Inhibition of food intake in obese subjects by peptide YY3-36

Background: The gut hormone fragment peptide YY3-36 (PYY) reduces appetite and food intake when infused into subjects of normal weight. In common with the adipocyte hormone leptin, PYY reduces food intake by modulating appetite circuits in the hypothalamus. However, in obesity there is a marked resistance to the action of leptin, which greatly limits its therapeutic effectiveness. We investigated whether obese subjects were also resistant to the anorectic effects of PYY.Methods: We compared the effects of PYY infusion on appetite and food intake in 12 obese and 12 lean subjects in a double-blind, placebo-controlled, crossover study. The plasma levels of PYY, ghrelin, leptin, and insulin were also determined.Results: Caloric intake during a buffet lunch offered two hours after the infusion of PYY was decreased by 30 percent in the obese subjects (P<0.001) and 31 percent in the lean subjects (P<0.001). PYY infusion also caused a significant decrease in the cumulative 24-hour caloric intake in both obese and lean subjects. PYY infusion reduced plasma levels of the appetite-stimulatory hormone ghrelin. Endogenous fasting and postprandial levels of PYY were significantly lower in obese subjects (the mean [+/-SE] fasting PYY levels were 10.2+/-0.7 pmol per liter in the obese group and 16.9+/-0.8 pmol per liter in the lean group, P<0.001). Furthermore, the fasting PYY levels correlated negatively with the body-mass index (r=-0.84, P<0.001).Conclusions: We found that obese subjects were not resistant to the anorectic effects of PYY. Endogenous PYY levels were low in the obese subjects, suggesting that PYY deficiency may contribute to the pathogenesis of obesity

Diagnosis of dihydropyrimidinase deficiency in a Chinese boy with dihydropyrimidinuria

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Semaphorin3A, associated with perineuronal nets, regulates the development of the maturation of the central vestibular circuitry

Poster Presentation - Theme 5: NeuroscienceDuring the formative period of neural circuits, perineuronal nets (PN) are established to restrict plasticity of the circuit. The role of PN in vestibular plasticity can be tested by studying the emergence of negative geotaxis with postnatal maturation of the vestibular circuitry for gravity detection. Using rats as model, we observed that negative geotaxis was mature by postnatal day (P) 9, in correlation with consolidation of PN around GABAergic neurons …postprin

Perineuronal chondroitin sulfates and semaphorin 3A regulate postnatal maturation of the vestibular circuit for gravity detection

Conference Theme: The Extracellular Matrix NichePoster Presentation: abstract no. P30Perineuronal chondroitin sulfate proteoglycan networks are implicated in restricting plasticity of the mature CNS. Less is known of the impact of ligands associated with the perineuronal network (PN) in the formative period of neural circuits. The emergence of negative geotaxis with postnatal maturation of the vestibular circuitry for gravity detection offers a behavioral readout in tests for roles of the PN and associated ligands in vestibular plasticity. Using postnatal rats as model, we found that negative geotaxis was mature by postnatal day (P) 9, in correlation with ...postprin

Methodology for the evaluation of yield strength and hardening behavior of metallic materials by indentation with spherical tip

Author name used in this publication: Chung Wo Ong2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Towards green energy for smart cities: particle swarm optimization based MPPT approach

This paper proposes an improved one-power-point (OPP) maximum power point tracking (MPPT) algorithm for wind energy conversion system (WECS) to overcome the problems of the conventional OPP MPPT algorithm, namely, the difficulty in getting a precise value of the optimum coefficient, requiring pre-knowledge of system parameters, and non-uniqueness of the optimum curve. The solution is based on combining the particle swarm optimization (PSO) and optimum-relation-based (ORB) MPPT algorithms. The PSO MPPT algorithm is used to search for the optimum coefficient. Once the optimum coefficient is obtained, the proposed algorithm switches to the ORB MPPT mode of operation. The proposed algorithm neither requires knowledge of system parameters nor mechanical sensors. In addition, it improves the efficiency of the WECS. The proposed algorithm is studied for two different wind speed profiles, and its tracking performance is compared with conventional optimum torque control (OTC) and conventional ORB MPPT algorithms under identical conditions. The improved performance of the algorithm in terms of tracking efficiency is validated through simulation using MATLAB/Simulink. The simulation results confirm that the proposed algorithm has a better performance in terms of tracking efficiency and energy extracted. The tracking efficiency of the PSO-ORB MPPT algorithm could reach up to 99.4% with 1.9% more harvested electrical energy than the conventional OTC and ORB MPPT algorithms. Experiments have been carried out to demonstrate the validity of the proposed MPPT algorithm. The experimental results compare well with system simulation results, and the proposed algorithm performs well, as expected

Inhibition of prostate cancer cell growth by human secreted PDZ domain-containing protein 2, a potential autocrine prostate tumor suppressor

A possible role of the PDZ domain-containing protein 2 (PDZD2) in prostate tumorigenesis has been suggested. Besides, PDZD2 is posttranslationally cleaved by a caspase-dependent mechanism to form a secreted PDZ domain-containing protein 2 (sPDZD2) with unknown functions in humans. In this study, we demonstrate the endogenous expression of PDZD2 and secretion of sPDZD2 in cancerous DU145, PC-3, 22Rv1, LNCaP, and immortalized RWPE-1 prostate epithelial cells. Inhibition of endogenous sPDZD2 production and secretion by DU145, PC-3, 22Rv1, and RWPE-1 cells via the caspase-3 inhibitor Z-DEVD-FMK resulted in increased cell proliferation, which was abrogated by treatment with exogenous recombinant sPDZD2. Whereas sPDZD2-induced antiproliferation in DU145, PC-3, and 22Rv1 cells, it induced apoptosis in LNCaP cells. The data suggest that endogenous sPDZD2, produced by caspase-3-mediated cleavage from PDZD2, may function as a novel autocrine growth suppressor for human prostate cancer cells. The antiproliferative effect of sPDZD2 was apparently mediated through slowing the entry of DU145, PC-3, and 22Rv1 cells into the S phase of the cell cycle. In DU145 cells, this can be attributed to stimulated p53 and p21 CIP1/WAF1 expression by sPDZD2. On the other hand, the apoptotic effect of sPDZD2 on LNCaP cells was apparently mediated via p53-independent Bad stimulation. Together our results indicate the presence of p53-dependent and p53-independent PDZD2/sPDZD2 autocrine growth suppressive signaling pathways in human prostate cancer cells and suggest a novel therapeutic approach of harnessing the latent tumor-suppressive potential of an endogenous autocrine signaling protein like sPDZD2 to inhibit prostate cancer growth. Copyright © 2006 by The Endocrine Society.postprin

The role of proheparanase in synaptic plasticity at the hippocampus

Abstract no. P-110Perineuronal heparan sulfate (HS) moieties are implicated in the modulation of neurotransmission by controlling the functional properties of AMPA-type glutamate receptors. We hypothesize that neuronal mechanisms modulate peri-synaptic HS level, thereby regulating synaptic strength and plasticity. To address this, basal synaptic strength and long-term changes in synaptic efficacy in the Schaffer collateral pathway of the rat hippocampus were assessed in relation to strategies that perturb peri-synaptic HS. In hippocampal slices, heparitinase treatment led to dose-dependent attenuation of long-term potentiation (LTP) in correlation with loss of perineuronal HS …postprin

Regulatory role of proheparanase with peri-synaptic heparan sulfate proteoglycan and AMPA-type glutamate receptor in synaptic plasticity

Poster Presentation: P59AMPA-type glutamate receptors (AMPAR) govern excitatory synaptic transmission. Perineuronal heparan sulfates (HS) have been implicated in controlling the open-state of AMPAR. Our finding of neuronal heparanase expression in adult rats led us to test (1) if neuronal heparanase is secreted and (2) if the secreted form acts on perineuronal HS to modulate synaptic plasticity. Neuronal secretion of heparanase was triggered by phorbol ester of rat hippocampal neurons in culture. Western blot analysis of the secreted product revealed enzymatically inactive proheparanase, but not the enzymatically active heparanase. Synaptosomes prepared from phorbol ester-treated rat cortexslices showed enrichment in proheparanase; co-immunoprecipitation studies further showed association of AMPAR subunits (GluA1 and GluA2/3) with both syndecan-3 (a transmembrane HS-proteoglycan) and proheparanase, suggesting their partnership in the peri-synaptic environment. Treatment of hippocampal neurons in culture with recombinant proheparanase triggered internalization of proheparanase, perineuronal HS-proteoglycans and AMPARs, suggesting their clustering as a functional complex. Heparitinase pre-treatment of hippocampal neuron cultures reduced proheparanase-induced internalization of AMPARs, suggesting that the HS moiety is critical for effecting the partnership. Treatment of hippocampal slices with recombinant proheparanase resulted in down-regulation of both basal synaptic strength and LTP at Schaffer collateral synapses. These results reveal a novel role of neuronal proheparanase in resetting AMPAR and perineuronal HS levels at the synapse and thus the modulation of synaptic plasticity.postprin

Physicochemical and sensory properties of pawpaw (Carica papaya Linn) flavoured yoghurt

Flavoured yoghurts are widely produced by using synthetic flavourings in Cameroon.However, the addition of fruits to yoghurt will impart natural flavours as well ascontribute to the welfare of consumers by enhancing the nutritive and the functionalproperties of the yoghurt. This study was, therefore, aimed at evaluating thephysicochemical and sensory properties of pawpaw (Carica papaya L.) flavouredyoghurt. Yoghurt was produced with the incorporation of pawpaw puree at four levels:0% (P0 as control), 5% (P1), 10% (P2) and 15% (P3). The yoghurt samples weresubmitted to some physicochemical analysis (pH, titratable acidity, dry matter,moisture content, fat content, Solid-Non-Fat (SNF), sugar content and viscosity) ondays 0, 7, 14, and 21 of storage. The sensory characteristics assessed by an untrainedpanel of 30 members were: flavour, colour, taste and texture. The pH of P0 (5.01±0.04)and P3(4.99±0.04) and also the fat content of P0 (3.4±0.17%) were significantly(P≤0.05) higher compared to other samples. There was a reduction of fat content inyoghurt with an increase of pawpaw puree. Sugar content, SNF and viscosity ofyoghurt increased significantly (P≤0.05) with addition of pawpaw puree. Meanwhile,dry matter and titratable acidity were not significantly (P≥0.05) affected. The titratableacidity of yoghurt P0 and P3 significantly (P≤0.05) increased up to day seven of storagewhile pH was decreasing. From days 14 to 21, yoghurt P2 and yoghurts P2 and P3 didnot present significant (P≥0.05) decrease of titratable acidity and pH, respectively. Thefat content of P0 and P1, reduced significantly (P≤0.05) the first week and the secondweeks of storage, respectively, and then remained comparable (P≥0.05) to the end ofthe storage period. There was no significant (P≥0.05) difference in sensory propertiesof all the yoghurt treatments. In conclusion, the use of pawpaw to flavour yoghurt didnot negatively affect the yoghurt properties; therefore, pawpaw flavoured yoghurt canbe recommended for consumption.Keys words: Flavoured yoghurt, pawpaw puree, physicochemical properties, storage,sensory propertie