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1.
Parasitol Res ; 120(5): 1845-1850, 2021 May.
Article in English | MEDLINE | ID: mdl-33666756

ABSTRACT

A reintroduced white-tailed sea eagle (Haliaeetus albicilla) in moderate body condition was found dead and submitted for post-mortem examination. There were no signs of disease on gross pathological examination. Histopathological examination however revealed the presence of encysted protozoan parasites in pectoral and cardiac muscle sections. Polymerase chain reaction amplification of extracted genomic DNA and sequencing of four regions: the 18S rDNA, 28S rDNA, internal transcribed spacer (ITS) 1, and RNA polymerase B (rpoB) loci, confirmed the presence of a Sarcocystis species in pectoral and cardiac muscle which appeared phylogenetically similar to Sarcocystis wobeseri. This is the first report of S. wobeseri-like infection in a white-tailed sea eagle revealing a new intermediate host species for this parasite.


Subject(s)
Bird Diseases/parasitology , Eagles/parasitology , Sarcocystis/isolation & purification , Sarcocystosis/veterinary , Animals , DNA, Ribosomal/genetics , Male , Phylogeny , Polymerase Chain Reaction , Sarcocystis/genetics , Sarcocystis/physiology , Sarcocystosis/parasitology
2.
Int J Obes (Lond) ; 42(2): 129-138, 2018 02.
Article in English | MEDLINE | ID: mdl-28925405

ABSTRACT

BACKGROUND/OBJECTIVES: The MATADOR (Minimising Adaptive Thermogenesis And Deactivating Obesity Rebound) study examined whether intermittent energy restriction (ER) improved weight loss efficiency compared with continuous ER and, if so, whether intermittent ER attenuated compensatory responses associated with ER. SUBJECTS/METHODS: Fifty-one men with obesity were randomised to 16 weeks of either: (1) continuous (CON), or (2) intermittent (INT) ER completed as 8 × 2-week blocks of ER alternating with 7 × 2-week blocks of energy balance (30 weeks total). Forty-seven participants completed a 4-week baseline phase and commenced the intervention (CON: N=23, 39.4±6.8 years, 111.1±9.1 kg, 34.3±3.0 kg m-2; INT: N=24, 39.8±9.5 years, 110.2±13.8 kg, 34.1±4.0 kg m-2). During ER, energy intake was equivalent to 67% of weight maintenance requirements in both groups. Body weight, fat mass (FM), fat-free mass (FFM) and resting energy expenditure (REE) were measured throughout the study. RESULTS: For the N=19 CON and N=17 INT who completed the intervention per protocol, weight loss was greater for INT (14.1±5.6 vs 9.1±2.9 kg; P<0.001). INT had greater FM loss (12.3±4.8 vs 8.0±4.2 kg; P<0.01), but FFM loss was similar (INT: 1.8±1.6 vs CON: 1.2±2.5 kg; P=0.4). Mean weight change during the 7 × 2-week INT energy balance blocks was minimal (0.0±0.3 kg). While reduction in absolute REE did not differ between groups (INT: -502±481 vs CON: -624±557 kJ d-1; P=0.5), after adjusting for changes in body composition, it was significantly lower in INT (INT: -360±502 vs CON: -749±498 kJ d-1; P<0.05). CONCLUSIONS: Greater weight and fat loss was achieved with intermittent ER. Interrupting ER with energy balance 'rest periods' may reduce compensatory metabolic responses and, in turn, improve weight loss efficiency.


Subject(s)
Caloric Restriction , Energy Intake/physiology , Energy Metabolism/physiology , Obesity/prevention & control , Thermogenesis/physiology , Weight Loss/physiology , Adult , Basal Metabolism/physiology , Body Composition , Female , Humans , Male , Middle Aged , Obesity/metabolism , Obesity/physiopathology , Rest/physiology , Treatment Outcome
3.
Int J Obes (Lond) ; 42(3): 561-571, 2018 03.
Article in English | MEDLINE | ID: mdl-29026214

ABSTRACT

OBJECTIVES: To test the potential efficacy of recombinant macrophage inhibitory cytokine-1 (MIC-1/GDF15) as an obesity therapeutic. METHODS: Male C57BL/6 J mice, either fed on normal chow or high-fat diet for 16 weeks to induce diet-induced obesity, were infused with either recombinant MIC-1/GDF15 or vehicle for 34 days by osmotic minipump. During the experimental period metabolic parameters were measured. Blood and tissue were collected for analysis of inflammatory markers. RESULTS: MIC-1/GDF15 decreased food intake and body weight of high-fat-fed and chow-fed mice compared with their vehicle-treated control mice. MIC-1/GDF15 reduced body weight, accompanied by greater reduction in fat mass in high-fat-fed mice compared to its effect on chow-fed mice. Further, whilst MIC-1/GDF15-treated chow-fed mice lost lean as well as fat mass, MIC-1/GDF15-treated high-fat-fed mice lost fat mass alone. This reduction in body weight and adiposity was due largely to reduced food intake, but MIC-1/GDF15-treated high-fat-fed mice also displayed increased energy expenditure that may be due to increased thermogenesis. MIC-1/GDF15-treated high-fat-fed mice also had higher circulating level of adiponectin and lower tissue expression, and circulating levels of leptin and inflammatory mediators associated with insulin resistance. Peripheral insulin and glucose intolerance were improved in both MIC-1/GDF15-treated high-fat-fed and chow-fed mice compared to that of their vehicle-treated control mice. CONCLUSIONS: MIC-1/GDF15 is highly effective in reducing adiposity and correcting the metabolic dysfunction of mice with high-fat fed. These studies suggest that MIC-1/GDF15 may be a candidate anti-obesity therapeutic.


Subject(s)
Adiposity/drug effects , Diet, High-Fat/adverse effects , Growth Differentiation Factor 15/pharmacology , Obesity/metabolism , Animals , Body Weight/drug effects , Eating/drug effects , Energy Metabolism/drug effects , Male , Mice , Mice, Inbred C57BL , Obesity/etiology , Obesity/physiopathology , Recombinant Proteins/pharmacology
4.
Int J Obes (Lond) ; 41(7): 1148-1153, 2017 07.
Article in English | MEDLINE | ID: mdl-28337025

ABSTRACT

BACKGROUND: Obesity and eating disorders are often studied and treated separately. While the increases in obesity prevalence are well known, examination of its co-occurrence with eating disorders, a problem also of public health concern, is important because eating disorder behaviors are known to contribute to obesity onset and maintenance, and vice versa. METHODS: Data from large cross-sectional representative statewide community samples of people in the years of 1995 (n=3001), 2005 (n=3047) and 2015 (n=3005) were analyzed. Data were collected using a structured, self-report interview that included demographic, health-related, weight, height and eating disorder behavior questions. Eating behavior questions assessed binge eating, very strict dieting/fasting and purging, and were derived from the Eating Disorder Examination. Logistic regression analyses were conducted comparing prevalence of obesity, eating disorder behaviors and their co-occurrence. RESULTS: The prevalence of obesity or binge eating, or obesity with comorbid binge eating, each increased significantly from 1995 to 2005 (P<0.001 for each comparison) and continued to increase significantly from 2005 to 2015 (P<0.001 for each comparison). The highest increases from 1995 to 2015 were in the prevalence of obesity with comorbid binge eating (7.3-fold), or obesity with comorbid very strict dieting/fasting (11.5-fold). The prevalence of very strict dieting/fasting also increased significantly from 1995 to 2015 (3.8-fold). The prevalence of purging, or obesity with comorbid purging, did not change significantly from 1995 to 2015. CONCLUSION: There were statewide increases during the 20 years from 1995 to 2015 in the independent prevalence of obesity, binge eating and very strict dieting/fasting, and even higher increases in the prevalence of obesity with comorbid binge eating, and obesity with comorbid very strict dieting/fasting. These findings support the need for more integrated approaches to both the prevention and treatment of obesity and eating disorder behaviors, namely binge eating and very strict dieting/fasting.


Subject(s)
Feeding and Eating Disorders/epidemiology , Obesity/epidemiology , Adolescent , Adult , Age Distribution , Comorbidity , Cross-Sectional Studies , Feeding and Eating Disorders/psychology , Female , Health Surveys , Humans , Male , Middle Aged , Obesity/psychology , Population Surveillance , Prevalence , Risk Factors , South Australia/epidemiology , Young Adult
5.
Int J Obes (Lond) ; 37(3): 390-8, 2013 Mar.
Article in English | MEDLINE | ID: mdl-22565420

ABSTRACT

BACKGROUND: Estrogen deficiency increases body weight or total and central adiposity and decreases energy expenditure. Hypothalamic neuropeptide Y (NPY) expression is altered by estrogen deficiency in rodents, but the long-term consequences on energy homeostasis are unknown. OBJECTIVE: To investigate the role of NPY in the changes in energy expenditure and physical activity, as well as the associated changes in body weight and composition in response to short-term and long-term estrogen deficiency. DESIGN: Sham and ovariectomy (OVX) operations were performed at 8 weeks of age in wild-type (WT) and NPY(-/-) mice. Energy expenditure, physical activity, body composition and weight, as well as food intake were measured at 10-18 days (short-term) and 46-54 days (long-term) after OVX. RESULTS: OVX influences energy homeostasis differently at early compared with later time-points. At the early but not the late time point, OVX in WT mice reduced oxygen consumption and energy expenditure and tended to reduce resting metabolic rate. Interestingly, these effects of short-term estrogen deficiency were ablated by NPY deletion, with NPY(-/-) mice exhibiting significant increases in energy expenditure and resting metabolic rate. In addition to these hypermetabolic effects, OVX NPY(-/-) mice exhibited significantly lower body weight and whole-body fat mass relative to OVX WT controls at the short-term but not the long-term time point. Food intake and physical activity were unaltered by OVX, but NPY(-/-) mice exhibited significant reductions in these parameters relative to WT. CONCLUSION: The effects of estrogen deficiency to reduce energy metabolism are transient, and NPY is critical to this effect as well as the early OVX-induced obesity.


Subject(s)
Estrogens/deficiency , Hypothalamus/metabolism , Neuropeptide Y/metabolism , Adipose Tissue/metabolism , Analysis of Variance , Animals , Blotting, Western , Body Weight , Calorimetry , Eating , Energy Metabolism , Estrogens/metabolism , Female , Homeostasis , Mice , Ovariectomy , Physical Conditioning, Animal
6.
Diabetes Obes Metab ; 14(8): 727-36, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22369253

ABSTRACT

AIMS: Both the neuronal-derived neuropeptide Y (NPY) and the gut hormone peptide YY (PYY) have been implicated in the regulation of energy balance and glucose homeostasis. However, despite similar affinities for the same Y receptors, the co-ordinated actions of these two peptides in energy and glucose homeostasis remain largely unknown. METHODS: To investigate the mechanisms and possible interactions between PYY with NPY in the regulation of these processes, we utilized NPY/PYY single and double mutant mouse models and examined parameters of energy balance and glucose homeostasis. RESULTS: PYY(-/-) mice exhibited increased fasting-induced food intake, enhanced fasting and oral glucose-induced serum insulin levels, and an impaired insulin tolerance, - changes not observed in NPY(-/-) mice. Interestingly, whereas PYY deficiency-induced impairment in insulin tolerance remained in NPY(-/-) PYY(-/-) mice, effects of PYY deficiency on fasting-induced food intake and serum insulin concentrations at baseline and after the oral glucose bolus were absent in NPY(-/-) PYY(-/-) mice, suggesting that NPY signalling may be required for PYY's action on insulin secretion and fasting-induced hyperphagia. Moreover, NPY(-/-) PYY(-/-) , but not NPY(-/-) or PYY(-/-) mice had significantly decreased daily food intake, indicating interactive control by NPY and PYY on spontaneous food intake. Furthermore, both NPY(-/-) and PYY(-/-) mice showed significantly reduced respiratory exchange ratio during the light phase, with no additive effects observed in NPY(-/-) PYY(-/-) mice, indicating that NPY and PYY may regulate oxidative fuel selection via partly shared mechanisms. Overall, physical activity and energy expenditure, however, are not significantly altered by NPY and PYY single or double deficiencies. CONCLUSIONS: These findings show significant and diverse interactions between NPY and PYY signalling in the regulation of different aspects of energy balance and glucose homeostasis.


Subject(s)
Adipose Tissue/metabolism , Neuropeptide Y/metabolism , Peptide YY/metabolism , Animals , Eating , Energy Metabolism , Fasting/blood , Glucose Tolerance Test , Homeostasis , Mice , Mice, Inbred C57BL , Mice, Knockout , Motor Activity , Neuropeptide Y/genetics , Neuropeptide Y/pharmacology , Peptide YY/genetics , Signal Transduction
7.
Diabetologia ; 54(4): 910-21, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21181398

ABSTRACT

AIMS/HYPOTHESIS: Diabetes in pregnancy is linked to development of obesity in the offspring, but the mechanisms are not fully understood. Gestational diabetes mellitus (GDM) occurs when beta cells are unable to compensate for the normal insulin resistance of late pregnancy. In this study, we used a murine model of beta cell dysfunction to examine the effects of maternal GDM on phenotype in male offspring with and without an inherited predisposition for beta cell dysfunction. METHODS: Beta cell-specific aryl-hydrocarbon receptor nuclear translocator-null (ßArnt) mice develop GDM from beta cell dysfunction. ßArnt and control female mice were used to induce GDM and non-diabetic pregnancies, respectively. RESULTS: Offspring from GDM pregnancies became spontaneously obese on a normal-chow diet. They were heavier than offspring from non-diabetic pregnancies, with increased body fat. Respiratory exchange ratio (RER) was higher, indicating decreased capacity to switch to lipid oxidation. Metabolic rate in GDM offspring was decreased prior to onset of obesity. The phenotype was more pronounced in ßArnt GDM offspring than in GDM offspring of control genotype, demonstrating an interaction between genotype and pregnancy exposure. ßArnt GDM offspring had increased hypothalamic neuropeptide Y (Npy) and decreased pro-opiomelanocortin (Pomc) expression. Weight, body fat, insulin sensitivity and RER in all mice, and hypothalamic Npy in ßArnt mice were significantly correlated with AUC of maternal late pregnancy glucose tolerance tests (p < 0.01), but not with litter size, maternal weight, triacylglycerol or pre-pregnancy glycaemia. CONCLUSIONS/INTERPRETATION: In ßArnt mice, exposure to GDM and inheritance of genetic beta cell dysfunction had additive effects on male offspring obesity; severity of the offspring phenotype correlated with maternal glycaemia.


Subject(s)
Diabetes, Gestational/physiopathology , Glucose Intolerance/physiopathology , Insulin-Secreting Cells/pathology , Adiposity/genetics , Adiposity/physiology , Animals , Aryl Hydrocarbon Receptor Nuclear Translocator/genetics , Aryl Hydrocarbon Receptor Nuclear Translocator/metabolism , Birth Weight/genetics , Birth Weight/physiology , Diabetes, Gestational/genetics , Eating/genetics , Eating/physiology , Female , Glucose Intolerance/genetics , Insulin-Secreting Cells/metabolism , Male , Mice , Mice, Knockout , Neuropeptides/metabolism , Obesity/genetics , Pregnancy , Pregnancy Complications
8.
Int J Obes (Lond) ; 34(2): 357-73, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19918245

ABSTRACT

OBJECTIVE: Neuropeptide Y and its Y receptors are important players in the regulation of energy homeostasis. However, while their functions in feeding regulation are well recognized, functions in other critical aspects of energy homeostasis are largely unknown. To investigate the function of Y1 receptors in the regulation of energy homeostasis, we examined energy expenditure, physical activity, body composition, oxidative fuel selection and mitochondrial oxidative capacity in germline Y1(-/-) mice as well as in a conditional Y1-receptor-knockdown model in which Y1 receptors were knocked down in peripheral tissues of adult mice. RESULTS: Germline Y1(-/-) mice of both genders not only exhibit a decreased respiratory exchange ratio, indicative of increased lipid oxidation, but interestingly also develop late-onset obesity. However, the increased lipid oxidation is a primary effect of Y1 deletion rather than secondary to increased adiposity, as young Y1(-/-) mice are lean and show the same effect. The mechanism behind this is likely because of increased liver and muscle protein levels of carnitine palmitoyltransferase-1 (CPT-1) and maximal activity of key enzymes involved in beta-oxidation; beta-hydroxyacyl CoA dehydrogenase (betaHAD) and medium-chain acyl-CoA dehydrogenase (MCAD), leading to increased mitochondrial capacity for fatty acid transport and oxidation. These effects are controlled by peripheral Y1-receptor signalling, as adult-onset conditional Y1 knockdown in peripheral tissues also leads to increased lipid oxidation, liver CPT-1 levels and betaHAD activity. Importantly, these mice are resistant to diet-induced obesity. CONCLUSIONS: This work shows the primary function of peripheral Y1 receptors in the regulation of oxidative fuel selection and adiposity, opening up new avenues for anti-obesity treatments by targeting energy utilization in peripheral tissues rather than suppressing appetite by central effects.


Subject(s)
Energy Metabolism/physiology , Fatty Acids/metabolism , Neuropeptide Y/metabolism , Obesity/metabolism , Receptors, Neuropeptide Y/physiology , 3-Hydroxyacyl CoA Dehydrogenases/metabolism , Acyl-CoA Dehydrogenase/metabolism , Animals , Body Composition , Carnitine O-Palmitoyltransferase/metabolism , Female , Homeostasis/physiology , Male , Mice , Mitochondria/metabolism , Motor Activity , Obesity/physiopathology , Oxidation-Reduction
9.
Diabetes Obes Metab ; 12(7): 591-603, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20590734

ABSTRACT

AIMS: Energy homeostasis is regulated by a complex interaction of molecules and pathways, and new antiobesity treatments are likely to require multiple pharmacological targeting of anorexigenic or orexigenic pathways to achieve effective loss of excess body weight and adiposity. Cannabinoids, acting via the cannabinoid-1 (CB1) receptor, and neuropeptide Y (NPY) are important modulators of feeding behaviour, energy metabolism and body composition. We investigated the interaction of CB1 and NPY in the regulation of energy homeostasis, hypothesizing that dual blockade of CB1 and NPY signalling will induce greater weight and/or fat loss than that induced by single blockade of either system alone. METHODS: We studied the effects of the CB1 antagonist Rimonabant on food intake, body weight, body composition, energy metabolism and bone physiology in wild-type (WT) and NPY knockout (NPY(-/-)) mice. Rimonabant was administered orally at 10 mg/kg body weight twice per day for 3 weeks. Oral Rimonabant was delivered voluntarily to mice via a novel method enabling studies to be carried out in the absence of gavage-induced stress. RESULTS: Mice with dual blockade of CB1 and NPY signalling (Rimonabant-treated NPY(-/-) mice) exhibited greater reductions in body weight and adiposity than mice with single blockade of either system alone (Rimonabant-treated WT or vehicle-treated NPY(-/-) mice). These changes occurred without loss of lean tissue mass or bone mass. Furthermore, Rimonabant-treated NPY(-/-) mice showed a lower respiratory exchange ratio than that seen in Rimonabant-treated WT or vehicle-treated NPY(-/-) mice, suggesting that this additive effect of dual blockade of CB1 and NPY involves promotion of lipid oxidation. On the other hand, energy expenditure and physical activity were comparable amongst all treatment groups. Interestingly, Rimonabant similarly and transiently reduced spontaneous and fasting-induced food intake in WT and NPY(-/-) mice in the first hour after administration only, suggesting independent regulation of feeding by CB1 and NPY signalling. In contrast, Rimonabant increased serum corticosterone levels in WT mice, but this effect was not seen in NPY(-/-) mice, indicating that NPY signalling may be required for effects of CB1 on the hypothalamo-pituitary-adrenal axis. CONCLUSIONS: Dual blockade of CB1 and NPY signalling leads to additive reductions in body weight and adiposity without concomitant loss of lean body mass or bone mass. An additive increase in lipid oxidation in dual CB1 and NPY blockade may contribute to the effect on adiposity. These findings open new avenues for more effective treatment of obesity via dual pharmacological manipulations of the CB1 and NPY systems.


Subject(s)
Eating/drug effects , Neuropeptide Y/drug effects , Obesity/drug therapy , Piperidines/antagonists & inhibitors , Pyrazoles/antagonists & inhibitors , Receptor, Cannabinoid, CB1/antagonists & inhibitors , Receptors, Neuropeptide Y/drug effects , Animals , Body Composition , Energy Metabolism/drug effects , Homeostasis/physiology , Mice , Neuropeptide Y/metabolism , Obesity/metabolism , Oxidation-Reduction , Piperidines/administration & dosage , Pyrazoles/administration & dosage , Receptor, Cannabinoid, CB1/administration & dosage , Rimonabant
10.
Epidemiol Infect ; 138(7): 941-50, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20412610

ABSTRACT

The dramatic decline of the native red squirrel in the UK has been attributed to both direct and disease-mediated competition with the grey squirrel where the competitor acts as a reservoir host of squirrelpox virus (SQPV). SQPV is threatening red squirrel conservation efforts, yet little is known about its epidemiology. We analysed seroprevalence of antibody against SQPV in grey squirrels from northern England and the Scottish Borders in relation to season, weather, sex, and body weight using Generalized Linear Models in conjunction with Structural Equation Modelling. Results indicated a heterogeneous prevalence pattern which is male-biased, increases with weight and varies seasonally. Seroprevalence rose during the autumn and peaked in spring. Weather parameters had an indirect effect on SQPV antibody status. Our findings point towards a direct disease transmission route, which includes environmental contamination. Red squirrel conservation management options should therefore seek to minimize squirrel contact points.


Subject(s)
Parapoxvirus , Poxviridae Infections/veterinary , Rodent Diseases/epidemiology , Sciuridae/virology , Animals , Body Weight , England/epidemiology , Female , Male , Population Surveillance , Poxviridae Infections/epidemiology , Scotland/epidemiology , Seasons , Sex Factors , Weather
11.
Vet Rec ; 162(22): 716-21, 2008 May 31.
Article in English | MEDLINE | ID: mdl-18515759

ABSTRACT

Iron storage disease (haemochromatosis) is thought to be the cause of many disorders unique to captive black rhinoceroses (Diceros bicornis). To establish reliable reference ranges for iron parameters, serum samples from 27 eastern black rhinoceroses (Diceros bicornis michaeli) from a translocation programme in Kenya were analysed and compared with the samples from 17 captive individuals. The transferrin saturation, serum iron concentration and gamma glutamyl transferase were significantly higher in the captive rhinoceroses, but these elevations were not evident when the results were compared with previously published data.


Subject(s)
Animals, Wild/blood , Animals, Zoo/blood , Iron/blood , Perissodactyla/blood , Transferrin/analysis , gamma-Glutamyltransferase/blood , Animals , Female , Hemochromatosis/blood , Hemochromatosis/veterinary , Kenya , Male , Reference Values
12.
Obes Rev ; 19(10): 1412-1423, 2018 10.
Article in English | MEDLINE | ID: mdl-30144269

ABSTRACT

Although very low energy diets (VLEDs) are the most successful non-surgical, non-pharmacological treatment for obesity, they are underutilized, and little is known about experiences of people using VLEDs for weight loss. This systematic review synthesizes qualitative studies investigating participants' experiences of undertaking a VLED composed of total meal replacement products to lose weight. Of the 4,911 articles screened, three studies met criteria for inclusion. Thematic synthesis was used to analyse the study findings. Health and appearance were the main motivators to use a VLED for weight loss. Adherence was facilitated by group support meetings, rapid weight loss and ease of use of the diet. Being part of a clinical trial gave a sense of accountability and further reason to adhere to a VLED, and the VLED itself was well accepted by users. Barriers to adherence, such as temptations and social occasions, were overcome by avoidance and distraction strategies. In conclusion, this qualitative synthesis of users' experiences of VLEDs shows that VLEDs are well accepted and positively viewed by users. More in-depth research could facilitate understanding of how this weight loss strategy influences the weight maintenance period, in order to facilitate better long-term results.


Subject(s)
Caloric Restriction , Diet, Reducing , Obesity/diet therapy , Overweight/diet therapy , Humans , Treatment Outcome , Weight Loss
13.
Obes Rev ; 19 Suppl 1: 47-60, 2018 12.
Article in English | MEDLINE | ID: mdl-30511512

ABSTRACT

Eating patterns involving intermittent energy restriction (IER) include 'intermittent fasting' where energy intake is severely restricted for several 'fasting' days per week, with 'refeeding' days (involving greater energy intake than during fasting days) at other times. Intermittent fasting does not improve weight loss compared to continuous energy restriction (CER), where energy intake is restricted every day. We hypothesize that weight loss from IER could be improved if refeeding phases involved restoration of energy balance (i.e. not ongoing energy restriction, as during intermittent fasting). There is some evidence in adults with overweight or obesity showing that maintenance of a lower weight may attenuate (completely or partially) some of the adaptive responses to energy restriction that oppose ongoing weight loss. Other studies show some adaptive responses persist unabated for years after weight loss. Only five randomized controlled trials in adults with overweight or obesity have compared CER with IER interventions that achieved energy balance (or absence of energy restriction) during refeeding phases. Two reported greater weight loss than CER, whereas three reported similar weight loss between interventions. While inconclusive, it is possible that achieving energy balance (i.e. avoiding energy restriction or energy excess) during refeeding phases may be important in realizing the potential of IER.


Subject(s)
Adaptation, Physiological/physiology , Caloric Restriction , Fasting/physiology , Feeding Behavior/physiology , Obesity/diet therapy , Body Mass Index , Diet, Reducing , Energy Intake/physiology , Energy Metabolism/physiology , Humans
14.
J Clin Invest ; 92(1): 155-9, 1993 Jul.
Article in English | MEDLINE | ID: mdl-8325980

ABSTRACT

Aldose reductase (AR) is implicated in the pathogenesis of the diabetic complications and osmotic cataract. AR has been identified as an osmoregulatory protein, at least in the renal medulla. An outstanding question relates to the response of AR gene expression to diet-induced galactosemia in extrarenal tissues. This paper shows that AR gene expression in different tissues is regulated by a complex multifactorial mechanism. Galactose feeding in the rat is associated with a complex and, on occasions, multiphasic pattern of changes in AR mRNA levels in kidney, testis, skeletal muscle, and brain. These changes are not in synchrony with the temporal sequence of changes in tissue galactitol, galactose, and myoinositol concentrations. Moreover, galactose feeding results in changes in tissue AR activities that are not related, temporally or quantitatively, to the alterations in tissue AR mRNA or galactitol levels. It is concluded that AR gene expression and tissue AR activities are regulated by mechanisms that are not purely dependent on nonspecific alterations in intracellular metabolite concentrations. This conclusion is supported by the finding that chronic xylose feeding, despite being associated with intracellular xylitol accumulation, does not result in alterations in AR mRNA levels, at least in the kidney.


Subject(s)
Aldehyde Reductase/genetics , Galactose/metabolism , Animals , Brain/metabolism , Galactitol/metabolism , Gene Expression , Inositol/metabolism , Kidney/metabolism , Male , Muscles/metabolism , RNA, Messenger/genetics , Rats , Rats, Wistar , Testis/metabolism , Xylitol/metabolism , Xylose/metabolism
15.
J Clin Invest ; 105(9): 1253-9, 2000 May.
Article in English | MEDLINE | ID: mdl-10792000

ABSTRACT

Chronic central administration of neuropeptide Y (NPY) causes hyperphagia, hyperinsulinemia, and obesity, a response that is prevented by prior adrenalectomy (ADX) in rats. The basis of NPY's effect and how the acute responses to this peptide are affected by ADX remain unknown. This study investigates the role of glucocorticoids in acute NPY-stimulated food intake, acute NPY-induced insulin release, and hypothalamic NPY-receptor mRNA expression levels. NPY-induced food intake was similar in ADX and control rats after acute intracerebroventricular injection of NPY. Injection of NPY caused a significant increase in plasma insulin in control rats, but this effect was completely absent in ADX rats in which basal plasma insulin levels were also lower than controls. In addition, ADX significantly reduced the number of neurons expressing NPY receptor Y(1) and Y(5) mRNAs in the ventromedial hypothalamus (VMH), without affecting Y(1)- or Y(5)-mRNA expression in the paraventricular hypothalamus or the arcuate nucleus. These data indicate that glucocorticoids are necessary for acute NPY-mediated insulin release and suggest that the mechanisms involve glucocorticoid regulation of Y(1) and Y(5) receptors specifically within the VMH nucleus.


Subject(s)
Adrenal Glands/physiology , Insulin/metabolism , Neuropeptide Y/pharmacology , Receptors, Neuropeptide Y/biosynthesis , Ventromedial Hypothalamic Nucleus/physiology , Adrenalectomy , Animals , Eating/drug effects , In Situ Hybridization , Injections, Intraventricular , Insulin Secretion , Male , RNA, Messenger/biosynthesis , Rats , Rats, Wistar , Receptors, Neuropeptide Y/genetics
16.
Sci Total Environ ; 376(1-3): 116-27, 2007 Apr 15.
Article in English | MEDLINE | ID: mdl-17307237

ABSTRACT

Since 1989, a red kite Milvus milvus reintroduction programme has been underway in the United Kingdom, with 4-6 week old nestlings brought into captivity and held for 6-8 weeks before reintroduction. As scavengers, red kites may consume unretrieved game, and ingest shot or lead (Pb) fragments in their prey's flesh. We evaluated exposure to Pb in captive and wild red kites by taking blood samples from 125 captive young red kites prior to release, through analysing 264 pellets (regurgitated by wild birds) collected from under a roost site, and analysing Pb concentrations in livers and/or bones of 87 red kites found dead between 1995 and 2003. Lead isotope analyses of livers were also conducted in an effort to identify Pb exposure routes. Forty-six (36.8%) kites sampled prior to release had elevated blood Pb concentrations (201-3340 microg l(-1)). The source of this Pb was probably small fragments of lead ammunition in the carcasses of birds or mammals either fed to the nestlings by their parents or, more likely, subsequently whilst in captivity. Once released, kites were also exposed to lead shot in their food, and a minimum of 1.5-2.3% of regurgitated pellets contained Pb gunshot. Seven of 44 red kites found dead or that were captured sick and died within a few days had elevated (>6 mg kg(-1) dry weight [d.w.]) liver Pb concentrations, and six of these (14%) had concentrations of >15 mg kg(-1) d.w., compatible with fatal Pb poisoning. Post-mortem analyses indicated that two of these birds had died of other causes (poisoning by rodenticide and a banned agricultural pesticide); the remaining four (9%) probably died of Pb poisoning. Bone samples from 86 red kites showed a skewed distribution of Pb concentration, and 18 samples (21%) had Pb concentrations >20 mg kg(-1) d.w., indicating elevated exposure to Pb at some stage in the birds' life. Lead isotopic signatures (Pb (208/206); Pb (206/207)) in liver samples of the majority of kites were compatible with those found in lead shot extracted from regurgitated pellets. Lead isotope ratios found in the livers of kites with very low Pb concentrations were distinct from UK petrol Pb isotopic signatures, indicating that birds were exposed to little residual petrol Pb. We conclude that the primary source of Pb to which red kites are exposed is lead ammunition (shotgun pellets or rifle bullets), or fragments thereof, in their food sources; in some cases exposure appears sufficient to be fatal. We make recommendations to reduce Pb poisoning in both captive and wild red kites and other scavenging species.


Subject(s)
Environmental Pollutants/analysis , Falconiformes/metabolism , Lead/analysis , Animals , Bone and Bones/metabolism , Diet , Environmental Pollutants/metabolism , Falconiformes/blood , Firearms , Lead/metabolism , Liver/metabolism , Rabbits
17.
Ecohealth ; 14(Suppl 1): 84-91, 2017 03.
Article in English | MEDLINE | ID: mdl-27491684

ABSTRACT

Exposure to parasites in conservation translocations increases the risks to recipient and translocated populations from disease, and therefore there has been interest in implementing biosecurity methods. Using four case examples we described how biosecurity was applied in practical translocation scenarios prior to and during a translocation and also post-release. We implemented biosecurity, including quarantine barriers, at specific points in the translocation pathway where hazards, identified by the disease risk analysis, had the potential to induce disease. Evidence that biosecurity protected translocated and recipient populations, included an absence of mortality associated with high-risk non-native parasites, a reduction in mortality associated with endemic parasites, the absence of high-risk pathogenic parasites, or associated diseases, at the destination; and the apparent absence of diseases in closely related species at the destination site. The biosecurity protocols did not alter the level or duration of translocated species confinement and therefore probably did not act as a stressor. There is a monetary cost involved in biosecurity but the epidemiological evidence suggests that conservation translocation managers should carefully consider its use. Breakdowns in quarantine have occurred in human hospitals despite considerable investment and training for health professionals, and we therefore judge that there is a need for training in the objectives and maintenance of quarantine barriers in conservation translocations. Biosecurity protocols for conservation translocations should be continually updated in response to findings from disease risk analysis and post-release disease surveillance and we recommend further studies to evaluate their effectiveness.


Subject(s)
Anura , Bees , Conservation of Natural Resources , Moths , Passeriformes , Animals , Humans , Ranidae , Risk Assessment
18.
Transbound Emerg Dis ; 64(5): 1530-1548, 2017 Oct.
Article in English | MEDLINE | ID: mdl-27393743

ABSTRACT

There are risks from disease in undertaking wild animal reintroduction programmes. Methods of disease risk analysis have been advocated to assess and mitigate these risks, and post-release health and disease surveillance can be used to assess the effectiveness of the disease risk analysis, but results for a reintroduction programme have not to date been recorded. We carried out a disease risk analysis for the reintroduction of pool frogs (Pelophylax lessonae) to England, using information gained from the literature and from diagnostic testing of Swedish pool frogs and native amphibians. Ranavirus and Batrachochytrium dendrobatidis were considered high-risk disease threats for pool frogs at the destination site. Quarantine was used to manage risks from disease due to these two agents at the reintroduction site: the quarantine barrier surrounded the reintroduced pool frogs. Post-release health surveillance was carried out through regular health examinations of amphibians in the field at the reintroduction site and collection and examination of dead amphibians. No significant health or disease problems were detected, but the detection rate of dead amphibians was very low. Methods to detect a higher proportion of dead reintroduced animals and closely related species are required to better assess the effects of reintroduction on health and disease.


Subject(s)
Chytridiomycota , Mycoses/veterinary , Ranidae/microbiology , Animals , Animals, Wild , England , Mycoses/epidemiology , Mycoses/microbiology
19.
Neuropeptides ; 61: 87-93, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27823858

ABSTRACT

Germline deletion of the Prader-Willi syndrome (PWS) candidate gene Snord116 in mice leads to some classical symptoms of human PWS, notably reductions in body weight, linear growth and bone mass. However, Snord116 deficient mice (Snord116-/-) do not develop an obese phenotype despite their increased food intake and the underlying mechanism for that is unknown. We tested the phenotypes of germline Snord116-/- as well as neuropeptide Y (NPY) neuron specific Snord116lox/lox/NPYcre/+ mice at 30°C, the thermoneutral temperature of mice, and compared these to previous reports studies conducted at normal room temperature. Snord116-/- mice at 30°C still weighed less than wild type but had increased body weight gain. Importantly, food intake and energy expenditure were no longer different at 30°C, and the reduced bone mass and nasal-anal length observed in Snord116-/- mice at room temperature were also normalized. Mechanistically, the thermoneutral condition led to the correction of the mRNA expression of NPY and pro-opiomelanocortin (POMC), which were both previously observed to be significantly up-regulated at room temperature. Importantly, almost identical phenotypes and NPY/POMC mRNA expression alterations were also observed in Snord116lox/lox/NPYcre/+ mice, which lack the Snord116 gene only in NPY neurons. These data illustrate that mild cold stress is a critical factor preventing the development of obesity in Snord116-/- mice via the NPY system. Our study highlights that the function of Snord116 in the hypothalamus may be to enhance energy expenditure, likely via the NPY system, and also indicates that Snord116 function in mice is strongly dependent on environmental conditions such as cold exposure.


Subject(s)
Energy Metabolism/genetics , Homeostasis/genetics , Neurons/metabolism , Prader-Willi Syndrome/genetics , RNA, Small Nucleolar/genetics , Animals , Body Weight/genetics , Eating/genetics , Hypothalamus/metabolism , Mice , Mice, Knockout , Neuropeptide Y/genetics , Neuropeptide Y/metabolism , Prader-Willi Syndrome/metabolism , Pro-Opiomelanocortin/genetics , Pro-Opiomelanocortin/metabolism , RNA, Small Nucleolar/metabolism , Temperature
20.
Clin Obes ; 7(6): 354-359, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28801940

ABSTRACT

The prevalence of depression in those with obesity is reported to be as high as double that in individuals of normal weight. There is potentially a bi-directional relationship between obesity and depression. Some research has suggested that depression results in weight gain and obesity, and other studies have suggested that those with obesity are more likely to develop depression at a later stage. The aim of this study was to investigate the association of depression symptoms with weight change over a 12-month study. Seventy participants undertook a 3-month lifestyle (diet and exercise) weight loss intervention, and were followed up as part of a 12-month study. Participants completed the Beck Depression Inventory-II (BDI-II) and had their body weight measured throughout the study. Baseline body mass index (BMI) of participants (mean ± standard deviation [SD]) was 31.1 ± 3.9 kg m-2 , body weight was 89.4 ± 16.1 kg, and age was 45.4 ± 11.1 years; 63% of the cohort were female. The mean weight change from baseline to 3 months was -5.2% (±SD 4.3%), and from baseline to 12 months was -4.2% (±SD 6.1%). There was a significant decrease in BDI-II scores over the 12-month study, and a 1-unit decrease in BDI-II score was associated with a further decrease in body weight of -0.4%. The current study indicated that weight loss was associated with improvements in mood for non-clinically depressed individuals with obesity, and these improvements persisted during a period of 3-12 months of follow-up.


Subject(s)
Depression/etiology , Obesity/complications , Adolescent , Adult , Aged , Body Mass Index , Depression/psychology , Female , Humans , Life Style , Male , Middle Aged , Obesity/physiopathology , Obesity/psychology , Obesity Management , Prospective Studies , Psychiatric Status Rating Scales , Young Adult
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