32,045 research outputs found
Embracing new ideas: an interview with Maria Leptin. Interview by Kristin H. Kain.
No full textMaria Leptin works simultaneously in the independent fields of immunology and development. She is the new director of the European Molecular Biology Organization (EMBO) and runs a laboratory in Heidelberg, as well as one in Cologne. Here, she describes how she moved between fields and some of the mechanisms that she believes foster creative science
Obesity and the ageing brain : could leptin play a role in neurodegeneration?
No full textObesity and ageing are both characteristics of the human population that are on the increase across the globe. It has long been established that ageing is the major risk factor for neurodegenerative conditions such as Alzheimer’s disease, and it is becoming increasingly evident that obesity is another such factor. Leptin resistance or insensitivity has been uncovered as a cause of obesity, and in addition the leptin signalling system is less potent in the elderly. Taken together, these findings reveal that this molecule may be a link between neurodegeneration and obesity or ageing. It is now known that leptin has beneficial effects on both the survival and neurophysiology of the neurons that are lost in Alzheimer’s disease suggesting that it may be an important research target in the quest for strategies to prevent, halt or cure this condition.Peer reviewe
Obesity: the Role of Leptin
No full textIn Chapter One, Dr Med Ioannis Iakovou examines whether the link between weight and bone mineral density is caused by or directly correlated with leptin and adiponectin. Afterwards, Chapter Two by Martha A. Ramirez, Adrian A. Arellano, Fang Xie, Elizabeth A. Benavides, Robin A. Katchko, Luis Ayala, Alexandra Calderon, Rita A. Flores, Jean M. Escudero, Duane H. Keisler, Randy L. Stanko, and Michelle R. Garcia investigates the link between leptin and infertility issues caused by defects of abnormalitie sin the corpus luteum. Chapter Three by Professor Jaak Jürimäe, PhD investigates the link between leptin and energy intake and expenditure by athletes. In Chapter Four, Renata Saucedo, PhD, Jorge Valencia, PhD, Claudia Gutierrez, and Arturo Zarate, PhD examine the connection between increased leptin levels and insulin resistance. Next, Tiziana Maria Sirangelo analyzes the role between leptin and obesity, explaining that leptin plays a crucial role in the regulation of food intake in Chapter Five. In Chapter Six, Federico Sireci, MD, Francesco Cappello, Frank Rikki Canevari, MD, Francesco Dispenza, MD, Salvatore Gallina, PhD, Pietro Salvago, MD, and Francesco Martines study the peptidergic immunohistochemical manifestation of leptin in laryngeal SCCs
Maria Bersani
No full textLa voce illustra la biografia e l'apporto letterario dato da Maria Bersani alla letteratura per l'infanziaThe headword explains the biography and the contribution of the author Maria Bersani to the children's literatur
Adipokines and cardiometabolic function: how are they interlinked?
No full textObjective
Adipokines contribute directly to the coexistence of insulin resistance and endothelial dysfunction. Most studies focus on a single adipokine. We therefore investigated the independent relationships of leptin, adiponectin, tumor necrosis factor-α, resistin and visfatin, as well as the gut hormone ghrelin with blood pressure and insulin resistance. Secondly we evaluated the interrelationships of adipokines and ghrelin in concert with various cardiometabolic markers.
Methods and Results
Caucasian women (N = 115) with varying levels of obesity (aged 31.3 ± 9.18 years) were included. Significant correlations of leptin, adiponectin, ghrelin and visfatin with mean arterial pressure (p < 0.05) disappeared after adjustment for age, body mass index and waist circumference. But significant correlations with insulin resistance (HOMA) (for leptin, adiponectin and ghrelin) remained significant after adjustments. Factor analyses yielded five factors, but two main clusters, namely a metabolic syndrome cluster (including leptin, adiponectin and ghrelin) and a vascular atherosclerotic cluster (including tumor necrosis factor-α, visfatin and resistin).
Conclusion
Factor analyses identified patterns which indicate specific roles of the various adipokines. Leptin, adiponectin and ghrelin were more closely related to insulin resistance and central obesity as core components of the metabolic syndrome. Visfatin, tumor necrosis factor-α and resistin seem to direct their effects onto the vascular system possibly by means of mechanisms such as inflammation, vasoconstriction and coagulatio
Leptin resensitisation: A reversion of leptin-resistant states
No full textLeptin resistance refers to states in which leptin fails to promote its anticipated effects, frequently coexisting with hyperleptinaemia. Leptin resistance is closely associated with obesity and also observed in physiological situations such as pregnancy and in seasonal animals. Leptin resensitisation refers to the reversion of leptin-resistant states and is associated with improvement in endocrine and metabolic disturbances commonly observed in obesity and a sustained decrease of plasma leptin levels, possibly below a critical threshold level. In obesity, leptin resensitisation can be achieved with treatments that reduce body adiposity and leptinaemia, or with some pharmacological compounds, while physiological leptin resistance reverts spontaneously. The restoration of leptin sensitivity could be a useful strategy to treat obesity, maintain weight loss and/or reduce the recidivism rate for weight regain after dieting. This review provides an update and discussion about reversion of leptin-resistant states and modulation of the molecular mechanisms involved in each situation.Fil: Andreoli, Maria Florencia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Donato, Jose. Universidade de Sao Paulo; BrasilFil: Cakir, Isin. University Brown; Estados Unidos. Vanderbilt University; Estados UnidosFil: Perello, Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; Argentin
Análise de polimorfismo no gene da leptina em bovinos da raça braford
No full textTCC (graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Agrárias. Curso de Agronomia.Os marcadores moleculares em programas de seleção são complementares a seleção clássica, sua utilização permite a antecipação das avaliações nos animais, otimizando o sistema de seleção genética voltada a produção animal. O hormônio leptina e seus receptores são expressos principalmente nos adipócitos e relacionados ao controle da ingestão de alimentos, uso da energia e indicador da condição nutricional do organismo que influenciam em ações de outros sistemas fisiológicos. O presente estudo tem como objetivo verificar a possível existência de polimorfismos em uma região do gene da Leptina em 29 bovinos da raça Braford. O DNA genômico foi extraído de amostras de pelos coletados da vassoura da cauda dos animais. Os resultados obtidos com os procedimentos de extração do DNA foram bastante satisfatórios, onde todas as amostras apresentaram concentração igual ou superior a 100 ng/ uL. Entretanto, os resultados obtidos na Reação em Cadeia da Polimerase (PCR) com o par de iniciadores utilizado neste estudo não foram eficientes, indicando a necessidade de maiores ajustes para viabilização do isolamento e amplificação da região de interesse do gene da Leptina antes de realizar a etapa de Análise de Polimorfismo do Tamanho do Fragmento de Restrição (RFLP).With the technology of Molecular Marked Assisted Selection genetic evaluations and progress of classic traits can be improved. The Leptin hormone and its receptors are expressed mainly in adipocytes and have a important role on ingestion control, energy metabolism and corporal conditions of animals. The present study was carried on intent to verify the possibly existence of genetic polymorphisms in structural region of Leptin`s gene from 29 animal of Braford breed. The genomic DNA was extracted from samples of hairs from animals tails. The results obtained with DNA extraction procedures were satisfactory, with samples showing concentration levels from 100 ng/UL. However, the results obtained in the Polymerase Chain Reaction (PCR) with primers designed to this study, indicating the necessity of further studies to adjust these step, permitting the isolation and amplification of leptin gene before the application in the Restriction Fragment Length Polymorphism (RFLP) to verify the existence of polymorphisms
Variations on the Author
No full text“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
Effects of smoking cessation on serum leptin and adiponectin levels
No full textBackground: Evidence on the association of leptin and adiponectin and smoking is limited and discordant. Leptin and adiponectin represent the most abundant adipokines in human plasma that play crucial roles in the pathophysiology of metabolic syndrome, atherosclerosis and insulin resistance. Leptin up-regulates the expression of several pro-inflammatory cytokines and is increased upon weight gain. Adiponectin has been shown to possess insulin sensitizing, anti -inflammatory and anti-atherogenic properties and is increased upon weight reduction. Our aim was to assess the effects of smoking cessation on serum leptin and adiponectin levels. Methods: We assessed the changes in serum leptin and adiponectin levels, serum CRP levels and BMI in apparently healthy smokers after 3 and 6 months of abstinence from smoking. Successful cessation was confirmed by an exhaled carbon monoxide measurement. 26 healthy non-smokers were recruited as controls. Results: Among the sample group, 32 subjects had quitted smoking at 3 months and 29 subjects at 6 months. Samples' leptin increased significantly from baseline to three months (mean change 3.76 ng/ml [95 % CI 0.89, 6.64], p = 0.012) and then decreased significantly from three to six months of smoking cessation (mean change -4,29 ng/ml [95 % CI -7.34, -6.64], p = 0.008). Samples' adiponectin increased significantly from baseline to three months of abstinence from smoking (mean change 2.34 [95 % CI -0.05, 4.73], p -0.05). BMI was significantly increased (mean change 2.03 kg/m(2) [95 % CI 1.60, 2.46], p < 0.05), while CRP decreased significantly from baseline to 6 months of smoking cessation (mean change -0.68 mg/dl [95 % CI -1.06, -0.30], p = 0.001). Conclusions: Smoking quitters' leptin levels appear to increase 3 months after smoking cessation and then decrease from 3 to 6 months of abstinence from smoking. Adiponectin levels increase during the first trimester of smoking cessation. The decrease in CRP levels indicates that the low grade inflammation observed in smokers is gradually restored. The alterations of serum leptin and adiponectin after 6 months of smoking cessation suggest the same but do not reach statistically significant levels. Weight gain and changes in fat distribution may attenuate the beneficial effects of smoking cessation
Alterations in brain leptin signalling in spite of unchanged CSF leptin levels in Alzheimer’s disease
No full textSeveral studies support the relation between leptin and Alzheimer’s disease (AD). We show that leptin levels in CSF are unchanged as subjects progress to AD. However, in AD hippocampus, leptin signalling was decreased and leptin localization was shifted, being more abundant in reactive astrocytes and less in neurons. Similar translocation of leptin was found in brains from Tg2576 and apoE4 mice. Moreover, an enhancement of leptin receptors was found in hippocampus of young Tg2576 mice and in primary astrocytes and neurons treated withAb1-42. In contrast, old Tg2576 mice showed decreased leptin receptors levels. Similar findings to those seen in Tg2576 mice were found in apoE4, but not in apoE3 mice. These results suggest that leptin levels are intact, but leptin signalling is impaired in AD. Thus, Ab accumulation and apoE4 genotype result in a transient enhancement of leptin signalling that might lead to a leptin resistance state over time
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