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Cowley MA, Smart JL, Rubinstein M, Cerdán MG, Diano S, Horvath TL, Cone RD, Low MJ. Leptin activates anorexigenic POMC neurons through a neural network in the arcuate nucleus. Nature 2001; 411:480-4. [PMID: 11373681 DOI: 10.1038/35078085] [Citation(s) in RCA: 1714] [Impact Index Per Article: 71.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The administration of leptin to leptin-deficient humans, and the analogous Lepob/Lepob mice, effectively reduces hyperphagia and obesity. But common obesity is associated with elevated leptin, which suggests that obese humans are resistant to this adipocyte hormone. In addition to regulating long-term energy balance, leptin also rapidly affects neuronal activity. Proopiomelanocortin (POMC) and neuropeptide-Y types of neurons in the arcuate nucleus of the hypothalamus are both principal sites of leptin receptor expression and the source of potent neuropeptide modulators, melanocortins and neuropeptide Y, which exert opposing effects on feeding and metabolism. These neurons are therefore ideal for characterizing leptin action and the mechanism of leptin resistance; however, their diffuse distribution makes them difficult to study. Here we report electrophysiological recordings on POMC neurons, which we identified by targeted expression of green fluorescent protein in transgenic mice. Leptin increases the frequency of action potentials in the anorexigenic POMC neurons by two mechanisms: depolarization through a nonspecific cation channel; and reduced inhibition by local orexigenic neuropeptide-Y/GABA (gamma-aminobutyric acid) neurons. Furthermore, we show that melanocortin peptides have an autoinhibitory effect on this circuit. On the basis of our results, we propose an integrated model of leptin action and neuronal architecture in the arcuate nucleus of the hypothalamus.
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Research Support, U.S. Gov't, P.H.S. |
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1714 |
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Sarraf P, Frederich RC, Turner EM, Ma G, Jaskowiak NT, Rivet DJ, Flier JS, Lowell BB, Fraker DL, Alexander HR. Multiple cytokines and acute inflammation raise mouse leptin levels: potential role in inflammatory anorexia. J Exp Med 1997; 185:171-5. [PMID: 8996253 PMCID: PMC2196098 DOI: 10.1084/jem.185.1.171] [Citation(s) in RCA: 556] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/1996] [Revised: 10/22/1996] [Indexed: 02/03/2023] Open
Abstract
Several inflammatory cytokines, most notably tumor necrosis factor (TNF) and IL-1, induce anorexia and loss of lean body mass, common manifestations of acute and chronic inflammatory conditions. In C57BL/6 female mice, the administration of TNF, IL-1, and, to a lesser extent, leukemia inhibitory factor (LIF), produced a prompt and dose-dependent increase in serum leptin levels and leptin mRNA expression in fat. IL-10, IL-4, ciliary neurotrophic factor, and IL-2, cytokines not known to induce anorexia or decrease food intake, had no effect on leptin gene expression or serum leptin levels. After administration of Escherichia coli lipopolysaccharide (LPS), leptin gene expression and leptin levels were increased. These findings suggest that leptin levels may be one mechanism by which anorexia is induced during acute inflammatory conditions.
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Abstract
The common cold and influenza (flu) are the most common syndromes of infection in human beings. These diseases are diagnosed on symptomatology, and treatments are mainly symptomatic, yet our understanding of the mechanisms that generate the familiar symptoms is poor compared with the amount of knowledge available on the molecular biology of the viruses involved. New knowledge of the effects of cytokines in human beings now helps to explain some of the symptoms of colds and flu that were previously in the realm of folklore rather than medicine-eg, fever, anorexia, malaise, chilliness, headache, and muscle aches and pains. The mechanisms of symptoms of sore throat, rhinorrhoea, sneezing, nasal congestion, cough, watery eyes, and sinus pain are discussed, since these mechanisms are not dealt with in any detail in standard medical textbooks.
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Review |
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Abstract
Elactocin is a novel anti-tumour antibiotic which has potent activity in vitro against a range of tumours. This phase I trial of elactocin identified the dose-limiting toxicity as profound anorexia and malaise. The schedules used included 1 h infusion 3 weekly, 24 h infusion 3 weekly, 1 h infusion daily x 5 (3 weekly), 1 h infusion weekly and finally continuous 5 day intravenous infusion. On all these schedules dose-limiting toxicity was the same and as no partial or complete responses were identified, we do not recommend that further trials of elactocin are performed.
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Treasure J, Murphy T, Szmukler G, Todd G, Gavan K, Joyce J. The experience of caregiving for severe mental illness: a comparison between anorexia nervosa and psychosis. Soc Psychiatry Psychiatr Epidemiol 2001; 36:343-7. [PMID: 11606003 DOI: 10.1007/s001270170039] [Citation(s) in RCA: 164] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The aim of this study was to examine the experience of care giving for people with anorexia nervosa and to compare it with the experiences of those people who care for a person with a psychotic illness. METHOD Carers (parents, siblings and husbands) of people with eating disorders who had experienced an episode of inpatient care for anorexia nervosa (n=71) were given the General Health Questionnaire and the Experience of Caregiving Inventory. A sample of carers (N=68) of people with a psychotic illness from the community were used as a comparison group. A subgroup of the carers (n=20) of people with anorexia nervosa were asked to write about their experiences. RESULTS The clinical samples had a similar duration of illness, but the patients with anorexia nervosa were significantly younger and a larger proportion were living at home. The general health scores were significantly higher in the carers of anorexia nervosa and they experienced higher levels of difficulties in most areas of caregiving. A variety of variables from the Caregiving Inventory contributed to the level of psychological distress, accounting for 36% of the variance. The themes of guilt and shame were additional dimensions that were addressed in the letters. CONCLUSIONS Carers of people with anorexia nervosa are challenged by the difficulties their role produces.
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Comparative Study |
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Groves HT, Higham SL, Moffatt MF, Cox MJ, Tregoning JS. Respiratory Viral Infection Alters the Gut Microbiota by Inducing Inappetence. mBio 2020; 11:e03236-19. [PMID: 32071269 PMCID: PMC7029140 DOI: 10.1128/mbio.03236-19] [Citation(s) in RCA: 130] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 01/09/2020] [Indexed: 02/07/2023] Open
Abstract
Respiratory viral infections are extremely common, but their impacts on the composition and function of the gut microbiota are poorly understood. We previously observed a significant change in the gut microbiota after viral lung infection. Here, we show that weight loss during respiratory syncytial virus (RSV) or influenza virus infection was due to decreased food consumption, and that the fasting of mice altered gut microbiota composition independently of infection. While the acute phase tumor necrosis factor alpha (TNF-α) response drove early weight loss and inappetence during RSV infection, this was not sufficient to induce changes in the gut microbiota. However, the depletion of CD8+ cells increased food intake and prevented weight loss, resulting in a reversal of the gut microbiota changes normally observed during RSV infection. Viral infection also led to changes in the fecal gut metabolome, with a significant shift in lipid metabolism. Sphingolipids, polyunsaturated fatty acids (PUFAs), and the short-chain fatty acid (SCFA) valerate were all increased in abundance in the fecal metabolome following RSV infection. Whether this and the impact of infection-induced anorexia on the gut microbiota are part of a protective anti-inflammatory response during respiratory viral infections remains to be determined.IMPORTANCE The gut microbiota has an important role in health and disease: gut bacteria can generate metabolites that alter the function of immune cells systemically. Understanding the factors that can lead to changes in the gut microbiome may help to inform therapeutic interventions. This is the first study to systematically dissect the pathway of events from viral lung infection to changes in gut microbiota. We show that the cellular immune response to viral lung infection induces inappetence, which in turn alters the gut microbiome and metabolome. Strikingly, there was an increase in lipids that have been associated with the resolution of disease. This opens up new paths of investigation: first, what is the (presumably secreted) factor made by the T cells that can induce inappetence? Second, is inappetence an adaptation that accelerates recovery from infection, and if so, does the microbiome play a role in this?
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Agnello D, Wang H, Yang H, Tracey KJ, Ghezzi P. HMGB-1, a DNA-binding protein with cytokine activity, induces brain TNF and IL-6 production, and mediates anorexia and taste aversion. Cytokine 2002; 18:231-6. [PMID: 12126646 DOI: 10.1006/cyto.2002.0890] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
High-mobility group protein-1 (HMG-1 also termed HMGB-1), a DNA-binding protein, regulates gene transcription and stabilizes nucleosome formation. HMG-1 was recently implicated as a cytokine, because it is a late-acting mediator of endotoxin lethality that induces the release of pro-inflammatory cytokines from monocytes. Here it is shown that administration of HMG-1 into the cerebral ventricles decreases food intake (food intake=4.6g/mouse in controls vs 1.6g/mouse after 1 microg HMG-1 i.c.v.; P <0.05). Intracerebroventricular HMG-1 induced an increased in TNF and IL-6 expression in the brain, and mediated taste aversion with potencies equivalent to LPS. In a model of endotoxemia, passive immunization with anti-HMG-1 antibodies attenuated the development of hypophagia, indicating that HMG-1 is a mediator of sickness behaviour associated with endotoxemia.
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Abstract
Various categories of cytokines participate in the control of feeding, including interleukin-1 and -6 and other activators of gp 130, leptin (ob protein), interleukin-8 and other chemokines, tumor necrosis factor-alpha, and interferon-alpha. These feeding-inhibitory cytokines may play a role in the regulation of food intake during physiological (eg a role proposed for leptin) and pathophysiological (eg proinflammatory cytokines) conditions. Data show that various cytokines participate in acute and chronic disease-associated anorexia such as during infection, inflammation or malignancy. Food intake suppression (reported as anorexia) is also a common central manifestation observed during cytokine immunotherapy in humans. The concept of local production of various cytokines within specific brain regions in response to peripheral challenges and pathophysiological processes has broad implications for the interpretation of brain cytokines as mediators or participants in CNS modulation of feeding and anorexia.
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Review |
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100 |
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Brede J, Babb C, Jones C, Elliott M, Zanker C, Tchanturia K, Serpell L, Fox J, Mandy W. "For Me, the Anorexia is Just a Symptom, and the Cause is the Autism": Investigating Restrictive Eating Disorders in Autistic Women. J Autism Dev Disord 2020; 50:4280-4296. [PMID: 32274604 PMCID: PMC7677288 DOI: 10.1007/s10803-020-04479-3] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Autistic women are overrepresented among people in treatment for Anorexia Nervosa (AN). The current study aimed to: (1) better understand how AN develops and persists in autistic individuals from the perspective of autistic women, parents and healthcare professionals; (2) derive a theoretical model of restrictive eating difficulties in autism. We conducted 44 semi-structured interviews and used Thematic Analysis to identify patterns of meaning across the data. Themes related to sensory sensitivities, social interaction and relationships, sense of self and identity, difficulties with emotions, thinking styles, and a need for control and predictability. We developed a model of potential autism-specific mechanisms underlying restrictive eating difficulties. This study generated novel insights, which have the potential to inform treatment adaptations following empirical testing.
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research-article |
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Ritz BW, Aktan I, Nogusa S, Gardner EM. Energy restriction impairs natural killer cell function and increases the severity of influenza infection in young adult male C57BL/6 mice. J Nutr 2008; 138:2269-75. [PMID: 18936230 PMCID: PMC2635521 DOI: 10.3945/jn.108.093633] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Revised: 06/27/2008] [Accepted: 08/15/2008] [Indexed: 11/14/2022] Open
Abstract
Energy restriction (ER) without malnutrition extends lifespan in mice and postpones age-related changes in immunity. However, we have previously shown that aged (22 mo old) ER mice exhibit increased mortality, impaired viral clearance, and reduced natural killer (NK) cell cytotoxicity following influenza infection compared with aged mice that consumed food ad libitum (AL). To determine whether the detrimental effects of ER in response to influenza infection occur independently of advanced age, young adult (6 mo) male C57BL/6 mice consuming an AL or ER diet were infected with influenza A virus (H1N1, PR8). Young adult ER mice exhibited increased mortality (P < 0.05) and weight loss (P < 0.01) in response to infection. ER mice exhibited decreased total (P < 0.001) and NK1.1+ lymphocytes (P < 0.05) in lung and reduced influenza-induced NK cell cytotoxicity in both lung (P < 0.01) and spleen (P < 0.05). Importantly, the mRNA expression of interferon (IFN)alpha/beta (P < 0.05) was also reduced in the lungs of ER mice in response to infection, and in vitro stimulation of NK cells from ER mice with type I IFN resulted in cytotoxicity comparable to that in NK cells from AL mice. In contrast, NK cell activation was enhanced in ER mice, determined as an increase in the percentage of NK cells expressing B220 (P < 0.001) and increased intracellular production of IFNgamma (P < 0.01). These data describe an age-independent and detrimental effect of ER on the innate immune response to influenza infection and suggest that a decrease in NK cell number and alterations in the NK cell-activating environment may contribute to decreased innate immunity in ER mice.
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Research Support, N.I.H., Extramural |
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Scarpi E, Maltoni M, Miceli R, Mariani L, Caraceni A, Amadori D, Nanni O. Survival prediction for terminally ill cancer patients: revision of the palliative prognostic score with incorporation of delirium. Oncologist 2011; 16:1793-9. [PMID: 22042788 DOI: 10.1634/theoncologist.2011-0130] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
PURPOSE An existing and validated palliative prognostic (PaP) score predicts survival in terminally ill cancer patients based on dyspnea, anorexia, Karnofsky performance status score, clinical prediction of survival, total WBC, and lymphocyte percentage. The PaP score assigns patients to three different risk groups according to a 30-day survival probability--group A, >70%; group B, 30%-70%; group C, <30%. The impact of delirium is known but was not incorporated into the PaP score. MATERIALS AND METHODS Our aim was to incorporate information on delirium into the PaP score based on a retrospective series of 361 terminally ill cancer patients. We followed the approach of "validation by calibration," proposed by van Houwelingen and later adapted by Miceli for achieving score revision with inclusion of a new variable. The discriminating performance of the scores was estimated using the K statistic. RESULTS The prognostic contribution of delirium was confirmed as statistically significant (p < .001) and the variable was accordingly incorporated into the PaP score (D-PaP score). Following this revision, 30-day survival estimates in groups A, B, and C were 83%, 50%, and 9% for the D-PaP score and 87%, 51%, and 16% for the PaP score, respectively. The overall performance of the D-PaP score was better than that of the PaP score. CONCLUSION The revision of the PaP score was carried out by modifying the cutoff values used for prognostic grouping without, however, affecting the partial scores of the original tool. The performance of the D-PaP score was better than that of the PaP score and its key feature of simplicity was maintained.
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Validation Study |
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73 |
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Hoyle B, Yunus M, Chen LC. Breast-feeding and food intake among children with acute diarrheal disease. Am J Clin Nutr 1980; 33:2365-71. [PMID: 7435417 DOI: 10.1093/ajcn/33.11.2365] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
To quantitate reduced food intake during diarrhea and to assess possible means of promoting such intake, the 24-hr food and breast milk intakes of 41 children 6 to 35 months divided into three groups were measured. The energy and protein intake of 15 children hospitalized with acute watery diarrhea averaged 75 kcal/kg and 0.96 g/kg, respectively. The energy and protein consumption of another group of 15 children with diarrhea whose mothers received intensive education to promote food intake during hospitalization averaged 60.9 kcal/kg and 0.70 g/kg, respectively. These intake levels were significantly lower than 129.9 kcal/kg and 1.89 g/kg observed among healthy control children. These results suggest that child anorexia may be an important cause of reduced food intake during diarrhea. Anorexia was not overcome with intensive educational efforts. Breast milk was found to be important nutrient source with breast-fed children better protected against reduced intake during diarrhea.
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68 |
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Anderberg RH, Richard JE, Eerola K, López-Ferreras L, Banke E, Hansson C, Nissbrandt H, Berqquist F, Gribble FM, Reimann F, Wernstedt Asterholm I, Lamy CM, Skibicka KP. Glucagon-Like Peptide 1 and Its Analogs Act in the Dorsal Raphe and Modulate Central Serotonin to Reduce Appetite and Body Weight. Diabetes 2017; 66:1062-1073. [PMID: 28057699 PMCID: PMC6237271 DOI: 10.2337/db16-0755] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 01/02/2017] [Indexed: 12/13/2022]
Abstract
Glucagon-like peptide 1 (GLP-1) and serotonin play critical roles in energy balance regulation. Both systems are exploited clinically as antiobesity strategies. Surprisingly, whether they interact in order to regulate energy balance is poorly understood. Here we investigated mechanisms by which GLP-1 and serotonin interact at the level of the central nervous system. Serotonin depletion impaired the ability of exendin-4, a clinically used GLP-1 analog, to reduce body weight in rats, suggesting that serotonin is a critical mediator of the energy balance impact of GLP-1 receptor (GLP-1R) activation. Serotonin turnover and expression of 5-hydroxytryptamine (5-HT) 2A (5-HT2A) and 5-HT2C serotonin receptors in the hypothalamus were altered by GLP-1R activation. We demonstrate that the 5-HT2A, but surprisingly not the 5-HT2C, receptor is critical for weight loss, anorexia, and fat mass reduction induced by central GLP-1R activation. Importantly, central 5-HT2A receptors are also required for peripherally injected liraglutide to reduce feeding and weight. Dorsal raphe (DR) harbors cell bodies of serotonin-producing neurons that supply serotonin to the hypothalamic nuclei. We show that GLP-1R stimulation in DR is sufficient to induce hypophagia and increase the electrical activity of the DR serotonin neurons. Finally, our results disassociate brain metabolic and emotionality pathways impacted by GLP-1R activation. This study identifies serotonin as a new critical neural substrate for GLP-1 impact on energy homeostasis and expands the current map of brain areas impacted by GLP-1R activation.
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research-article |
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Abstract
Appetite and food intake decrease with normal ageing, predisposing to the development of under-nutrition. Under-nutrition is common in older people and has been implicated in the development and progression of chronic diseases commonly affecting the elderly, as well as in increasing mortality. An understanding of the factors that contribute to the physiological and pathological declines in food intake in older people is likely to aid in the development of effective forms of prevention and treatment. Ageing affects many of the endocrine factors involved in the control of appetite and feeding but few studies have been performed in humans to clarify these changes. Possible hormonal causes of the anorexia of ageing include increased activity of cholecystokinin, leptin and various cytokines and reduced activity of ghrelin and testosterone.
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Review |
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66 |
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Poulia KA, Sarantis P, Antoniadou D, Koustas E, Papadimitropoulou A, Papavassiliou AG, Karamouzis MV. Pancreatic Cancer and Cachexia-Metabolic Mechanisms and Novel Insights. Nutrients 2020; 12:1543. [PMID: 32466362 PMCID: PMC7352917 DOI: 10.3390/nu12061543] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 05/15/2020] [Accepted: 05/25/2020] [Indexed: 02/06/2023] Open
Abstract
Cachexia is a major characteristic of multiple non-malignant diseases, advanced and metastatic cancers and it is highly prevalent in pancreatic cancer, affecting almost 70-80% of the patients. Cancer cachexia is a multifactorial condition accompanied by compromised appetite and changes in body composition, i.e., loss of fat. It is associated with lower effectiveness of treatment, compromised quality of life, and higher mortality. Understanding the complex pathways underlying the pathophysiology of cancer cachexia, new therapeutic targets will be unraveled. The interplay between tumor and host factors, such as cytokines, holds a central role in cachexia pathophysiology. Cytokines are possibly responsible for anorexia, hypermetabolism, muscle proteolysis, and apoptosis. In particular, cachexia in pancreatic cancer might be the result of the surgical removal of pancreas parts. In recent years, many studies have been carried out to identify an effective treatment algorithm for cachexia. Choosing the most appropriate treatment, the clinical effect and the risk of adverse effects should be taken under consideration. The purpose of this review is to highlight the pathophysiological mechanisms as well as the current ways of cachexia treatment in the pharmaceutical and the nutrition field.
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Review |
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66 |
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Cooper SJ. Palatability-dependent appetite and benzodiazepines: new directions from the pharmacology of GABA(A) receptor subtypes. Appetite 2005; 44:133-50. [PMID: 15808888 DOI: 10.1016/j.appet.2005.01.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2004] [Revised: 12/08/2004] [Accepted: 01/20/2005] [Indexed: 01/22/2023]
Abstract
This paper updates an early review on benzodiazepine-enhanced food intake, published in the first issue of Appetite, and describes the considerable advances since then in the pharmacology of benzodiazepines, their sites and mechanisms of action, and in understanding the psychological processes leading to the increase in food consumption. A great diversity of benzodiazepine receptor ligands have been developed, many of which affect food intake. Agonists can be divided into full agonists (which produce the full spectrum of benzodiazepine effects) and partial agonists (which are more selective in their effects). In addition, inverse agonists have been identified, with high affinity for benzodiazepine receptors but having negative efficacy: these drugs exhibit anorectic properties. Benzodiazepine receptors are part of GABA(A) receptor complexes, and ligands thereby modulate inhibitory neurotransmission in the brain. Molecular approaches have identified a palette of receptor subunits from which GABA(A) receptors are assembled. In all likelihood, benzodiazepine-induced hyperphagia is mediated by the alpha2/alpha3 subtype not the alpha1 subtype. Novel alpha2/alpha3 selective compounds will test this hypothesis. A probable site of action in the caudal brainstem for benzodiazepines is the parabrachial nucleus. Behavioural evidence strongly indicates that a primary action of benzodiazepines is to enhance the positive hedonic evaluation (palatability) of tastes and foodstuffs. This generates the increased food intake and instrumental responding for food rewards. Therapeutic applications may derive from the actions of benzodiazepine agonists and inverse agonists on food procurement and ingestion.
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Review |
20 |
61 |
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Di Francesco V, Zamboni M, Zoico E, Mazzali G, Dioli A, Omizzolo F, Bissoli L, Fantin F, Rizzotti P, Solerte SB, Micciolo R, Bosello O. Unbalanced serum leptin and ghrelin dynamics prolong postprandial satiety and inhibit hunger in healthy elderly: another reason for the " anorexia of aging". Am J Clin Nutr 2006; 83:1149-52. [PMID: 16685059 DOI: 10.1093/ajcn/83.5.1149] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND In healthy elderly, a reduction from the appetite and food intake of younger years has been defined as the "anorexia of aging," which may cause malnutrition. Leptin and ghrelin may alter the control of hunger and satiety and thus lead to anorexia. OBJECTIVE The aim of this study was to investigate how aging affects serum leptin and ghrelin concentrations in response to a meal and the relation of those hormones to hunger and satiety sensations. DESIGN We studied 8 community-dwelling elderly (x +/- SD age: 78 +/- 1 y) subjects and 8 younger (29.5 +/- 1 y) control subjects. Under fasting conditions and for 4 h after an 800-kcal mixed meal, satiety and hunger were evaluated at intervals, by using a visual analogic scale. Blood samples for leptin, ghrelin, and insulin measurements were collected at the following times: 30 min before and immediately and 30, 60, 120, and 240 min after the meal. RESULTS Postprandial satiety lasted significantly longer in the elderly than in the control subjects, and hunger was suppressed in the elderly throughout the observation. Fasting leptin was higher in the elderly than in the young (x +/- SE: 4.3 +/- 1.9 and 1.3 +/- 0.4 ng/mL, respectively; P < 0.05), and postprandial fluctuation was not significant. Fasting insulin also was significantly higher in the elderly than in the young (6.8 +/- 1.3 and 3.5 +/- 0.6 mU/L, respectively; P < 0.05), and the postprandial insulin rise was greater in the elderly. Fasting and postprandial ghrelin values did not differ significantly between the 2 groups. Insulin was inversely correlated with hunger and directly correlated with satiety scores. CONCLUSIONS In healthy elderly, anorexigenic signals prevail over orexigenic signals, and they contribute to prolonged satiety and inhibition of hunger. This condition may lead to a calorie deficit and finally to malnutrition in the elderly.
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Comparative Study |
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Rezek M, Vanderweele DA, Novin D. Stages in the recovery of feeding following vagotomy in rabbits. BEHAVIORAL BIOLOGY 1975; 14:75-84. [PMID: 1137535 DOI: 10.1016/s0091-6773(75)90338-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Meyerholz DK, Grubor B, Fach SJ, Sacco RE, Lehmkuhl HD, Gallup JM, Ackermann MR. Reduced clearance of respiratory syncytial virus infection in a preterm lamb model. Microbes Infect 2004; 6:1312-9. [PMID: 15555538 PMCID: PMC2791065 DOI: 10.1016/j.micinf.2004.08.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2004] [Accepted: 08/20/2004] [Indexed: 11/23/2022]
Abstract
Respiratory syncytial virus (RSV) causes significant respiratory disease in children worldwide. For the study of severe RSV disease seen in preterm infants, a suitable animal model is lacking. The novel hypothesis of this study was that preterm lambs are susceptible to bovine RSV (bRSV) infection, an analogous pneumovirus with ruminant host specificity, and that there would be age-dependent differences in select RSV disease parameters. During RSV infection, preterm lambs had elevated temperatures and respiration rates with mild anorexia and cough compared to controls. Gross lesions included multifocal consolidation and atelectasis with foci of hyperinflation. Microscopic lesions included multifocal alveolar septal thickening and bronchiolitis. Immunohistochemistry localized the RSV antigen to all layers of bronchiolar epithelium from a few basal cells to numerous sloughing epithelia. A few mononuclear cells were also immunoreactive. To assess for age-dependent differences in RSV infection, neonatal lambs were infected similarly to the preterm lambs or with a high-titer viral inoculum. Using morphometry at day 7 of infection, preterm lambs had significantly more cellular immunoreactivity for RSV antigen (P <0.05) and syncytial cell formation (P <0.05) than either group of neonatal lambs. This work suggests that perinatal RSV clearance is age-dependent, which may explain the severity of RSV infection in preterm infants. The preterm lamb model is useful for assessing age-dependent mechanisms of severe RSV infection.
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Research Support, Non-U.S. Gov't |
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Review |
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Francois M, Canal Delgado I, Shargorodsky N, Leu CS, Zeltser L. Assessing the effects of stress on feeding behaviors in laboratory mice. eLife 2022; 11:e70271. [PMID: 35167441 PMCID: PMC8846584 DOI: 10.7554/elife.70271] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 12/21/2021] [Indexed: 12/17/2022] Open
Abstract
Stress often affects eating behaviors, increasing caloric intake in some individuals and decreasing it in others. The determinants of feeding responses to stress are unknown, in part because this issue is rarely studied in rodents. We focused our efforts on the novelty-suppressed feeding (NSF) assay, which uses latency to eat as readout of anxiety-like behavior, but rarely assesses feeding per se. We explored how key variables in experimental paradigms - estrous and diurnal cyclicity, age and duration of social isolation, prandial state, diet palatability, and elevated body weight - influence stress-induced anxiety-like behavior and food intake in male and female C57BL/6J mice. Latency to eat in the novel environment is increased in both sexes across most of the conditions tested, while effects on caloric intake are variable. In the common NSF assay (i.e., lean mice in the light cycle), sex-specific effects of the length of social isolation, and not estrous cyclicity, are the main source of variability. Under conditions that are more physiologically relevant for humans (i.e., overweight mice in the active phase), the novel stress now elicits robust hyperphagia in both sexes . This novel model of stress eating can be used to identify underlying neuroendocrine and neuronal substrates. Moreover, these studies can serve as a framework to integrate cross-disciplinary studies of anxiety and feeding related behaviors in rodents.
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Myers EA, Banihashemi L, Rinaman L. The anxiogenic drug yohimbine activates central viscerosensory circuits in rats. J Comp Neurol 2006; 492:426-41. [PMID: 16228990 DOI: 10.1002/cne.20727] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Systemic administration of the alpha(2)-adrenoceptor antagonist yohimbine (YO) activates the HPA stress axis and promotes anxiety in humans and experimental animals. We propose that visceral malaise contributes to the stressful and anxiogenic effects of systemic YO and that YO recruits brainstem noradrenergic (NA) and peptidergic neurons that relay viscerosensory signals to the hypothalamus and limbic forebrain. To begin testing these hypotheses, the present study explored dose-related effects of YO on food intake, conditioned flavor avoidance (CFA), and Fos immunolabeling in rats. Systemic YO (5.0 mg/kg BW, i.p.) inhibited food intake, supported CFA, and increased Fos immunolabeling in identified NA neurons in the ventrolateral medulla, nucleus of the solitary tract, and locus coeruleus. YO also increased Fos in the majority of corticotropin releasing hormone-positive neurons in the paraventricular nucleus of the hypothalamus. YO administered at 1.0 mg/kg BW did not inhibit food intake, did not support CFA, and did not increase Fos immunolabeling. Retrograde neural tracing demonstrated that neurons activated by YO at 5.0 mg/kg BW included medullary and pontine neurons that project to the central nucleus of the amygdala and to the lateral bed nucleus of the stria terminalis, the latter region receiving comparatively greater input by Fos-positive neurons. We conclude that YO produces anorexigenic and aversive effects that correlate with activation of brainstem viscerosensory inputs to the limbic forebrain. These findings invite continued investigation of how central viscerosensory signaling pathways interact with hypothalamic and limbic regions to influence interrelated physiological and behavioral components of anxiety, stress, and visceral malaise.
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Harrop EN, Hutcheson R, Harner V, Mensinger JL, Lindhorst T. "You Don't Look Anorexic": Atypical anorexia patient experiences of weight stigma in medical care. Body Image 2023; 46:48-61. [PMID: 37236121 PMCID: PMC10524894 DOI: 10.1016/j.bodyim.2023.04.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 04/23/2023] [Accepted: 04/25/2023] [Indexed: 05/28/2023]
Abstract
Eating disorders (ED) and weight stigma pose significant healthcare challenges. Patients at higher weights, like some with atypical anorexia (AAN), may face increased challenges due to weight stigma. This study analyzed patients' lived experiences with weight stigma in healthcare. Thirty-eight adult patients with AAN completed in-depth, semi-structured interviews regarding healthcare experiences. Guided by narrative inquiry approaches, transcripts were thematically coded. Across the illness trajectory (ED development, pre-treatment, treatment, post-treatment), patients reported that weight stigma in healthcare contributed to initiation and persistence of ED behaviors. Themes included "providers pathologizing patient weight," which patients reported triggered ED behaviors and relapse, "provider minimization and denial" of patients' EDs, which contributed to delays in screening and care, and "overt forms of weight discrimination," leading to healthcare avoidance. Participants reported that weight stigma prolonged ED behaviors, delayed care, created suboptimal treatment environments, deterred help-seeking, and lowered healthcare utilization. This suggests that many providers (pediatricians, primary care providers, ED treatment specialists, other healthcare specialists) may inadvertently reinforce patients' EDs. Increasing training, screening for EDs across the weight spectrum, and targeting health behavior promotion rather than universal weight loss, could enhance quality of care and improve healthcare engagement for patients with EDs, particularly those at higher weights.
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