Regional specific effect of saturated vs unsaturated fat on leptin receptor signalling in mice brain areas regulating feeding.

Leptin receptors (LepR) are expressed in brain areas controlling food intake homeostasis, such as the hypothalamus, the hippocampus and the prefrontal cortex. In a previous study we reported that long-term intake of saturated and monounsaturated fat alters hypothalamic LepR signalling. The current study aims at investigating the effect of foods high in either saturated (SOLF) or monounsaturated fat (UOLF) on LepR functionality in the hippocampus and the prefrontal cortex. Male mice were placed on SOLF/UOLF (eight weeks), then treated with recombinant murine leptin (1 mg/kg). After 60 min, brain regions were dissected and processed for western blot of phosphorylated STAT3 (pSTAT3), Akt (pAkt) and AMPK (pAMPK). Levels of SOCS3 were also quantified. SOLF itself increased basal levels of pSTAT3, while UOLF impaired leptin-induced phosphorylation of both Akt and AMPK. SOCS3 levels were specifically increased by UOLF within the prefrontal cortex. Our results show that SOLF and UOLF differently affect LepR signalling within the hippocampus and the prefrontal cortex, which points to the complex effect of saturated and unsaturated fat on brain function, particularly in areas regulating food intake.

Effects of saturated versus unsaturated fatty acids on metabolism, gliosis, and hypothalamic leptin sensitivity in male mice.

BACKGROUND: Development of obesity and its comorbidities is not only the result of excess energy intake, but also of dietary composition. Understanding how hypothalamic metabolic circuits interpret nutritional signals is fundamental to advance towards effective dietary interventions. OBJECTIVE: We aimed to determine the metabolic response to diets enriched in specific fatty acids. METHODS: Male mice received a diet enriched in unsaturated fatty acids (UOLF) or saturated fatty acids (SOLF) for 8 weeks. RESULTS: UOLF and SOLF mice gained more weight and adiposity, but with no difference between these two groups. Circulating leptin levels increased on both fatty acid-enriched diet, but were higher in UOLF mice, as were leptin mRNA levels in visceral adipose tissue. In contrast, serum non-esterified fatty acid levels only rose in SOLF mice. Hypothalamic mRNA levels of NPY decreased and of POMC increased in both UOLF and SOLF mice, but only SOLF mice showed signs of hypothalamic astrogliosis and affectation of central fatty acid metabolism. Exogenous leptin activated STAT3 in the hypothalamus of all groups, but the activation of AKT and mTOR and the decrease in AMPK activation in observed in controls and UOLF mice was not found in SOLF mice. CONCLUSIONS: Diets rich in fatty acids increase body weight and adiposity even if energy intake is not increased, while increased intake of saturated and unsaturated fatty acids differentially modify metabolic parameters that could underlie more long-term comorbidities. Thus, more understanding of how specific nutrients affect metabolism, weight gain, and obesity associated complications is necessary.

Endoscopically placed stents: a useful alternative for the management of refractory benign cervical esophageal stenosis.

INTRODUCTION: Benign esophageal strictures are relatively frequent and can severely affect the quality of life of a patient. Stenting has been proposed for the treatment of refractory cases. Lesions affecting the cervical esophagus are more difficult to treat, and the placement of stents in this location has traditionally been restricted due to potential adverse events. The aim of this study was to describe the efficacy and safety of endoscopic stenting in the management of refractory benign cervical esophageal strictures (RBCES) in a single-center cohort study. METHODS: We analyzed 12 patients with RBCES (Kochman's criteria) and severe dysphagia. We recorded previous endoscopic treatments, stricture characteristics and demographic data. The two types of stents used were fully covered self-expandable metallic stents (FCSEMS) and uncovered biodegradable stents (BDS). FCSEMS were removed eight weeks after placement, and BDS were followed-up until degradation. We assessed technical and clinical success, rate of stricture recurrence and adverse events. RESULTS: The mean age of participants was 64 years (range 30-85). A total of 23 stents (13 FCSEMS and 10 BDS) were placed in 12 patients (median 1.92, range 1-4). The technical success rate was 96% (22/23 stents). Eight patients (66.6%) maintained adequate oral intake at the end of follow-up (median 33.3 months, range 3-84 months). Migration was recorded in 7/23 stents (30.4%) and epithelial hyperplasia in 4/23 stents (17.4%). No severe adverse events were noted. All patients complained of minor cervical pain after placement that was well controlled with mild analgesia. CONCLUSIONS: Endoscopic stent therapy seems to be effective and safe in the management of RBCES.

Neurocognitive control in dance perception and performance.

Dance is a rich source of material for researchers interested in the integration of movement and cognition. The multiple aspects of embodied cognition involved in performing and perceiving dance have inspired scientists to use dance as a means for studying motor control, expertise, and action-perception links. The aim of this review is to present basic research on cognitive and neural processes implicated in the execution, expression, and observation of dance, and to bring into relief contemporary issues and open research questions. The review addresses six topics: 1) dancers' exemplary motor control, in terms of postural control, equilibrium maintenance, and stabilization; 2) how dancers' timing and on-line synchronization are influenced by attention demands and motor experience; 3) the critical roles played by sequence learning and memory; 4) how dancers make strategic use of visual and motor imagery; 5) the insights into the neural coupling between action and perception yielded through exploration of the brain architecture mediating dance observation; and 6) a neuroesthetics perspective that sheds new light on the way audiences perceive and evaluate dance expression. Current and emerging issues are presented regarding future directions that will facilitate the ongoing dialog between science and dance.

Influencia del tratamiento del hepatocarcinoma antes del trasplante hepático en la recurrencia tumoral y supervivencia postrasplante / Influence of treatment of hepatocellular carcinoma before liver transplantation on postransplant tumor recurrence and survival

ObjetivosEvaluar la efectividad del tratamiento del carcinoma hepatocelular (CHC) previo al trasplante hepático (TH) y su influencia sobre la supervivencia y recurrencia tumoral en pacientes trasplantados con CHC.Pacientes y métodosSe incluyeron 67 pacientes trasplantados con diagnóstico preoperatorio de CHC y confirmación en el explante entre enero del año 2000 y octubre del año 2007. Se realizó tratamiento pretrasplante en 46 pacientes (68,7%) (18 radiofrecuencia, 31 quimioembolización transarterial y 2 alcoholización).ResultadosLa mediana de tiempo entre la inclusión en lista y el TH fue de 4 meses, y fue similar en pacientes tratados y no tratados. El tiempo entre la realización del tratamiento y el TH fue menor de 6 meses en el 65,2%. Los pacientes tratados presentaban mejor función hepática (Child A: el 52,2 vs. el 19%; Child B: el 39,1 vs. el 33,3%; Child C: el 8,7 vs. el 47,6%; p=0,001) y una mayor proporción de tamaño tumoral total >3cm (59,1 vs. 30%; p=0,031). Se confirmó necrosis total del CHC en el 26,1% de los pacientes sin diferencias en el grado de necrosis según el tipo de tratamiento o tamaño tumoral. En 6 pacientes (9%) se produjo recurrencia del CHC. La mediana de tiempo entre el TH y la recurrencia fue de 26,5 meses con una supervivencia tras ésta de 6,6 meses. La supervivencia global fue del 83,5, el 69,9 y el 59,5% y la supervivencia libre de recurrencia tumoral fue del 83,5, el 68,3 y el 58% a 1, 3 y 5 años, respectivamente. El haber recibido tratamiento previo no influyó en la probabilidad de recurrencia o en la supervivencia. Asimismo, el grado de necrosis tampoco se relacionó con la supervivencia o la frecuencia de recurrencia.ConclusiónLa realización de tratamiento del CHC previo al TH en pacientes con un período en lista de espera menor de 6 meses no parece influir en la supervivencia o en la prevención de la recurrencia tumoral postrasplante (AU)

ObjectivesTo evaluate the effectiveness of treatment of hepatocellular carcinoma (HCC) before liver transplantation (LT) and its influence on survival and tumor recurrence in patients transplanted for HCC.Patients and methodsWe included 67 liver transplant patients with a preoperative diagnosis of HCC and pathological confirmation in the native liver between January 2000 and October 2007. Treatment before LT was performed in 46 (68.7%) patients [radiofrequency ablation in 18, transarterial chemoembolization in 31 and percutaneous ethanol injection in two].ResultsThe median time between inclusion on the waiting list and LT was 4 months and was similar in treated and untreated patients. The median time between pre-transplantation locoregional therapy and LT was less than 6 months in 65.2% of the patients. Treated patients had better liver function (Child A 52.2 vs 19%; Child B 39.1 vs 33.3%; Child C 8.7 vs. 47.6%; p=0.001) and a higher proportion of total tumor size >3cm (59.1% vs 30%; p=0.031). Total tumor necrosis was observed in 26.1% of the patients, with no differences according to treatment modality or tumor size. Tumor recurrence occurred in six patients (9%). The median time between LT and tumor recurrence was 26.5 months with a subsequent median survival of 6.6 months. Overall survival was 83.5%, 69.9% and 59.5%, and tumor recurrence-free survival was 83.5%, 68.3% and 58% at 1, 3 and 5 years, respectively. Previous HCC treatment showed no influence on survival or tumor recurrence. Likewise, the grade of tumor necrosis was unrelated to overall survival or the probability of recurrence.ConclusionTreatment of HCC before LT in patients with a waiting list time of less than 6 months does not appear to influence survival or tumor recurrence(AU)

[Influence of treatment of hepatocellular carcinoma before liver transplantation on post transplant tumor recurrence and survival]. / Influencia del tratamiento del hepatocarcinoma antes del trasplante hepático en la recurrencia tumoral y supervivencia postrasplante.

OBJECTIVES: To evaluate the effectiveness of treatment of hepatocellular carcinoma (HCC) before liver transplantation (LT) and its influence on survival and tumor recurrence in patients transplanted for HCC. PATIENTS AND METHODS: We included 67 liver transplant patients with a preoperative diagnosis of HCC and pathological confirmation in the native liver between January 2000 and October 2007. Treatment before LT was performed in 46 (68.7%) patients [radiofrequency ablation in 18, transarterial chemoembolization in 31 and percutaneous ethanol injection in two]. RESULTS: The median time between inclusion on the waiting list and LT was 4 months and was similar in treated and untreated patients. The median time between pre-transplantation locoregional therapy and LT was less than 6 months in 65.2% of the patients. Treated patients had better liver function (Child A 52.2 vs 19%; Child B 39.1 vs 33.3%; Child C 8.7 vs. 47.6%; p=0.001) and a higher proportion of total tumor size > 3 cm (59.1% vs 30%; p=0.031). Total tumor necrosis was observed in 26.1% of the patients, with no differences according to treatment modality or tumor size. Tumor recurrence occurred in six patients (9%). The median time between LT and tumor recurrence was 26.5 months with a subsequent median survival of 6.6 months. Overall survival was 83.5%, 69.9% and 59.5%, and tumor recurrence-free survival was 83.5%, 68.3% and 58% at 1, 3 and 5 years, respectively. Previous HCC treatment showed no influence on survival or tumor recurrence. Likewise, the grade of tumor necrosis was unrelated to overall survival or the probability of recurrence. CONCLUSION: Treatment of HCC before LT in patients with a waiting list time of less than 6 months does not appear to influence survival or tumor recurrence.

Circadian rhythm drives the responsiveness of leptin-mediated hypothalamic pathway of cholecystokinin-8.

Cholecystokinin (CCK) and leptin act coordinately in the brain to regulate food intake and energy balance. Recently we have reported that CCK enhances the permeability of brain barriers to leptin and we have proposed that CCK enhances energy expenditure in rats by activating in the hypothalamus the janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway, which is coupled to leptin receptors. Because plasma leptin concentration follows a circadian rhythm (plasma leptin concentration rise maximal values during the night, after rats start eating), we have hypothesized that the interaction between leptin and CCK should be more intense in animals receiving CCK during the night, i.e., during periods of positive energy balance. In order to further characterize the physiological relevance of the interplay between leptin and CCK we have compared the effect of diurnal vs. nocturnal administration of the C-terminal octapeptide of CCK (CCK-8) on (i) body weight and food intake, and (ii) STAT3 activation, by analyzing phosphorylated STAT3 (pSTAT3) immunostaining within the arcuate nucleus of the hypothalamus. Our results show that CCK decreases body weight and food intake only after p.m. administration. Accordingly pSTAT3 immunostaining within the hypothalamus was more intense in p.m. than in a.m.-treated animals. These data suggest that the effect of CCK on leptin pathways follows a circadian rhythm linked to the energy balance status and gives further support to the interaction between leptin and CCK.

Leptin-mediated hypothalamic pathway of cholecystokinin (CCK-8) to regulate body weight in free-feeding rats.

Regulation of body weight (BW) results from the interplay between different hormonal systems acting at central and peripheral level. This study aims at characterizing the involvement of cholecystokinin (CCK) in BW and energy balance regulation. We have characterized, in free-feeding rats, the effect of CCK-8 on 1) food intake, BW, and adiposity; 2) skeletal muscle metabolism; 3) leptin signaling pathway within the arcuate nucleus of the hypothalamus; and 4) the permeability of brain barriers to leptin. We demonstrate here that CCK-8 acutely decreases BW by a mechanism partially dependent on central leptin pathways, based on the following results: 1) the effect of CCK was less intense in rats lacking functional leptin receptors (Zucker fa/fa), 2) CCK-8 facilitated the uptake of leptin from peripheral circulation to cerebrospinal fluid (CSF), 3) the concentration of leptin in CSF of rats receiving CCK was more elevated in those animals showing higher loss of BW, and 4) CCK activated leptin signaling pathways within the hypothalamus as well as phosphorylation of AMP-activated protein kinase in skeletal muscle. We also suggest that gain of BW may be linked to individual susceptibility to the effect of CCK, because we observed that in animals treated with this hormone, the increase of BW negatively correlated with leptin concentration within the CSF. Our data show that CCK has a negative impact on energy balance and suggest that CCK facilitates the access of leptin to hypothalamic areas, thus allowing leptin to act on hypothalamic targets involved in BW control.