960 resultados para Food-specific satiety


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Delta 9-THC is a component of Cannabis sativa that increases food intake in animals and humans, an effect prevented by selective CB1 receptor antagonists. Cannabidiol (CBD) is another constituent of this plant that promotes several opposite neuropharmacological effects compared to Delta 9-THC. CBD mechanisms of action are still not clear, but under specific experimental conditions it can antagonize the effects of cannabinoid agonists, block the reuptake of anandamide and act as an agonist of 5-HT1A receptors. Since both the cannabinoid and serotoninergic systems have been implicated in food intake control, the aim of the present work was to investigate the effects caused by CBD on hyperphagia induced by agonists of CB1 or 5-HT1A receptors. Fed or fasted Wistar rats received intraperitoneal (i.p.) injections of CBD (1, 10 and 20 mg/kg) and food intake was measured 30 min later for 1 h. Moreover, additional fed or fasted groups received, after pretreatment with CBD (20 mg/kg) or vehicle, i.p. administration of vehicle, a CBI receptor agonist WIN55,212-2 (2 mg/kg) or a 5-HT1A receptor agonist 8-OH-DPAT (1 mg/kg) and were submitted to the food intake test for 1 h. CBD by itself did not change food intake in fed or fasted rats. However, it prevented the hyperphagic effects induced by WIN55,212-2 or 8-OH-DPAT. These results show that CBD can interfere with food intake changes induced by a CB1 or 5-HT1A receptor agonist, suggesting that its role as a possible food intake regulator should be further investigate. (C) 2011 Elsevier Inc. All rights reserved.

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Cholecystokinin (CCK) provides a meal-related signal that activates brainstem neurons, which have reciprocal interconnections with the hypothalamic paraventricular nucleus. Neurons that express corticotrophin-releasing factor (CRF) in the hypothalamus possess anorexigenic effects and are activated during endotoxaemia. This study investigated the effects of CCK(1) receptor blockade on lipopolysaccharide (LPS)-induced hypophagia and hypothalamic CRF neuronal activation. Male Wistar rats were pretreated with a specific CCK(1) receptor antagonist (devazepide; 1 mg kg(-1); I.P.) or vehicle; 30 min later they received LPS (100 mu g kg(-1); I.P.) or saline injection. Food intake, corticosterone responses and Fos-CRF and Fos-alpha-melanocyte-stimulating hormone (alpha-MSH) immunoreactivity in the hypothalamus and Fos-tyrosine hydroxylase immunoreactivity in the nucleus of the solitary tract (NTS) were evaluated. In comparison with saline treatment, LPS administration decreased food intake and increased plasma corticosterone levels, as well as the number of Fos-CRF and Fos-tyrosine hydroxylase double-labelled neurons in vehicle-pretreated rats; no change in Fos-alpha-MSH immunoreactivity was observed after LPS injection. In saline-treated animals, devazepide pretreatment increased food intake, but it did not modify other parameters compared with vehicle-pretreated rats. Devazepide pretreatment partly reversed LPS-induced hypophagia and Fos-CRF and brainstem neuronal activation. Devazepide did not modify the corticosterone and Fos-alpha-MSH responses in rats treated with LPS. In conclusion, the present data suggest that LPS-induced hypophagia is mediated at least in part by CCK effects, via CCK(1) receptor, on NTS and hypothalamic CRF neurons.

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Background/Objectives: Reduced food intake, appetite loss and alteration of ghrelin and PYY(3-36) secretion have been suggested to have a function in the loss of body weight commonly observed after gastrectomy. The objective of this study was to investigate the circulating concentrations of ghrelin and PYY(3-36) and their relationships with food intake, appetite and resting energy expenditure (REE) after gastrectomy plus vagotomy. Subjects/Methods: Seven patients with total gastrectomy (TG), 14 with partial gastrectomy (PG) and 10 healthy controls were studied. Habitual food intake and REE was assessed; fasting and postprandial plasma total ghrelin, PYY(3-36) concentrations and appetite ratings were determined after ingestion of a liquid test meal. Results: Differently from PG and controls, fasting ghrelin correlated with REE, and a higher energy intake was observed in the TG group. Fasting plasma ghrelin concentrations were lower in TG compared with controls, and no ghrelin response to the meal was observed in either PG or TG. Fasting plasma PYY(3-36) concentrations were not different among the groups. There was an early and exaggerated postprandial rise in PYY(3-36) levels in both PG and TG groups, but not in controls. No effect of ghrelin or PYY(3-36) concentrations was observed on hunger, prospective consumption or fullness ratings. Conclusions: Total ghrelin and PYY(3-36) do not seem to be involved with appetite or energy intake regulation after gastrectomy plus vagotomy. Ghrelin secreted by sources other than stomach is likely to have a function in the long-term regulation of body weight after TG. European Journal of Clinical Nutrition (2010) 64, 845-852; doi: 10.1038/ejcn.2010.88; published online 19 May 2010

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Modulation of salt appetite involves interactions between the circumventricular organs (CVOs) receptive areas and inhibitory hindbrain serotonergic circuits. Recent studies provide support to the idea that the serotonin action in the lateral parabrachial nucleus (LPBN) plays an important inhibitory role in the modulation of sodium appetite. The aim of the present work was to identify the specific groups of neurons projecting to the LPBN that are activated in the course of sodium appetite regulation, and to analyze the associated endocrine response, specifically oxytocin (OT) and atrial natriuretic peptide (ANP) plasma release, since both hormones have been implicated in the regulatory response to fluid reestablishment. For this purpose we combined the detection of a retrograde transported dye, Fluorogold (FG) injected into the LPBN with the analysis of the Fos immunocytochemistry brain pattern after sodium intake induced by sodium depletion. We analyzed the Fos-FG immunoreactivity after sodium ingestion induced by peritoneal dialysis (PD). We also determined OT and ANP plasma concentration by radioimmunoassay (RIE) before and after sodium intake stimulated by PD. The present study identifies specific groups of neurons along the paraventricular nucleus, central extended amygdala, insular cortex, dorsal raphe nucleus, nucleus of the solitary tract and the CVOs that are activated during the modulation of sodium appetite and have direct connections with the LPBN. It also shows that OT and ANP are released during the course of sodium satiety and fluid reestablishment. The result of this brain network activity may enable appropriate responses that re-establish the body fluid balance after induced sodium consumption. (C) 2009 Elsevier Inc. All rights reserved.

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Bird sex determination using molecular methods has proved to be a valuable tool in different studies. Although it is possible to sex most birds by coupling the CHD assay with others available methods, no sex-determining gene like SRY in mammalians has been identified in birds. The male hypermethylated (MHM) region on the Z chromosome has been found to be hypermethylated in males and hypomethylated in females in birds of the order Galliformes. We analyzed the DNA from feathers of 50 adult chickens to verify the methylation pattern of the MHM region by PCR and the restriction enzyme HpaII (a method named MHM assay). The results, visualized in agarose gel, were compared with PCR amplification of the CHD-Z and CHD-W genes (polyacrylamide gel) and with the birds` phenotype. All males (25) showed hypermethylation of the MHM region, and all females (25) showed hypomethylation. The sexing by MHM assay was in according with phenotype and CHD sexing. To our knowledge, this is the first study that uses the MHM region for sexing birds. Although the real role of the MHM region in the sex determination is still unclear, this could be a universal marker for sexing birds and may be involved in sex determination by its influence on transcriptional processes. The MHM assay could be a good alternative for CHD assay in developmental studies.

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This paper reports on the outcomes of the first stage of a longitudinal study that focused on the transformational change process being undertaken within the Supply Chain and Operations Area of a major Australian food manufacturing company. Organizational learning is an essential prerequisite for any successful change process and an organization's ability to learn is dependent on the existence of an environment within the organization that nurtures learning and the presence of key enablers that facilitate the learning process. An organization's capacity to learn can be enhanced through its ability to form and sustain collaborative relationships with its chain partners. The results show that an environment that supports organizational learning is being developed through consultative leadership and the empowerment of individuals within a culture that supports innovation and cross-functional teamwork but demands responsibility and accountability. The impact of these changes within the Supply Chain and Operations Area is evident in the significant improvement in the Area's productivity and efficiency levels over the past twelve months. The company's endeavours to engage its major supply chain partners in the learning process have been limited by the turmoil within the company. However the company has involved its supply chain partners in a series of mutually beneficial projects that have improved communication and built trust thereby laying the foundations for more collaborative chain relationships.

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Topoisomerases are ubiquitous nuclear enzymes that regulate DNA structure in eukaryotic cells. The role of topoisomerase III beta, the newest member of the topoisomerase family, in the clinical outcome of breast cancer is still poorly understood. This study aims to investigate the immunoexpression of topoisomerase III beta in breast cancer and its relationships with clinicopathologic features and immunohistochemical markers of prognostic significance in breast pathology. Using tissue microarrays containing 171 cases of primary invasive breast cancer, we analyzed the immunoexpression of topoisomerase III beta, estrogen receptor, progesterone receptor, HER-2, BRCA-1, p53, and Ki67. Immunostaining for topoisomerase III beta was found in 33.9% of breast carcinomas, and immunopositivity was correlated with distant metastasis (P = .036) and death (P = .006). Decreased expression of topoisomerase III beta correlated with low expression of Ki67 (P < .001) and negativity for HER-2 (P < .001), BRCA-1 (P = .001), and p53 (P < .001). In the multivariate analysis, topoisomerase Hip expression was a significant predictor of survival (hazard ratio, 3.006 [95% confidence interval, 1.582-5.715]; P = .001). In conclusion, topoisomerase III beta expression can be a useful marker in assessing the prognosis of patients with breast cancer and is an independent predictor of survival. (C) 2010 Elsevier Inc. All rights reserved.

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OBJECTIVE: HIV transmission has been associated with offering a child food prechewed by an HIV-infected caregiver. We assessed awareness of prechewing and oral prewarming of food by an adult before offering it to a child among HIV-infected pregnant women and clinical investigators in 3 Latin American countries. METHODS: HIV-infected pregnant women at 12 sites (Eunice Kennedy Shriver National Institute of Child Health and Human Development International Site Development Initiative Perinatal Longitudinal Study in Latin American Countries, a prospective cohort trial) in Argentina, Brazil, and Peru were administered a screening survey about prechewing/prewarming of infant foods and cautioned against these feeding practices. Survey responses were analyzed, overall, and stratified according to country. RESULTS: Of the 401 HIV-infected pregnant women interviewed, 34% had heard about prechewing (50% from Argentina, 32% from Brazil, and 36% from Peru), 23% knew someone who prechewed food for infants, and 4% had prechewed food in the past. Seventeen percent had heard about oral prewarming of food, 13% knew someone who prewarmed food for infants, and 3% had prewarmed food for an infant in the past. Women who reported knowing someone who prechewed were more likely to also know someone who prewarmed food (P < .0001). Few site investigators anticipated that their patients would be aware of these practices. CONCLUSIONS: Prechewing food, a potential risk factor for HIV transmission, and orally prewarming food, which has not been associated with HIV transmission but might expose a child to blood from an HIV-infected adult, are not uncommon practices in Latin America. Both practices should be further investigated. Site investigator responses underscore that health care providers could be missing information about cultural practices that patients may not report unless specifically asked. Pediatrics 2011;127:e1206-e1211

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Adenosine deaminase (ADA) deficiency is a disorder of the purine metabolism leading to combined immunodeficiency and systemic alterations, including skeletal abnormalities. We report that ADA deficiency in mice causes a specific bone phenotype characterized by alterations of structural properties and impaired mechanical competence. These alterations are the combined result of an imbalanced receptor activator of nuclear factor-kappa B ligand (RANKL)/osteoprotegerin axis, causing decreased osteoclastogenesis and an intrinsic defect of osteoblast function with subsequent low bone formation. In vitro, osteoblasts lacking ADA displayed an altered transcriptional profile and growth reduction. Furthermore, the bone marrow microenvironment of ADA-deficient mice showed a reduced capacity to support in vitro and in vivo hematopoiesis. Treatment of ADA-deficient neonatal mice with enzyme replacement therapy, bone marrow transplantation, or gene therapy resulted in full recovery of the altered bone parameters. Remarkably, untreated ADA-severe combined immunodeficiency patients showed a similar imbalance in RANKL/osteoprotegerin levels alongside severe growth retardation. Gene therapy with ADA-transduced hematopoietic stem cells increased serum RANKL levels and children`s growth. Our results indicate that the ADA metabolism represents a crucial modulatory factor of bone cell activities and remodeling. The trials were registered at www.clinicaltrials.gov as #NCT00598481 and #NCT00599781. (Blood. 2009; 114: 3216-3226)

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Background The pattern of associations and the attributable fractions (AF) of atopic conditions due to specific sensitizations vary between countries. Objective To assess the level of associations and AF between sensitization to five allergens and atopic conditions in two settings. Methods We studied 2063 Brazilians and 1231 Chileans of both sexes using representative samples selected at birth in the 1970s. Information on asthma and rhinitis was based on the European Community Respiratory Health Survey questionnaire. We assessed bronchial hyperresponsiveness (BHR) to methacholine and sensitization to Dermatophagoides pteronyssinus, cat, dog, grass blend and Alternaria alternata. Results The prevalence of sensitization to one or more allergens was 50% in Brazilians and 22% in Chileans. The level of associations varied according to the outcome used. Strong associations between sensitization and asthma, defined as wheeze or awakening with breathlessness at night and positive BHR, were found for each of the five allergens in Chileans [varying from odds ratio (OR) 3.24, 95% confidence interval (CI) 1.47, 7.15 for D. pteronyssinus to 8.44, 95% CI 3.82, 18.66 for cat], whereas the level of associations was restricted to D. pteronyssinus, cat and dog in Brazilians and was somewhat weaker (highest OR 3.90, 95% CI 2.80-5.44). The AF of sensitization on asthma was 54% in Brazil and 44% in Chile. D. pteronyssinus and cat made an independent contribution to asthma in the two samples. The patterns of associations between sensitization and rhino-conjunctivitis were similar to those for asthma. Conclusion The associations between sensitization, and asthma and rhinitis were high in Chile and moderately high in Brazil, but the AF were higher in Brazil, reflecting a higher prevalence of sensitization. In Brazil, dust mite had the greatest impact on atopic conditions while in Chile several allergens had an impact. Sensitization is as serious a problem in Chile and Brazil as in developed countries.

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Objective: This study aimed to assess the relative validity of a food frequency questionnaire.(FFQ), previously validated to measure usual intakes in adults, for measuring dietary intakes in children 5 to 10 y of age. Methods: Dietary intakes were measured using an FFQ and a 3-d dietary record. Healthy children, 5 to 10 y old (n = 151), were recruited from public schools and asked to answer the questions in the FFQ and to provide non-consecutive 3-d dietary records based on reported estimated portion sizes. Paired sample t tests and Pearson`s correlation coefficients were conducted to determine whether the two instruments reported similar values for energy and nutrients. The agreement of quartile categorization between the two instruments was also examined. Results: Estimated energy and nutrient intakes derived from the FFQ were significantly higher than those derived from 3-d dietary records. As expected, Pearson`s correlations increased after adjusting for residual measurement error, presumably due to exclusion of the high within-person variability in intake of these nutrients. Moderate to high (r > 0.50) correlation coefficients were verified for some nutrients such as calcium, folate, vitamin 132, vitamin A, and vitamin C. Conclusion: This FFQ, originally developed for use in adults, appears to overestimate usual energy and nutrient intakes in children 5 to 10 y of age. Further work is necessary to conduct a calibration study to establish adequate portion sizes before instrument adoption in this population. (c) 2008 Elsevier Inc. All rights reserved.