910 resultados para Games not play


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Platelets release glutamate upon activation and are an important clearance system of the amino acid from blood, through high-affinity glutamate uptake, similar to that described in brain synaptosomes. Since platelet glutamate uptake is decreased in neurodegenerative disorders, we performed a morphological and molecular characterization of platelet glutamate transporters. The three major brain glutamate transporters EAAT1, EAAT2 and EAAT3 are expressed in platelets, with similar molecular weight, although at lower density than brain. A Na(+)-dependent-high-affinity glutamate uptake was competitively inhibited by known inhibitors but not by dihydrokainic acid, suggesting platelet EAAT2 does not play a major role in glutamate uptake at physiological conditions. We observed decreased glutamate uptake V(max), without modification of transporter affinity, in aging, which could be linked to the selective decrease of EAAT1 expression and mRNA. Moreover, in AD patients we found a further EAAT1 reduction compared to age-matched controls, which could explain the decrease of platelet uptake previously described. Platelet glutamate transporters may be used as peripheral markers to investigate the role of glutamate in patients with neuropsychiatric disorders.

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First-principles calculations of the Sigma 5(310)[001] symmetric tilt grain boundary in Cu with Bi, Na, and Ag substitutional impurities provide evidence that in the phenomenon of Bi embrittlement of Cu grain boundaries electronic effects do not play a major role; on the contrary, the embrittlement is mostly a structural or "size" effect. Na is predicted to be nearly as good an embrittler as Bi, whereas Ag does not embrittle the boundary in agreement with experiment. While we reject the prevailing view that "electronic" effects (i.e., charge transfer) are responsible for embrittlement, we do not exclude the role of chemistry. However, numerical results show a striking equivalence between the alkali metal Na and the semimetal Bi, small differences being accounted for by their contrasting "size" and "softness" (defined here). In order to separate structural and chemical effects unambiguously if not uniquely, we model the embrittlement process by taking the system of grain boundary and free surfaces through a sequence of precisely defined gedanken processes; each of these representing a putative mechanism. We thereby identify three mechanisms of embrittlement by substitutional impurities, two of which survive in the case of embrittlement or cohesion enhancement by interstitials. Two of the three are purely structural and the third contains both structural and chemical elements that by their very nature cannot be further unraveled. We are able to take the systems we study through each of these stages by explicit computer simulations and assess the contribution of each to the net reduction in intergranular cohesion. The conclusion we reach is that embrittlement by both Bi and Na is almost exclusively structural in origin; that is, the embrittlement is a size effect.

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Introduction: Cyclooxygenase (COX)-2 influences cardiovascular disease and serum concentration of high-sensitivity C-reactive protein (hsCRP). The study purpose was to determine the influence of single nucleotide polymorphisms (SNPs) of the COX-2 gene on abdominal aortic aneurysm (AAA) development and serum hsCRP concentrations. Patients and Methods: Patients with AAA and disease-free controls were recruited. High-sensitivity C-reactive protein was measured by an enzyme-linked immunosorbent assay (ELISA) test. The distributions of COX-2 SNPs were investigated (rs20417 and rs4648307). The influence of the COX-2 SNPs on the hsCRP serum concentration was assessed.Results: A total of 230 patients with AAA and 279 controls were included. No difference was found in the genotype distribution of the COX-2 SNPs rs20417 (P = .26) and rs4648307 (P = .90). They did not influence the hsCRP concentration (P = .24 and P = .61, respectively). Haplotype analysis of COX-2 SNPs revealed no difference. Conclusion: These COX-2 SNPs do not play any role in AAA development and do not influence serum hsCRP. These results differentiate AAA development from atherosclerotic diseases.

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Objective: To compare trends in breast cancer mortality within three pairs of neighbouring European countries in relation to implementation of screening. Design: Retrospective trend analysis.
Setting: Three country pairs (Northern Ireland (United Kingdom) v Republic of Ireland, the Netherlands v Belgium and Flanders (Belgian region south of the Netherlands), and Sweden v Norway).
Data sources: WHO mortality database on cause of death and data sources on mammography screening, cancer treatment, and risk factors for breast cancer mortality.
Main outcome measures: Changes in breast cancer mortality calculated from linear regressions of log transformed, age adjusted death rates. Joinpoint analysis was used to identify the year when trends in mortality for all ages began to change.
Results: From 1989 to 2006, deaths from breast cancer decreased by 29% in Northern Ireland and by 26% in the Republic of Ireland; by 25% in the Netherlands and by 20% in Belgium and 25% in Flanders; and by 16% in Sweden and by 24% in Norway. The time trend and year of downward inflexion were similar between Northern Ireland and the Republic of Ireland and between the Netherlands and Flanders. In Sweden, mortality rates have steadily decreased since 1972, with no downward inflexion until 2006. Countries of each pair had similar healthcare services and prevalence of risk factors for breast cancer mortality but differing implementation of mammography screening, with a gap of about 10-15 years.
Conclusions: The contrast between the time differences in implementation of mammography screening and the similarity in reductions in mortality between the country pairs suggest that screening did not play a direct part in the reductions in breast cancer mortality.

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The innate immune system plays a critical role in the defense of areas exposed to microorganisms. There is an increasing body of evidence indicating that antimicrobial peptides and proteins (APs) are one of the most important weapons of this system and that they make up the protective front for the respiratory tract. On the other hand, it is known that pathogenic organisms have developed countermeasures to resist these agents such as reducing the net negative charge of the bacterial membranes. Here we report the characterization of a novel mechanism of resistance to APs that is dependent on the bacterial capsule polysaccharide (CPS). Klebsiella pneumoniae CPS mutant was more sensitive than the wild type to human neutrophil defensin 1, beta-defensin 1, lactoferrin, protamine sulfate, and polymyxin B. K. pneumoniae lipopolysaccharide O antigen did not play an important role in AP resistance, and CPS was the only factor conferring protection against polymyxin B in strains lacking O antigen. In addition, we found a significant correlation between the amount of CPS expressed by a given strain and the resistance to polymyxin B. We also showed that K. pneumoniae CPS mutant bound more polymyxin B than the wild-type strain with a concomitant increased in the self-promoted pathway. Taken together, our results suggest that CPS protects bacteria by limiting the interaction of APs with the surface. Finally, we report that K. pneumoniae increased the amount of CPS and upregulated cps transcription when grown in the presence of polymyxin B and lactoferrin.

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Aim: To evaluate the distribution of fundus autofluorescence in patients with age-related macular degeneration and choroidal neovascularisation (CNV). Methods: Colour fundus photographs, fundus fluorescein angiograms (FFA) and fundus autofluorescence images were obtained from a group of 40 patients (43 eyes) with age-related macular degeneration and purely classic or occult CNV. Only patients with newly diagnosed CNV and in whom autofluorescence images were obtained within 2 weeks from FFA were included. The distribution of autofluorescence was qualitatively evaluated, and the findings compared with those from colour fundus photographs and FFA. Results: 29 (67%) eyes had classic CNV and 14 (33%) had occult CNV. In 26 (90%) eyes with classic CNV, a low autofluorescence signal was detected at the site of the CNV; in 7 (50%) eyes with occult CNV, multiple foci of low autofluorescence signal were detected. Outside the area affected by the lesion, homogeneous autofluorescence was observed in most of the cases (n = 33, 77%). Similarly, homogeneous autofluorescence was commonly observed in fellow eyes (62%). A pattern of focal increased autofluorescence was rarely seen in eyes with CNV (n = 4, 9%) or in fellow eyes (n = 4, 15%). In 11 of 43 (25%) eyes, areas of increased autofluorescence, other than a pattern of focal increased autofluorescence, were detected. In four patients, autofluorescence images had been obtained before the development of CNV; in none was any increased autofluorescence detected before the formation of CNV. Conclusions: Distinct patterns of autofluorescence were observed in eyes with pure classic and occult CNV. Increased autofluorescence was rarely seen in eyes with CNV and in fellow eyes, suggesting that increased autofluorescence, and thus, retinal pigment epithelium lipofuscin, may not play an essential part in the formation of CNV.

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Geo-synthetic reinforcements are often used to enhance the stability of geotechnical structures such as embankments. These geosynthetic polymers often show significant creep deformational behaviour. In the short-term performance of a geotechnical structure, it may not play a significant role. However, while dealing with the long term behaviour, it is necessary to investigate its effect. In this paper two plane strain fully coupled finite element analysis have been conducted; one with and the other without taking into account of the creep behaviour of geosynthetics. A well documented field case of Leneghans embankment (Geogrid improved wide embankment constructed near Sydney, Australia in 1990s) have been used for this purpose. It is evident from the analyses that though the geosynthetic reinforcements may play a vital role in the performance/stability of an embankment in the early days (during and after construction), its contribution may become insignificant with time and the creep of geo-synthetic may not play a significant role in the long term stability. © 2012 American Society of Civil Engineers.

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Klebsiella pneumoniae is etiologic agent of community-acquired and nosocomial pneumonia. It has been shown that K. pneumoniae infections are characterized by reduced early inflammatory response. Recently our group have shown that K. pneumoniae dampens the activation of inflammatory responses by antagonizing the activation of the NF-κB canonical pathway. Our results revealed that K. pneumoniae capsule (CPS) was necessary but not sufficient to attenuate inflammation. To identify additional Klebsiella factors required to dampen inflammation, we standardized and applied a high-throughput gain-on-function screen to examine a Klebsiella transposon mutant library. We identified 114 mutants that triggered the activation of NF-κB. Two gene ontology categories accounted for half of the loci identified in the screening, that of metabolism and transport (32% of the mutants), and of enveloperelated genes (17%). Characterization of the mutants revealed that the lack of the enterobactin siderophore was linked to a reduced CPS expression which in turn underlined the NF- κB activation induced by the mutant. The lipopolysaccharide (LPS) O-polysaccharide and the pullulanase (PulA) type 2 secretion system (T2SS) are required for full effectiveness of immune evasion. Importantly, these factors do not play a redundant role. The fact that LPS Opolysaccharide and T2SS mutants-induced responses were dependent on TLR2-TLR4- MyD88 activation suggested that LPS Opolysaccharide and PulA perturbed TLRdependent recognition of K. pneumoniae. Finally, we demonstrate that LPS O-polysaccharide and pulA mutants are attenuated in the pneumonia mouse model. We propose that LPS Opolysaccharide and PulA T2SS could be new targets for designing new antimicrobials. Increasing TLR-governed defence responses might provide also selective alternatives for the management of K. pneumoniae pneumonia.

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Background: Outwith clinical trials, patient outcomes specifically related to SACT (systemic anti-cancer therapy) are not well reported despite a significant proportion of patients receiving active treatment at the end of life. The NCEPOD reviewing deaths within 30 days of SACT found SACT caused or hastened death in 27% of cases.

Method: Across the Northern Ireland cancer network, 95 patients who died within 30 days of SACT for solid tumours were discussed at the Morbidity and Mortality monthly meeting during 2013. Using a structured template, each case was independently reviewed, with particular focus on whether SACT caused or hastened death.

Results: Lung, GI and breast cancers were the most common sites. Performance status was recorded in 92% at time of final SACT cycle (ECOG PS 0-2 89%).

In 57% the cause of death was progressive disease. Other causes included thromboembolism (13%) and infection (5% neutropenic sepsis, 6% non-neutropenic sepsis). In 26% with death from progressive disease, the patient was first cycle of first line treatment for metastatic disease. In the majority discussion regarding treatment aims and risks was documented. Only one patient was receiving SACT with curative intent, who died from appropriately managed neutropenic sepsis.

A definitive decision regarding SACT's role in death was made in 60%: in 49% SACT was deemed non-contributory and in 11% SACT was deemed the cause of death. In 40% SACT did not play a major role, but a definitive negative association could not be made.

Conclusion: Development of a robust review process of 30-day mortality after SACT established a benchmark for SACT delivery for future comparisons and identified areas for SACT service organisation improvement. Moreover it encourages individual practice reflection and highlights the importance of balancing patients' needs and concerns with realistic outcomes and risks, particularly in heavily pre-treated patients or those of poor performance status.

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This is the beginning of an exploration of before as the thesis ‘before’ (temporally) and ‘be-fore’ (spatially) difference. Before denotes the origin and the desired destination. Before (in the double sense of ‘before’ and ‚be-in-the-fore’) opens up a space of pre-difference, of origin and of forgotten memory, as well as a space of desire, objective, illusion of teleology, unity, completion. Applied to the two domains of Human Rights and Sex/Gender, the space of ‘before’ yields two slightly different vistas: in human rights, a premodern, functionally undifferentiated society which had to invent human rights as its safeguards of functional differentiation. In Sex/Gender, 'before' brings a self-referential construction: that of ipseity, as the form of identity beyond comparison that does not play with id but with ipsum. Ipseity is inoperable but not useless. It is inoperable because it cannot be observed from anywhere without suffering rupture. It is not useless because it offers a ground for the reconceptualisation of difference, both through awe and desire.

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Field lab: Consumer insights

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Les virus exploitent la machinerie cellulaire de l'hôte pour se répliquer. Ils doivent s'adapter pour infecter la cellule hôte de manière optimale tout en échappant à la vigilance du système de défense de l'hôte. Ainsi l'hôte et les virus se livrent à de constantes batailles évolutives. Mon travail de thèse a porté sur l'étude des signatures évolutives de facteurs de l'hôte agissant comme des 'facteurs de restriction' en bloquant la réplication rétrovirale chez les primates. Plus spécifiquement, mon travail a visé à utiliser des données évolutives pour renseigner les analyses fonctionnelles et la biologie. Nous avons étudié le facteur anti-VIH-1 nommé TRIM5a (i) chez les prosimiens pour mieux comprendre son rôle dans le contrôle d'un lentivirus endogène, (ii) dans son activité contre d'autres anciennes infections représentées par des rétrovirus endogènes humains et (iii) en tant que protéine capable de générer des mutants de la capside. Premièrement nous nous sommes intéressés à TRIM5a chez deux espèces de lémuriens dont Microcebus murinus qui porte le lentivirus endogène PSIV dans son génome depuis plusieurs millions d'années,. Nous avons observé que TRIM5a chez M. murinus a un spectre d'activité antivirale réduit à l'opposé de TRIM5a chez le Lemur catta - non porteur du PSIV endogène - qui bloque une large variété de rétrovirus dont le PSIV. De ce fait TRIM5a aurait pu contribuer à protéger certaines espèces de lémuriens vis-à-vis d'anciennes infections par le PSIV. A l'inverse du PSIV, des virus dérivés des rétrovirus endogènes humains HERV-K and HERV-H se sont révélés largement résistants à l'inhibition par TRIM5a. Ces données illustrent une absence de protection par TRIM5a face à d'autres anciennes infections rétrovirales. Puis, pour évaluer l'impact de la protéine TRIM5a humaine sur le VIH-1, nous avons testé l'effet de mutations des résidues sous sélection positive dans la capside du VIH-1 sur l'inhibition par TRIM5a. Nos résultats montrent que TRIM5a ne jouerait pas un rôle significatif dans l'évolution de la capside du VIH-1. Enfin notre travail a porté sur le facteur anti-VIH-1 SAMHD1 récemment découvert, que nous avons séquencé chez 25 espèces de primates. L'analyse évolutive des sites sous sélection positive et des expériences fonctionnelles ont permis d'identifier le domaine de SAMHD1 interagissant avec la protéine lentivirale Vpx. De même que d'autres protéines virales contrecarrent les facteurs de restriction en les menant à la dégradation, nous avons observé que Vpx induit la dégradation de SAMHD1 de manière spécifique à l'espèce. Ces découvertes contribuent à comprendre comment les facteurs de restriction et les virus co-évoluent pour se neutraliser l'un l'autre. - Viruses hijack the host cellular machinery to replicate. They adapt to infect optimally host cells while escaping host defense systems. Viruses and the host coevolve in an evolutionary struggle. My thesis work has been devoted to study the evolutionary signatures of host factors acting as restriction factors that block retroviral replication in primates. Specifically, my work aimed at using evolutionary data to inform functional analyses and biology. We studied the anti-HIV-1 factor TRIM5a (i) in prosimians to better understand its possible role in the control of an endogenous lentivirus, (ii) in its activity against other ancient infections - as represented by HERVs, and (iii) as a protein capable of generating escape mutants in the viral capsid. First, my work focused on two lemur species, one of which was the gray mouse lemur that carries the endogenous lentivirus PSIV integrated in its genome for several million years. TRIM5a from gray mouse lemur exhibited a limited antiviral spectrum as opposed to TRIM5a from ring-tailed lemur - not a host of PSIV - that is able to block diverse retroviruses notably PSIV. These results support the possible contribution of TRIM5a in protecting lemur species from ancient infection by PSIV. In contrast, chimeric viruses derived from two human endogenous retroviruses were broadly resistant to TRIM5a-mediated restriction, suggesting TRIM5a lack of activity against other types of ancient infections. To evaluate the recent impact of human TRIM5a on HIV-1 evolution, we tested whether variants at positively selected sites in the HIV-1 capsid affected the ability of human TRIM5a alleles to restrict HIV-1. Our results indicate that TRIM5a does not play a significant role in the evolution of HIV1 capsid. At last, our work concentrated on the newly discovered anti-HIV-1 restriction factor SAMHD1. We determined its coding sequence in a panel of 25 species of primates. Evolutionary analyses of positively selected sites in SAMHD1 domains and functional assays identified the domain of SAMHD1 interacting with the lentiviral protein Vpx. Similar to other viral countermeasures targeting cellular restriction factors, Vpx was responsible of the degradation of SAMHD1 orthologs in a species-specific manner. These findings contributed to understanding how restriction factors and viruses evolve to counteract each other.

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Life on earth is subject to the repeated change between day and night periods. All organisms that undergo these alterations have to anticipate consequently the adaptation of their physiology and possess an endogenous periodicity of about 24 hours called circadian rhythm from the Latin circa (about) and diem (day). At the molecular level, virtually all cells of an organism possess a molecular clock which drives rhythmic gene expression and output functions. Besides altered rhythmicity in constant conditions, impaired clock function causes pathophysiological conditions such as diabetes or hypertension. These data unveil a part of the mechanisms underlying the well-described epidemiology of shift work and highlight the function of clock-driven regulatory mechanisms. The post-translational modification of proteins by the ubiquitin polypeptide is a central mechanism to regulate their stability and activity and is capital for clock function. Similarly to the majority of biological processes, it is reversible. Deubiquitylation is carried out by a wide variety of about ninety deubiquitylating enzymes and their function remains poorly understood, especially in vivo. This class of proteolytic enzymes is parted into five families including the Ubiquitin-Specific Proteases (USP), which is the most important with about sixty members. Among them, the Ubiquitin-Specific Protease 2 (Usp2) gene encodes two protein isoforms, USP2-45 and USP2-69. The first is ubiquitously expressed under the control of the circadian clock and displays all features of core clock genes or its closest outputs effectors. Additionally, Usp2-45 was also found to be induced by the mineralocorticoid hormone aldosterone and thought to participate in Na+ reabsorption and blood pressure regulation by Epithelial Na+ Channel ENaC in the kidneys. During my thesis, I aimed to characterize the role of Usp2 in vivo with respect to these two areas, by taking advantage of a total constitutive knockout mouse model. In the first project I aimed to validate the role of USP2-45 in Na+ homeostasis and blood pressure regulation by the kidneys. I found no significant alterations of diurnal Na+ homeostasis and blood pressure in these mice, indicating that Usp2 does not play a substantial role in this process. In urine analyses, we found that our Usp2-KO mice are actually hypercalciuric. In a second project, I aimed to understand the causes of this phenotype. I found that the observed hypercalciuria results essentially from intestinal hyperabsorption. These data reveal a new role for Usp2 as an output effector of the circadian clock in dietary Ca2+ metabolism in the intestine.

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National governments, the United Nations, and other organizations have deemed sport and other means of physical activity such as recreation, games and play for development a useful means for addressing a wide range of problems in communities and more specifically, providing youth with an opportunity to experience the benefits of physical activity. There is a need for research that furthers our understanding of how participants experience these programs. Specifically, the purpose of this study, was to better understand the lived experiences of the participants in a YMCA camp program that integrated physical activity and play for the specific development of poor youth street workers. A phenomenological approach infonned by a critical perspective (Creswell, 2003; Rossman & Rallis, 2003) was used. The study took place through the Asociaci6n Cristiana de J6venes de Costa Rica (ACJ) in Central America. The focus was on a camp program and the lived experiences of six purposefully chosen, youth street workers between the ages of 13-17. Their experiences were explored through semi-structured interviews. Other data that fonn the study include: field notes, observations, a reflexive journal and document analysis. The findings that emerged from the data include main themes of relationships, poverty, personal change and empowennent. For many youth, the ACJ is a relatively safe place to play, to "detach," their minds, to "distract" and "disorient" themselves from their dysfunctional families, violent neighbourhood, the poverty they live in, and from the necessity of having to work in the street to supplement the family income. Although many studies have shown that programs that include physical activity, play and/or sport have a positive impact on youth with regard to healthy development and improvements in well-being, there has been little work done to address the voices and experiences of the youth that participate in these programs. Using an interpretive-critical approach, this study focused on the participants' personal backgrounds, their experiences within the program and their critical reflections on the program. This study draws from a phenomenological philosophy and method to report findings from participants in an ACJ program in Costa Rica. This research shows how these youth were given the opportunity to use the program and the ACJ property as a relatively safe place to play, to behave like the youth they are, to establish and maintain their friendship networks, and develop empathy and conflict resolution skills. The fmdings from this study reveal how by participating in the ACJ program they each described a personal change, wherein they felt empowered to learn they could positivel y control themselves and as a result positively affect their own futures. These fmdings contribute knowledge surrounding the lived experiences of youth in developmental programs that use physical activity.

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Among the environmental factors that can affect food intake is the extent of dietary variety available in the environment. Numerous studies have demonstrated that variety in a meal can increase the amount of food consumed in humans, rats, and other species. A physiological mechanism that has been demonstrated to affect food intake is the gut peptide cholecystokinin (CCK) which is released from the upper small intestine during the ingestion of food. Peripherally administered CCK has a robust inhibitory effect on the intake of a single-food meal. Thus, dietary variety and CCK both affect meal size, with dietary variety increasing intake and CCK decreasing intake. This raises the question ofhow dietary variety and CCK might interact to affect meal size. Previous studies of CCK's effects have focused on situations in which only one food was available for consumption. However, in an animal's natural environment it would frequently occur that the animal would come across a number of foods either simultaneously or in quick succession, thus providing the animal access to a variety of foods during a meal. Accordingly, the effect ofCCK on food intake in single-food and multiple-food meals was examined. It was found that food intake was greater in multiple-food than in single-food meals provided that foods in the multiplefood meal were presented either simultaneously or in increasing order of preference. When foods in the multiple-food meal were presented in decreasing order of preference, intake was similar to that observed in single-food meals. In addition, it was found that CCK inhibited food intake in a dose-dependent manner, and that its effects on food intake were similar regardless of meal type. Therefore, the inhibitory effects ofCCK were not diminished when a variety of foods were available for consumption. Furthermore, the finding that CCK did not differentially affect the intake of the two types of meals does not provide support for the recent-foods hypothesis which postulates that CCK decreases food intake by reducing the palatability of only recently consumed foods. However, it is consistent with the all-foods hypothesis, which predicts that CCK reduces food intake by decreasing the palatability of all foods. The 600 ng/kg dose of the CCK^-antagonist lorglumide significantly antagonized the inhibitory effect of exogenous CCK on food intake, and the magnitude of this effect was similar for both types of meal. These results suggest that exogenous CCK inhibits food intake through the activation ofCCK^ receptors. However, when administered by itself, the 600^ig/kg dose of lorglumide did not increase food intake in either single-food or multiple-food meals, suggesting that peripheral endogenous CCK may not play a major role in the control of food intake.