritage and disseminating specialised knowledge on science and history. There are several mobile applications (apps) to support visitors of Botanical Gardens, which explore augmented reality technologies to enrich their experience. Our work aims to systematize a set of requirements that must be considered in the development of these apps. We have applied them in the development of an app for a Botanical Garden available for Android and iOS. Preliminary data analysis of the use of our app revealed some characteristics of the visitors and the preferred tours. Meanwhile we are evaluating our app by conducting a user study.info:eu-repo/semantics/publishedVersio

Leptin regulates the reward value of nutrient

We developed an assay for quantifying the reward value of nutrient and used it to analyze the effects of metabolic state and leptin. In this assay, mice chose between two sippers, one of which dispensed water and was coupled to optogenetic activation of dopaminergic (DA) neurons and the other of which dispensed natural or artificial sweeteners. This assay measured the reward value of sweeteners relative to lick-induced optogenetic activation of DA neurons. Mice preferred optogenetic stimulation of DA neurons to sucralose, but not to sucrose. However, the mice preferred sucralose plus optogenetic stimulation versus sucrose. We found that food restriction increased the value of sucrose relative to sucralose plus optogenetic stimulation, and that leptin decreased it. Our data suggest that leptin suppresses the ability of sucrose to drive taste-independent DA neuronal activation and provide new insights into the mechanism of leptin's effects on food intake

Psicologia da Saúde: Extensão de serviços à comunidade, ensino e pesquisa.

Les psychologues ont un rôle croissant dans le secteur médical. Ce rapport a pour objectif de décrire le développement et le stade actuel du Service de Psychologie de l’Hôpital de Base de la FAMERP, commencé en 1981 par l’embauche d’une psychologue pour travailler à l’infirmerie de pédiatrie. Aujourd’hui, l’hôpital compte 40 psychologues (professeurs, superviseurs et résidents) qui développent des activités d’extension de services à la communauté, d’enseignement et de recherche en Psychologie Médicale. Ces activités comprennent les niveaux primaires, secondaire et tertiaire de soins en urgence, à l’hôpital, au centre Hospitalier Universitaire, principalement en équipes interdisciplinaires. L’enseignement comprend des cours de 3ème cycle en médecine et infirmerie, des stages pour des étudiants en psychologie, un programme de Perfectionnement en Psychologie de la Santé, Cours de Spécialisation, de Spécialisation professoral, de recherches du programme de post-graduation en Sciences de la santé (maîtrise et doctorat) à la FAMERP. Les recherches visent principalement l’étude des relations entre comportement et santé, en abordant des thèmes comme la promotion de la santé, de la prévention et l’aide au traitement et lê manège des maladies. Bien que ce secteur soit en expansion, il faut penser que l’entretien de la crédibilité et de l’espace conquis dépendent d’une solide formation professionnelle, d’éthique et de développement des recherches dans ce secteur.O trabalho de psicólogos na área da saúde vem se desenvolvendo de form a crescente. O objetivo deste relato é descrever o desenvolvimento e estágio atual do Serviço de Psicologia do Hospital de Base da FAMERP, iniciado em 1981 com a contratação de uma psicóloga para atuar na enfermaria de Pediatria. Atualmente, o hospital conta com 40 psicólogos (docentes, contratados e aprimorandos) desenvolvendo atividades de extensão de serviços à comunidade, ensino e pesquisa em Psicologia da Saúde. A atuação abrange os níveis primário, secundário e terciário de atendimento e é realizada no ambulatório, no hospital, em Centro de Saúde Escola e na comunidade, principalmente em equipes interdisciplinares. O ensino envolve aulas para os cursos de graduação em medicina e enfermagem, estágio para alunos de psicologia, um Programa de Aprimoramento em Psicologia da Saúde, Cursos de Extensão, de Especialização e docência e orientação no Programa de Pós-Graduação em Ciências da Saúde (mestrado e doutorado) da FAMERP. As pesquisas visam principalmente o estudo das relações entre comportamento e saúde, abordando temas como promoção da saúde, prevenção e auxílio no tratamento e manejo de doenças. Embora a área esteja em expansão, é preciso pensar que a manutenção da credibilidade e do espaço conquistado dependem de uma sólida formação profissional, de um desempenho ético e do desenvolvimento de pesquisas na área.Psychologists have had an increasing role in the medical area. The objective of this study is to report the development and current status of the Psychology Service at Hospital de Base, São José do Rio Preto Medical School (FAMERP), which started in 1981, when a psychologist was hired to work at the Pediatrics Outpatient Ward. Currently, the hospital has a staff of 40 psychologists (professors, supervisors, and residents), developing community services, education and research activities in Health Psychology. Such activities are carried out at a primary, secondary and tertiary level at the outpatient ward of the hospital and at a Medical School Health Community Center, especially with interdisciplinary teams. Teaching involves classes in post-graduation courses in medicine and nursing; internships for psychology students; a Residency Program in Health Psychology; Extension, Specialization, and Teaching Courses; and assistance to graduate students from the Post-Graduation Program in Health Sciences (masters degree and PhD) at FAMERP. Research is aimed at assessing the relationship between behavior and health, approaching issues such as providing health, prevention and assistance in the treatment and management of diseases. Even though this is an expanding area, the maintenance of credibility and the progress achieved depend on a solid professional training, ethics and the development of research in the area

Exploring the solid state and solution structural chemistry of the utility amide potassium hexamethyldisilazide (KHMDS)

The structural chemistry of eleven donor complexes of the important Brønsted base potassium 1,1,1,3,3,3-hexamethyldisilazide (KHMDS) has been studied. Depending on the donor, each complex adopted one of four general structural motifs. Specifically, in this study the donors employed were toluene (to give polymeric 1 and dimeric 2), THF (dimeric 3), N,N,N',N'-tetramethylethylenediamine (TMEDA) (dimeric 4), (R,R)-N,N,N',N'-tetramethyl-1,2-diaminocyclohexane [(R,R)-TMCDA] (dimeric 5), 12-crown-4 (dimeric 6), N,N,N',N'-tetramethyldiaminoethyl ether (TMDAE) (tetranuclear dimeric 8 and monomeric 10), N,N,N',N',N''-pentamethyldiethylentriamine (PMDETA) (tetranuclear dimeric 7), tris[2-dimethyl(amino)ethyl]amine (Me6TREN) (tetranuclear dimeric 9) and tris{2-(2-methoxyethoxy)ethyl}amine (TMEEA) (monomeric 11). The complexes were also studied in solution by 1H and 13C NMR spectroscopy as well as DOSY NMR spectroscopy

The diversity and evolution of pollination systems in large plant clades: Apocynaceae as a case study

Background and Aims Large clades of angiosperms are often characterized by diverse interactions with pollinators, but how these pollination systems are structured phylogenetically and biogeographically is still uncertain for most families. Apocynaceae is a clade of >5300 species with a worldwide distribution. A database representing >10 % of species in the family was used to explore the diversity of pollinators and evolutionary shifts in pollination systems across major clades and regions. Methods The database was compiled from published and unpublished reports. Plants were categorized into broad pollination systems and then subdivided to include bimodal systems. These were mapped against the five major divisions of the family, and against the smaller clades. Finally, pollination systems were mapped onto a phylogenetic reconstruction that included those species for which sequence data are available, and transition rates between pollination systems were calculated. Key Results Most Apocynaceae are insect pollinated with few records of bird pollination. Almost three-quarters of species are pollinated by a single higher taxon (e.g. flies or moths); 7 % have bimodal pollination systems, whilst the remaining approx. 20 % are insect generalists. The less phenotypically specialized flowers of the Rauvolfioids are pollinated by a more restricted set of pollinators than are more complex flowers within the Apocynoids + Periplocoideae + Secamonoideae + Asclepiadoideae (APSA) clade. Certain combinations of bimodal pollination systems are more common than others. Some pollination systems are missing from particular regions, whilst others are over-represented. Conclusions Within Apocynaceae, interactions with pollinators are highly structured both phylogenetically and biogeographically. Variation in transition rates between pollination systems suggest constraints on their evolution, whereas regional differences point to environmental effects such as filtering of certain pollinators from habitats. This is the most extensive analysis of its type so far attempted and gives important insights into the diversity and evolution of pollination systems in large clades

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types