Energy homeostasis : crosstalk between adipose tissue and the human hypothalamus

There is a worldwide epidemic of obesity. Weight rise is a consequence of continuous positive energy balance which leads to accumulation of body fat. Recent insights into adipose tissue (AT) biology have led to the conclusion that the adipocyte is not just a storage depot for triglycerides but also an endocrine organ. AT secretes proteins, such as leptin, which control central appetite regulation in the human hypothalamus. In contrast, several other proteins and neurotransmitters regulate central energy balance, but can also influence AT metabolism to elicit feedback on fat accumulation. This suggests a close link between AT and the brain within an AT-to-brain crosstalk system including feedback circuits. This thesis examines firstly, the potential of crosstalk between AT and the brain by other adipokines and secondly, the brain-AT crosstalk by expression of neurotransmitters and their receptors in AT. The study establishes the presence of the adipokines adiponectin and resistin in human cerebrospinal fluid and immunohistochemistry showed adiponectin receptors in energy regulating nuclei of the hypothalamus. Furthermore, this thesis established that the orexigenic neurotransmitters NPY and ghrelin are secreted by human adipocytes, where they enhance lipid accumulation. Further, that NPY levels increase with obesity and its in vitro secretion is enhanced by insulin. This may play an important role in the pathogenesis of the metabolic syndrome and may induce an escape of the appetite behaviour towards positive energy balance. Finally, this thesis highlights the influence of a depot-specific innervation of AT on energy homeostasis by establishing presence of nicotinic receptors in human adipocytes, which may play a role in smoking induced changes in adipokine secretion and fat mass. In conclusion, this thesis suggests a tight interplay between AT and the brain and highlights its potential relevance in human pathophysiology.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A role for SPARC in the moderation of human insulin secretion.

Published onlineJournal ArticleResearch Support, Non-U.S. Gov'tAIMS/HYPOTHESIS: We have previously shown the implication of the multifunctional protein SPARC (Secreted protein acidic and rich in cysteine)/osteonectin in insulin resistance but potential effects on beta-cell function have not been assessed. We therefore aimed to characterise the effect of SPARC on beta-cell function and features of diabetes. METHODS: We measured SPARC expression by qRT-PCR in human primary pancreatic islets, adipose tissue, liver and muscle. We then examined the relation of SPARC with glucose stimulated insulin secretion (GSIS) in primary human islets and the effect of SPARC overexpression on GSIS in beta cell lines. RESULTS: SPARC was expressed at measurable levels in human islets, adipose tissue, liver and skeletal muscle, and demonstrated reduced expression in primary islets from subjects with diabetes compared with controls (p< = 0.05). SPARC levels were positively correlated with GSIS in islets from control donors (p< = 0.01). Overexpression of SPARC in cultured beta-cells resulted in a 2.4-fold increase in insulin secretion in high glucose conditions (p< = 0.01). CONCLUSIONS: Our data suggest that levels of SPARC are reduced in islets from donors with diabetes and that it has a role in insulin secretion, an effect which appears independent of SPARC's modulation of obesity-induced insulin resistance in adipose tissue.Diabetes Research Wellness Foundatio

Review of interactions between host plants, aphids,primary parasitoids and hyperparasitoids in vegetable and cereal ecosystems in Slovenia

Sampling of aphids and parasitoids was conducted in diverse cereal and vegetable crop habitats in Slovenia in the period from 2006 to 2010. Over 330 samples containing primary or secondary parasitoids or both were taken. In 25 different vegetable crops 15 species of aphids parasitized by 18 species of primary parasitoids were found, and were associated with 13 species of secondary or hyperparasitoids. Eight species of primary parasitoids emerged from mummies of three species of cereal aphids. Aphidius ervl Haliday, A. rhopalosiphi de Stefani-Perez, A. uzbekistanicus Luzhetskl, and Ephedrus plagiator (Nees), are generally present in cereal crops and most abundant primary parasitoids in cereal crops in Slovenia. Nine species of hyperparasitoids were found both in cereal and vegetable crops, while four species, i.e. Alloxysta fulviceps Curtis, Coruna clavata Walker, Dendrocerus laticeps Hedicke and Pachyneuron formosum Walker, were found only in vegetable crops and two, Alloxysta brachyptera Hartig and Phaenoglyphis villosa Hartig, only in cereal. 30% of all hyperparasitoid species belonged to genus Alloxysta. Cereal and vegetable crops reveal a relatively diverse aphid parasitoid fauna that corresponds to diverse habitat, landscape and vegetation complexity in Slovenia

Parathyroid hormone, cognitive function and dementia: a systematic review

BACKGROUND: Metabolic factors are increasingly recognized to play an important role in the pathogenesis of Alzheimer's disease and dementia. Abnormal parathyroid hormone (PTH) levels play a role in neuronal calcium dysregulation, hypoperfusion and disrupted neuronal signaling. Some studies support a significant link between PTH levels and dementia whereas others do not. METHODS: We conducted a systematic review through January 2014 to evaluate the association between PTH and parathyroid conditions, cognitive function and dementia. Eleven electronic databases and citation indexes were searched including Medline, Embase and the Cochrane Library. Hand searches of selected journals, reference lists of primary studies and reviews were also conducted along with websites of key organizations. Two reviewers independently screened titles and abstracts of identified studies. Data extraction and study quality were performed by one and checked by a second reviewer using predefined criteria. A narrative synthesis was performed due to the heterogeneity of included studies. RESULTS: The twenty-seven studies identified were of low and moderate quality, and challenging to synthesize due to inadequate reporting. Findings from six observational studies were mixed but suggest a link between higher serum PTH levels and increased odds of poor cognition or dementia. Two case-control studies of hypoparathyroidism provide limited evidence for a link with poorer cognitive function. Thirteen pre-post surgery studies for primary hyperparathyroidism show mixed evidence for improvements in memory though limited agreement in other cognitive domains. There was some degree of cognitive impairment and improvement postoperatively in observational studies of secondary hyperparathyroidism but no evident pattern of associations with specific cognitive domains. CONCLUSIONS: Mixed evidence offers weak support for a link between PTH, cognition and dementia due to the paucity of high quality research in this area.NIHR PenCLAHRCAlzheimer’s AssociationRosetrees TrustMary Kinross Charitable TrustJames Tudor FoundationHalpin TrustNorman Family Charitable Trus

Making Connections:Social identification with New Treatment Groups for Lifestyle Management of Severe Obesity

Groups are regularly used to deliver healthcare services, including the management of obesity, and there is growing evidence that patients' experiences of such groups fundamentally shape treatment effects. This study investigated factors related to patients' shared social identity formed within the context of a treatment group for the management of severe obesity. A cross-sectional survey was administered to patients registered with a UK medical obesity service and enrolled on a group-based education and support programme. Patients (N=78; MBMI = 48 on entry to the service) completed measures of group demographics (e.g., group membership continuity) and psychosocial variables (e.g., past experiences of weight discrimination), and reported their social identification with the treatment group. The results showed that patients identified with the treatment group to the extent that there was continuity in membership across the programme and they perceived themselves more centrally in terms of their weight status. Weight centrality was negatively associated with external social support and positively associated with experiences of weight discrimination. Group continuity was positively correlated with session attendance frequency. Patients presenting to clinical treatment services with severe obesity often do so after sustained weight loss failure and exposure to negative societal experiences. This study highlights that providing a treatment environment wherein these experiences can be shared with other patients may provide common ground for development of a new, positive social identity that can structure programme engagement and progression

Training response inhibition to food is associated with weight loss and reduced energy intake (dataset)

Full dataset in SPSS and Excel to accompany the manuscript described above.Manuscript available via: https://ore.exeter.ac.uk/repository/handle/10871/17858Dataset to accompany the above manuscript (abstract): The majority of adults in the UK and US are overweight or obese due to multiple factors including excess energy intake. Training people to inhibit simple motor responses (key presses) to high-energy density food pictures reduces intake in laboratory studies. We examined whether online response inhibition training reduced real-world food consumption and weight in a community sample of adults who were predominantly overweight or obese (N = 83). Participants were allocated in a randomised, double-blind design to receive four 10-minute sessions of either active or control go/no-go training in which either high-energy density snack foods (active) or non-food stimuli (control) were associated with no-go signals. Participants’ weight, energy intake (calculated from 24-hour food diaries), daily snacking frequency and subjective food evaluations were measured for one week pre- and post-intervention. Participants also provided self-reported weight and monthly snacking frequency at pre-intervention screening, and one month and six months after completing the study. Participants in the active relative to control condition showed significant weight loss, reductions in daily energy intake and a reduction in rated liking of high-energy density (no-go) foods from the pre- to post-intervention week. There were no changes in self-reported daily snacking frequency. At longer-term follow-up, the active group showed significant reductions in self-reported weight at six months, whilst both groups reported significantly less snacking at one- and six-months. Excellent rates of adherence (97%) and positive feedback about the training suggest that this intervention is acceptable and has the potential to improve public health by reducing energy intake and overweight.Wellcome Trus

Training response inhibition to food is associated with weight loss and reduced energy intake (article)

AcceptedNatalia S Lawrence University of Exeter Psychology Exeter Devon EX4 4QG United KingdomAccompanying dataset available at: http://hdl.handle.net/10871/17621Note to users: Uncorrected proofs are Articles in Press that have been copy edited and formatted, but have not been finalized yet. They still need to be proof-read and corrected by the author(s) and the text could still change before final publication. Although uncorrected proofs do not have all bibliographic details available yet, they can already be cited using the year of online publication and the DOI, as follows: author(s), article title, Publication (year), DOI. Please consult the journal's reference style for the exact appearance of these elements, abbreviation of journal names and use of punctuation. When the final article is assigned to an volumes/issues of the Publication, the Article in Press version will be removed and the final version will appear in the associated published volumes/issues of the Publication. The date the article was first made available online will be carried over.The majority of adults in the UK and US are overweight or obese due to multiple factors including excess energy intake. Training people to inhibit simple motor responses (key presses) to high-energy density food pictures reduces intake in laboratory studies. We examined whether online response inhibition training reduced real-world food consumption and weight in a community sample of adults who were predominantly overweight or obese (N = 83). Participants were allocated in a randomised, double-blind design to receive four 10-minute sessions of either active or control go/no-go training in which either high-energy density snack foods (active) or non-food stimuli (control) were associated with no-go signals. Participants’ weight, energy intake (calculated from 24-hour food diaries), daily snacking frequency and subjective food evaluations were measured for one week pre- and post-intervention. Participants also provided self-reported weight and monthly snacking frequency at pre-intervention screening, and one month and six months after completing the study. Participants in the active relative to control condition showed significant weight loss, reductions in daily energy intake and a reduction in rated liking of high-energy density (no-go) foods from the pre- to post-intervention week. There were no changes in self-reported daily snacking frequency. At longer-term follow-up, the active group showed significant reductions in self-reported weight at six months, whilst both groups reported significantly less snacking at one- and six-months. Excellent rates of adherence (97%) and positive feedback about the training suggest that this intervention is acceptable and has the potential to improve public health by reducing energy intake and overweight.National Institute for Health and Research Exeter Clinical Research FacilityWellcome TrustEuropean Research Counci

Production of fresh probiotic cheese with addition of transglutaminase

Svrha rada bila je istražiti utjecaj probiotičke kulture Lactobacillus acidophilus i enzima transglutaminaze (TG) na kvalitetu i senzorska svojstva autohtonog svježeg sira iz okolice Zagreba. Svježem, nepasteriziranom, obranom mlijeku dodan je enzim transglutaminaza (TG), a na različitim temperaturama i trajanju aktivacije (8 sati na 11 ºC i 4 sata na 25 ºC). Inaktivacija enzima provedena je postupkom pasterizacije (65 ºC/30 min). Nakon hlađenja na 25 ºC, mlijeko za proizvodnju svježeg sira inokulirano je mezofilnom kulturom bakterija mliječne kiseline MM101 i probiotičkom kulturom L. acidophilus LAC-1. Uz pokusne uzorke, s dodatkom TG i probiotičke kulture, proizvedeni su i kontrolni uzorci bez dodatka TG i probiotika te uzorci bez TG, ali uz dodatak probiotika. Uzorci svježeg sira proizvedeni uz dodatak TG, posebno oni gdje je TG djelovala 8 sati na 11 ºC, imali su veću masu od uzoraka proizvedenih bez dodatka enzima, pa je stoga i prinos sira bio veći, a pokazali su i manju sinerezu tijekom 10 dana čuvanja svježeg sira na 10 ºC negoli uzorci koji su proizvedeni bez dodatka enzima. Isti su uzorci dobili najviše ocjene senzorskih svojstava. Metabolička aktivnost mezofilne kulture MM101 i probiotičkog soja L. acidophilus LAC-1 utjecala je na bolji okus i miris svježeg sira, a broj živih stanica probiotičkog soja L. acidophilus LAC-1 u priređenim uzorcima bio je cca 5 x 106 cfu/g nakon 10 dana čuvanja na 10 ºC, što je više od minimalnog preporučenog broja u probiotičkim proizvodima. Dodatak transglutaminaze doprinosi boljoj konzistenciji i općem izgledu svježeg sira.The aim of this research was to examine the influence of probiotic culture Lactobacillus acidophilus and enzyme transglutaminase (TG) on quality and sensory properties of autochthonous fresh cheese from Zagreb region. Fresh, unpasteurized, skimmed milk was inoculated with TG at different temperatures and activation time (8 h at 11 ºC and 4 h at 25 ºC). Inactivation of the enzyme was carried out during the process of pasteurization (65ºC/30 min). The milk for fresh cheese production was further inoculated with mesophilic culture of lactic acid bacteria MM101 and probiotic strain Lactobacillus acidophilus LAC-1. Besides the trial samples with addition of TG and probiotic bacteria, control samples without addition of TG and probiotic were produced, as well as the samples without addition of TG but with probiotic bacteria addition. Samples of fresh cheese produced with addition of TG, especially in which TG was active at 11 ºC, had greater weight then samples produced without the enzyme addition. Therefore, their yield was also greater then yield of cheese produced without the addition of the enzyme. Furthermore, the samples of fresh cheese produced with addition of TG have shown lesser syneresis than other samples during 10 days of storage at 10 ºC. The same samples also had the best sensory properties. Metabolic activity of mesophilic culture MM101 and probiotic culture L. acidophilus LAC-1 has resulted in better taste and odour of fresh cheese. The viable cell number of probiotic strain L. acidophilus LAC-1 in prepared samples was around 5 x 106 cells/g after 10 days of storage at 10 ºC, which is higher than the minimal dose required for 27 probiotic products. Addition of transgultaminase contributed to better consistency and general appearance of produced fresh cheese

Production of fresh probiotic cheese with addition of transglutaminase

Svrha rada bila je istražiti utjecaj probiotičke kulture Lactobacillus acidophilus i enzima transglutaminaze (TG) na kvalitetu i senzorska svojstva autohtonog svježeg sira iz okolice Zagreba. Svježem, nepasteriziranom, obranom mlijeku dodan je enzim transglutaminaza (TG), a na različitim temperaturama i trajanju aktivacije (8 sati na 11 ºC i 4 sata na 25 ºC). Inaktivacija enzima provedena je postupkom pasterizacije (65 ºC/30 min). Nakon hlađenja na 25 ºC, mlijeko za proizvodnju svježeg sira inokulirano je mezofilnom kulturom bakterija mliječne kiseline MM101 i probiotičkom kulturom L. acidophilus LAC-1. Uz pokusne uzorke, s dodatkom TG i probiotičke kulture, proizvedeni su i kontrolni uzorci bez dodatka TG i probiotika te uzorci bez TG, ali uz dodatak probiotika. Uzorci svježeg sira proizvedeni uz dodatak TG, posebno oni gdje je TG djelovala 8 sati na 11 ºC, imali su veću masu od uzoraka proizvedenih bez dodatka enzima, pa je stoga i prinos sira bio veći, a pokazali su i manju sinerezu tijekom 10 dana čuvanja svježeg sira na 10 ºC negoli uzorci koji su proizvedeni bez dodatka enzima. Isti su uzorci dobili najviše ocjene senzorskih svojstava. Metabolička aktivnost mezofilne kulture MM101 i probiotičkog soja L. acidophilus LAC-1 utjecala je na bolji okus i miris svježeg sira, a broj živih stanica probiotičkog soja L. acidophilus LAC-1 u priređenim uzorcima bio je cca 5 x 106 cfu/g nakon 10 dana čuvanja na 10 ºC, što je više od minimalnog preporučenog broja u probiotičkim proizvodima. Dodatak transglutaminaze doprinosi boljoj konzistenciji i općem izgledu svježeg sira.The aim of this research was to examine the influence of probiotic culture Lactobacillus acidophilus and enzyme transglutaminase (TG) on quality and sensory properties of autochthonous fresh cheese from Zagreb region. Fresh, unpasteurized, skimmed milk was inoculated with TG at different temperatures and activation time (8 h at 11 ºC and 4 h at 25 ºC). Inactivation of the enzyme was carried out during the process of pasteurization (65ºC/30 min). The milk for fresh cheese production was further inoculated with mesophilic culture of lactic acid bacteria MM101 and probiotic strain Lactobacillus acidophilus LAC-1. Besides the trial samples with addition of TG and probiotic bacteria, control samples without addition of TG and probiotic were produced, as well as the samples without addition of TG but with probiotic bacteria addition. Samples of fresh cheese produced with addition of TG, especially in which TG was active at 11 ºC, had greater weight then samples produced without the enzyme addition. Therefore, their yield was also greater then yield of cheese produced without the addition of the enzyme. Furthermore, the samples of fresh cheese produced with addition of TG have shown lesser syneresis than other samples during 10 days of storage at 10 ºC. The same samples also had the best sensory properties. Metabolic activity of mesophilic culture MM101 and probiotic culture L. acidophilus LAC-1 has resulted in better taste and odour of fresh cheese. The viable cell number of probiotic strain L. acidophilus LAC-1 in prepared samples was around 5 x 106 cells/g after 10 days of storage at 10 ºC, which is higher than the minimal dose required for 27 probiotic products. Addition of transgultaminase contributed to better consistency and general appearance of produced fresh cheese