Postprandial adiponectin levels are unlikely to contribute to the pathogenesis of obesity in Prader-Willi syndrome

AIM: To investigate fasting and postprandial adiponectin levels in PWS patients as compared to obese and lean subjects and whether they could contribute to the pathogenesis of obesity in this syndrome. METHODS: We studied 7 patients with PWS, 16 obese patients and 42 lean subjects for the fasting study. From this group, we evaluated 7 patients with PWS, 7 age-sex-BMI-matched obese non-PWS patients and 7 age-sex-matched lean subjects before and after the administration of 3,139.5 kJ (750 kcal) of a standard liquid meal (53.2% carbohydrate, 30% fat, 16.7% protein) after an overnight fast. Blood samples were obtained every 15 min for the first hour and every 30 min thereafter until 6 h. Adiponectin, IGF-I, glucose, triglycerides, cholesterol, and insulin were measured. RESULTS: Fasting plasma adiponectin levels were lower in PWS than in lean subjects (5.24+/-2.56 vs. 8.28+/-4.63 microg/ml, p=0.041) but higher than in obese patients (4.01+/-1.27 microg/ml, p=0.047). After the meal, adiponectin concentrations mildly decreased in PWS at time point 240 min, while in obese and lean subjects no changes were observed. However, 6-hour postprandial AUC for adiponectin was similar in all three groups. CONCLUSION: Fasting adiponectin levels are low in PWS, but they are so mildly modulated postprandially that these changes do not seem significant for the pathogenesis of obesity in this syndrome.     

Effectiveness of a Multi-Component Intervention for Overweight and Obese Children (Nereu Program): A Randomized Controlled Trial

Introduction

Treatment of childhood obesity is a complex challenge for primary health care professionals.

Objectives

To evaluate the effectiveness of the Nereu Program in improving anthropometric parameters, physical activity and sedentary behaviours, and dietary intake.

Methods

Randomized, controlled, multicentre clinical trial comparing Nereu Program and usual counselling group interventions in primary care settings. The 8-month study recruited 113 children aged 6 to 12 years with overweight/obesity. Before recruitment, eligible participants were randomly allocated to an intensive, family-based multi-component behavioural intervention (Nereu Program group) or usual advice from their paediatrician on healthy eating and physical activity. Anthropometric parameters, objectively measured sedentary and physical activity behaviours, and dietary intake were evaluated pre- and post-intervention.

Results

At the end of the study period, both groups achieved a similar decrease in body mass index (BMIsd) compared to baseline. Nereu Program participants (n = 54) showed greater increases in moderate-intense physical activity (+6.27% vs. -0.61%, p<0.001) and daily fruit servings (+0.62 vs. +0.13, p<0.026), and decreased daily soft drinks consumption (-0.26 vs. -0.02, p<0.047), respectively, compared to the counselling group (n = 59).

Conclusions

At the end of the 8-month intervention, participants in the Nereu Program group showed improvement in physical activity and dietary behaviours, compared to the counselling group.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01878994","term_id":"NCT01878994"}}NCT01878994     

Fatty acid-binding protein-hormone-sensitive lipase interaction. Fatty acid dependence on binding

Adipose lipolysis is mediated, in part, via interaction of fatty acid-binding protein (FABP) with hormone-sensitive lipase (HSL). Mice with reduced FABP content in fat (adipocyte FABP null) exhibit diminished fat cell lipolysis, whereas transgenic mice with increased FABP content in fat (epithelial FABP transgenic) exhibit enhanced lipolysis. To examine the relationship between the binding of FABP to HSL and activation of catalytic activity, isothermal titration microcalorimetry as well as kinetic analysis using a variety of FABP isoforms have been employed. In the absence of fatty acids, no FABP-HSL association could be demonstrated for any FABP form. However, in the presence of 10 microm oleate, A-FABP and E-FABP each bound to HSL with high affinity (Kd of 0.5 and 3 nM, respectively) in a approximately 1:1 molar stoichiometry, whereas liver FABP and intestinal FABP did not exhibit any association. To compare binding to catalysis, each FABP isoform was incubated with HSL in vitro, and enzymatic activity was assessed. Importantly, each FABP form stimulated HSL activity approximately 2-fold using cholesteryl oleate as substrate but exhibited no activation using p-nitrophenyl butyrate. The activation by A-FABP was dependent upon its fatty acid binding properties because a non-fatty acid binding mutant, R126Q, failed to activate HSL. These results suggest that binding and activation of HSL by FABPs are separate and distinct functions and that HSL contains a site for fatty acid binding that allows for FABP association.     

Stereoselective inhibition of rat brain cyclooxygenase by dexketoprofen

Although it has been assumed that the effects of nonsteroidal antiinflammatory drugs (NSAIDs) are mainly the result of their action on local synthesis of prostaglandins, there is growing evidence to suggest that they may also exert a central analgesic action. Some authors have suggested that inhibition of prostaglandin synthesis in the brain could contribute to the analgesic action. The effect of dexketoprofen trometamol (tromethamine salt of the enantiomer (+)-S-ketoprofen) on prostaglandin synthesis was investigated in rat brain fragments and in cyclooxygenase preparations from rat brain microsomes. Effects of the (-)-R-enantiomer and the racemic mixture were also evaluated. Significant levels of prostaglandin F_2α (PGF_2α) were synthesized in rat brain fragments after 10 min of incubation at 37°C. Dexketoprofen was found to be a potent inhibitor of this PGF_2α production in rat brain (IC₅₀ = 6.2 nM), and it completely suppressed PGF_2α production at 1 μM concentration. In addition, inhibition of PGF_2α synthesis by dexketoprofen was highly stereoselective since the enantiomer (-)-R-ketoprofen was significantly less potent (IC₅₀ = 294 nM); with this enantiomer, even at high concentrations such as 1 μM, less than 60% inhibition was achieved. These results correlated with those obtained in the study of racemic ketoprofen and its enantiomers on cyclooxygenase activity of rat brain microsomes, where dexketoprofen also inhibited enzymatic activity stereoselectively. IC₅₀ values obtained for dexketoprofen, (-)-R-ketoprofen, and rac-ketoprofen were 3.5 μM, 45.3 μM, and 5.8 μM, respectively. The above results could be related to the potent analgesic effect of dexketoprofen observed in vivo, which was also stereoselective. Taken together, these findings suggest that prostaglandin synthesis inhibition in rat brain by dexketoprofen could be associated, at least in part, with the analgesic effect of this NSAID. Chirality 9:281–285, 1997. © 1997 Wiley-Liss, Inc.     

The practical challenges of evaluating a blanket emergency feeding programme in northern Kenya

A blanket supplementary feeding programme for young children was implemented for four months in five northern districts of Kenya from January 2010 because of fears of food insecurity exacerbated by drought. An attempt to evaluate the impact of the food on children's anthropometric status was put in place in three districts. The main aim of the analysis was to assess the quality of the data on the cohort of children studied in the evaluation and to propose methods by which it could be improved to evaluate future blanket feeding programmes. Data on the name, age, sex, weight and height of a systematic sample of children recruited at 61 food distribution sites were collected at the first, second and third rounds and again at an extra, fifth food distribution, offered only to the evaluation subjects. Of the 3,544 children enrolled, 483 (13.63%) did not collect a fifth ration. Of the 2,640 children who were considered by their name to be the same at the first and fifth food distribution (13% were different), data on only 902 children (34.17%) were considered acceptable based on their age (an arbitrary ±3 months different) and their length or height (between >-1 or ≤4 cm different) at the two instances they were seen. Data on nearly two thirds of children were of questionable quality. The main reasons for the poor quality data were inconsistencies in estimating age or because caretakers may have brought different children. Recommendations are made about how to improve data quality including ensuring that entry to a blanket feeding programme is clearly based on height, not age, to avoid misreporting age; careful identification of subjects at all contacts; and using well-trained, specialist evaluation staff.     

Stereoselective metabolic pathways of ketoprofen in the rat: Incorporation into triacylglycerols and enantiomeric inversion

The enantiomeric bioinversion of ketoprofen (KP) enantiomers and their incorporation into triacylglycerols were investigated in the rat (1) in vitro, using liver homogenates, subcellular fractions, and hepatocytes, and (2) in vivo, in different tissue samples after oral administration of the radiolabelled compounds. In liver homogenates or subcellular fractions, the enantiomer (S)-ketoprofen (S-KP) was recovered unchanged, whereas (R)-ketoprofen (R-KP) was partially converted into its Coenzyme A (CoA) thioester and inverted to S-KP. Both processes occurred mainly in the mitochondrial fraction. This supports the mechanism of inversion via stereoselective formation of CoA thioesters of R-KP, already described for other non-steroidal anti-inflammatory drugs. Incorporation into triacylglycerols was detected after incubation with intact hepatocytes in the presence of added glycerol. The process was stereoselective for R-KP vs. S-KP (covalently bound radioactivity 26,742 ± 4,665 dpm/10⁶ cells vs. 6,644 ± 3,179 dpm/10⁶ cells, respectively). However, no incorporation was found in liver samples after oral administration of either R-KP or S-KP. On the contrary, in adipose tissue samples a significant and stereoselective formation of hybrid triacylglycerols was observed: 11,076 ± 2,790 dpm.g⁻¹ for R-KP vs. 660 ± 268 dpm.g⁻¹ for S-KP. The incorporated R/S ratio, higher in adipose tissue (R/S = 17) than in hepatocytes (R/S = 4), indicates that fat may be the main tissue store for the xenobiotic R-KP in rats. © 1996 Wiley-Liss, Inc.     

Differential hydrolysis of 1-alkyl-2-acyl and diacylglycerophosphocholines by human and non-human phospholipases A2.

The activity of two human phospholipases A2, purified from synovial fluid and lumbar disc herniations, was tested using alkylacyl- and diacylglycerophosphocholines and the influence of the chemical link at the sn-1 position of glycerol was investigated. Both enzymes exhibited 2.5-3-fold selectivity for 1-ester-linked compared to 1-ether-linked phosphatidylcholine. No significant selectivity was observed with pancreatic phospholipase A2 while Naja naja naja venom enzyme was more efficient against 1-ether-phospholipids.     

Increased lipolysis in transgenic animals overexpressing the epithelial fatty acid binding protein in adipose cells

Fatty acid binding proteins (FABPs) are low-molecular-mass, soluble, intracellular lipid carriers. Previous studies on adipocytes from adipocyte fatty acid binding protein (A-FABP)-deficient mice have revealed that both basal and isoproterenol-stimulated lipolysis were markedly reduced (Coe et al. 1999. J. Lipid Res. 40: 967-972). Herein, we report the construction of transgenic mice overexpressing the FABP5 gene encoding the epithelial fatty acid binding protein (E-FABP) in adipocytes, thereby allowing evaluation of the effects on lipolysis of increased FABP levels and of type specificity. In adipocytes from FABP5 transgenic mice, the total FABP protein level in the adipocyte was increased to 150% as compared to the wild type due to a 10-fold increase in the level of E-FABP and an unanticipated 2-fold down-regulation of the A-FABP. There were no significant differences in body weight, serum FFA, or fat pad mass between wild-type and FABP5 transgenic mice. Importantly, both basal and hormone-stimulated lipolysis increased in adipocytes from the FABP5 transgenic animals. The molecular composition of the fatty acid pool from either the intracellular compartment or that effluxed from the adipocyte was unaltered. These results demonstrate that there is a positive relationship between lipolysis and the total level of FABP but not between lipolysis and a specific FABP type.     

Immunolocalisation of P2Y receptors in the rat eye

Nucleotides present an important role in ocular physiology which has been demonstrated by recent works that indicate their involvement in many ocular processes. P2Y are important among P2 receptors since they can control tear production, corneal wound healing, aqueous humour dynamics and retinal physiology. Commercial antibodies have allowed us to investigate the distribution of P2Y receptors in the cornea, anterior and posterior chamber of the eye and retina. The P2Y₁ receptor was present mainly in cornea, ciliary processes, and trabecular meshwork. The P2Y₂ receptors were present in cornea, ciliary processes and retinal pigmented epithelium. P2Y₄ was present in cornea, ciliary processes, photoreceptors, outer plexiform layer and ganglion cell layer. The P2Y₆ presented almost an identical distribution as the P2Y₄ receptor. The P2Y₁₁ was also detectable in the retinal pigmented epithelium. The detailed distribution of the receptors clearly supports the recent findings indicating the relevant role of nucleotides in the ocular function.