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1.
Bull Cancer ; 111(2): 199-212, 2024 Feb.
Article in French | MEDLINE | ID: mdl-38123413

ABSTRACT

Systematic screening for pancreatic cancer in high risk individuals is justified by the poor prognosis of the majority of cases diagnosed at a symptomatic stage that are mostly advanced and unresectable Individual risk assessment is based on both genetic data and family history. The screening of a panel of susceptibiility genes should be offered to any affected individual when a genetic predisposition is suspected. An international consortium has proposed a definition of the at risk population, candidate for screening, and there is a consensus on the target lesions of this screening: early adenocarcinoma and benign lesions with a high potential for malignant transformation: Intraductal Papillary Mucinous Neopasm (IPMN) and Pancreatic Intraepithelial Neoplasia (PanIN) with high-grade dysplasia. Its modalities currently consist of an annual pancreatic MRI and/or endoscopic ultrasound (EUS), associated with screening for diabetes mellitus. The main limitation of screening, the effectiveness of which has not yet been demonstrated, is its lack of sensitivity, which results in a non-negligible rate of interval cancers and sometimes advanced diagnoses. Insufficient specificity is also imperfect, in particular with regard to benign lesions with a low potential for degeneration, and can lead to the proposal of unjustified surgeries. This situation makes the future integration of new imaging techniques and promising new biological approaches that are being explored highly desirable.


Subject(s)
Adenocarcinoma , Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Humans , Pancreatic Neoplasms/diagnostic imaging , Pancreatic Neoplasms/genetics , Adenocarcinoma/diagnostic imaging , Adenocarcinoma/genetics , Genetic Determinism , Pancreas/diagnostic imaging , Pancreas/pathology , Endosonography , Carcinoma, Pancreatic Ductal/diagnostic imaging , Carcinoma, Pancreatic Ductal/genetics
2.
Can J Infect Dis Med Microbiol ; 2016: 7231805, 2016.
Article in English | MEDLINE | ID: mdl-27478446

ABSTRACT

An 88-year-old man was admitted to the hospital with worsening malaise, fever, and weakness. Anaerobic blood culture bottles revealed the presence of an anaerobic, Gram-positive sporulated bacillus. Empirical antibiotherapy with intravenous piperacillin-tazobactam was initiated. The patient defervesced after four days and was switched to oral amoxicillin on his 6th day of antibiotic therapy and later discharged from the hospital. Four months later, he had recovered. The bacterium was initially identified as Clostridium butyricum using anaerobic manual identification panel. 16S rRNA gene sequence and phylogenetic analysis showed the bacterium to be Clostridium lavalense, a recently described species with no previously published case of isolation in human diagnostic samples so far. This is the first report of Clostridium lavalense isolation from human blood cultures. Further studies are needed in order to elucidate the role of Clostridium lavalense in human disease and its virulence factors.

3.
Sleep Med ; 15(1): 71-5, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24239496

ABSTRACT

OBJECTIVE: The goal of our study was to examine the associations between sleep and eating behaviors. Specifically, we examined associations between sleep duration and continuity with behaviors that promote eating regardless of true physiologic hunger state including emotional (food intake in response to emotional distress) external (eating in response to the sight or smell of food), and restrained eating (a paradoxical behavior; food intake is initially reduced to lose or maintain body weight, but followed by increased consumption and binge eating). PARTICIPANTS: Fifty-six children (29 boys; 27 girls) ages 5 to 12 years participated in the study. Mean age was 7.7±1.9 years, and average body mass index (BMI) was within the healthy range (17.8±4.3 kg/m(2)). METHODS: Sleep duration, continuity and schedule were assessed using actigraphy and self-reports. The Child Dutch Eating Behavior Questionnaire-modified version (DEBQ-M) was used to examine levels of emotional, external and restrained eating in the children. RESULTS: Associations between the sleep and eating behaviors were examined using partial correlations and multiple regression analyses. External eating score was negatively associated with sleep duration; emotional eating score was associated with lower levels of sleep continuity; and restrained eating score were associated with a later sleep start and later bedtime. CONCLUSIONS: Short sleep duration and poor sleep continuity were associated with higher levels of eating behaviors shown to be associated with increased food intake. Therefore, sleep loss may be associated with diminished self-regulation of appetite in children, increasing the risk for overeating and obesity.


Subject(s)
Binge-Eating Disorder/physiopathology , Feeding Behavior/physiology , Obesity/physiopathology , Sleep Initiation and Maintenance Disorders/physiopathology , Sleep/physiology , Actigraphy , Affective Symptoms/physiopathology , Affective Symptoms/psychology , Binge-Eating Disorder/psychology , Body Weight/physiology , Child , Child Behavior/physiology , Child Behavior/psychology , Child, Preschool , Emotions/physiology , Female , Humans , Male , Obesity/psychology , Regression Analysis , Self Report , Sleep Initiation and Maintenance Disorders/psychology
4.
Emerg Infect Dis ; 19(1): 119-22, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23260201

ABSTRACT

We describe 3 culture-proven cases of adenovirus serotype 14 infection in New Brunswick, Canada, during the summer of 2011. Strains isolated from severely ill patients were closely related to strains of a genomic variant, adenovirus 14p1, circulating in the United States and Ireland. Physicians in Canada should be aware of this emerging adenovirus.


Subject(s)
Adenovirus Infections, Human/diagnosis , Adenovirus Infections, Human/virology , Adenoviruses, Human/genetics , RNA, Viral/genetics , Adenovirus Infections, Human/pathology , Adenoviruses, Human/classification , Adenoviruses, Human/isolation & purification , Aged , Fatal Outcome , Female , Humans , Infant , Male , Middle Aged , New Brunswick , Phylogeny , RNA, Viral/classification , RNA, Viral/isolation & purification , Serotyping
5.
Appetite ; 59(3): 790-5, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22841813

ABSTRACT

Food intake can be increased by learning to anticipate the omission of subsequent meals. We present here a new theory that such anticipatory eating depends on an associative process of instrumental reinforcement by the nutritional repletion that occurs when access to food is restored. Our evidence over the last decade from a smooth-brained omnivore has been that food after deprivation rewards intake even when those reinforced ingestive responses occur long before the physiological signals from renewed assimilation. Effects of food consumed after self-deprivation might therefore reward extra eating in human beings, through brain mechanisms that could operate outside awareness. That would have implications for efforts to reduce body weight. This food reward mechanism could be contributing to the failure of the dietary component of interventions on obesity within controlled trials of the management or prevention of disorders such as hypertension, atherosclerosis and type 2 diabetes.


Subject(s)
Anticipation, Psychological , Energy Intake , Feeding Behavior/psychology , Food Deprivation , Obesity/psychology , Reward , Satiety Response , Animals , Association , Awareness , Brain , Humans , Meals/psychology , Psychological Theory , Weight Loss
6.
Appetite ; 59(2): 224-7, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22595288

ABSTRACT

Rats can learn to anticipate the omission of subsequent meals by increasing food intake. Our previous reports have analysed group means at each trial but that does not allow for rats learning at different speeds. This paper presents instead a rat-by-rat analysis of all the raw data from previous experiments. The re-analysis supports the published evidence that the capacity for reinforcement generated by withholding of food is greater after a longer fast than after a shorter fast, but that the learning is quicker after the shorter fast. The individualised analyses also extend the evidence that the pattern of learning, extinction and re-learning with shorter fasts is similar to that with longer fasts. These findings indicate that, contrary to our previous interpretation, a single learning mechanism can explain the effects of both durations of food deprivation.


Subject(s)
Appetite Regulation/physiology , Extinction, Psychological/physiology , Feeding Behavior/physiology , Food Deprivation/physiology , Reinforcement, Psychology , Animals , Energy Intake , Meals , Rats
7.
Article in English | MEDLINE | ID: mdl-23450274

ABSTRACT

INTRODUCTION: Little is known about the role of herpes simplex virus (HSV) type 1 (HSV1) in the epidemiology of genital herpes in Canada. Data on herpes viral cultures for two consecutive years obtained from L'Hôpital Dr GL Dumont, which performs all the viral culture testing in New Brunswick, were reviewed. It was hypothesized that HSV1 was the main cause of genital herpes in New Brunswick. METHODS: Samples of genital origin sent to the laboratory for HSV culture testing between July 2006 and June 2008 were analyzed. Samples from an unspecified or a nongenital source were excluded from analysis. Multiple positive samples collected from the same patient were pooled into a single sample. RESULTS: HSV was isolated from 764 different patients. HSV1 was isolated in 62.6% of patients (male, 55%; female, 63.8%). HSV1 was isolated in 73.2% of patients 10 to 39 years of age and in 32% of patients ≥40 years of age. The difference in rates of HSV1 infection between the 10 to 39 years of age group and the ≥40 years of age group was statistically significant (P<0.001 [χ(2)]). In a similar Canadian study performed in Nova Scotia, HSV1 was recovered in 53.7% of positive cultures (male, 36.7%; female, 58.1%). The rates of HSV1 infection reported by this study and the present study were significantly different (P<0.001 [χ(2)] for male, P=0.012 for female). CONCLUSION: In New Brunswick, HSV1 is the dominant type of HSV isolated in samples collected from a genital site. Significant rate differences were demonstrated between the groups 10 to 39 years of age and ≥40 years of age. INTRODUCTION: Little is known about the role of herpes simplex virus (HSV) type 1 (HSV1) in the epidemiology of genital herpes in Canada. Data on herpes viral cultures for two consecutive years obtained from L'Hôpital Dr GL Dumont, which performs all the viral culture testing in New Brunswick, were reviewed. It was hypothesized that HSV1 was the main cause of genital herpes in New Brunswick. METHODS: Samples of genital origin sent to the laboratory for HSV culture testing between July 2006 and June 2008 were analyzed. Samples from an unspecified or a nongenital source were excluded from analysis. Multiple positive samples collected from the same patient were pooled into a single sample. RESULTS: HSV was isolated from 764 different patients. HSV1 was isolated in 62.6% of patients (male, 55%; female, 63.8%). HSV1 was isolated in 73.2% of patients 10 to 39 years of age and in 32% of patients ≥40 years of age. The difference in rates of HSV1 infection between the 10 to 39 years of age group and the ≥40 years of age group was statistically significant (P<0.001 [χ2]). In a similar Canadian study performed in Nova Scotia, HSV1 was recovered in 53.7% of positive cultures (male, 36.7%; female, 58.1%). The rates of HSV1 infection reported by this study and the present study were significantly different (P<0.001 [χ2] for male, P=0.012 for female). CONCLUSION: In New Brunswick, HSV1 is the dominant type of HSV isolated in samples collected from a genital site. Significant rate differences were demonstrated between the groups 10 to 39 years of age and ≥40 years of age.


INTRODUCTION: On ne sait pas grand-chose du rôle du virus de l'herpès simplex de type 1 (VHS1) dans l'épidémiologie de l'herpès génital au Canada. Les chercheurs ont analysé les données des cultures d'herpès viral obtenues pendant deux années consécutives à L'Hôpital Dr-Georges-L.-Dumont, où toutes les cultures virales sont effectuées au Nouveau-Brunswick. Ils ont postulé que le VHS1 était la principale cause d'herpès génital dans la province. MÉTHODOLOGIE: Les chercheurs ont analysé les prélèvements génitaux envoyés en laboratoire entre juillet 2006 et juin 2008, en vue de cultures du virus d'herpès simplex (VHS). Ils ont exclu de l'analyse les prélèvements tirés d'une source non précisée ou d'origine non génitale. Ils ont regroupé dans un seul échantillon les multiples échantillons positifs prélevés chez le même patient. RÉSULTATS: Le VHS a été isolé chez 764 patients, et le VHS1, chez 62,6 % des patients (55 % chez les hommes, et 63,8 % chez les femmes), soit 73,2 % des patients de dix à 39 ans et 32 % des patients de 40 ans et plus. La différence de taux d'infection par le VHS1 entre le groupe des dix à 39 ans et celui des 40 ans et plus était statistiquement significative (χ2, P<0,001). Dans une étude canadienne similaire menée en Nouvelle-Écosse, 53,7 % des cultures positives contenaient le VHS1 (36,7 % chez les hommes, 58,1 % chez les femmes). Le taux d'infection par le VHS1 déclaré dans cette étude et celui de la présente étude différaient de manière significative (χ2, P<0,001 chez les hommes, P=0,012 chez les femmes). CONCLUSION: Au Nouveau-Brunswick, le VHS1 est le principal type de VHS isolé dans des échantillons d'origine génitale. On a établi des différences de taux significatives entre le groupe des dix à 39 ans et celui des 40 ans et plus.

8.
Chronobiol Int ; 28(3): 216-28, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21452917

ABSTRACT

The eating pattern is altered by high-fat diet-induced obesity. To clarify whether this is dependent on the fatty acid profile of the diet, the authors conducted two studies on adult female Sprague-Dawley rats fed normal-fat chow or high-fat diets with varying fatty acid composition. Eating pattern and body weight were assessed in rats fed canola-based (low in saturated fatty acids) or lard-based (moderate in saturated fatty acids) diets for 7 days, and in animals fed chow or canola- or butter-based diets (rich in saturated fatty acids) for 43 days. These parameters were also determined when restricted amounts of low-fat canola- or butter-based diets were consumed for 25 days. Early exposure to canola or lard high-fat feeding or prolonged access to canola- or butter-based fat-rich diets (relative to chow feeding) did not alter the normal light-dark distribution of food and energy intake. All animals ingested most of their food during the dark phase. However, feeding the high-fat canola- and butter-based diets produced an altered eating pattern during the light phase characterized by a smaller number of meals, longer intermeal interval, and enhanced satiety ratio, and consumption of shorter-lasting meals than chow-fed animals. Relative to canola or chow feeding, butter-fed animals consumed a lower number of meals during the dark phase and had a higher eating rate in the light phase, but ate larger meals overall. Only butter feeding led to overeating and obesity. When given a restricted amount of low-fat canola- or butter-based diet at the start of the light phase, rats ate most of their food in that phase and diurnal rather than nocturnal feeding occurred with restriction. These findings underscore the role of saturated fatty acids and the resulting eating pattern alteration in the development of obesity.


Subject(s)
Animal Feed/analysis , Circadian Rhythm/physiology , Eating/physiology , Feeding Behavior/physiology , Obesity/metabolism , Animals , Butter , Diet , Dietary Fats , Fatty Acids, Monounsaturated , Female , Rapeseed Oil , Rats , Rats, Sprague-Dawley
9.
Article in English | MEDLINE | ID: mdl-22379488

ABSTRACT

Adenovirus is a commonly isolated virus in clinical samples. Life-threatening infections, although rare, are described worldwide. An epidemic spread of an adenovirus type 3 strain occurred in the province of New Brunswick during the fall of 2008 to the winter of 2009; it resulted in three severely ill patients, with one fatality. Adenovirus should be considered as a cause of severe community-acquired viral pneumonia, especially when the influenza test is negative.

10.
Nutr Res Rev ; 23(2): 270-99, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20977819

ABSTRACT

Epidemiological studies have shown a positive relationship between dietary fat intake and obesity. Since rats and mice show a similar relationship, they are considered an appropriate model for studying dietary obesity. The present paper describes the history of using high-fat diets to induce obesity in animals, aims to clarify the consequences of changing the amount and type of dietary fats on weight gain, body composition and adipose tissue cellularity, and explores the contribution of genetics and sex, as well as the biochemical basis and the roles of hormones such as leptin, insulin and ghrelin in animal models of dietary obesity. The major factors that contribute to dietary obesity - hyperphagia, energy density and post-ingestive effects of the dietary fat - are discussed. Other factors that affect dietary obesity including feeding rhythmicity, social factors and stress are highlighted. Finally, we comment on the reversibility of high-fat diet-induced obesity.


Subject(s)
Dietary Fats/adverse effects , Obesity/etiology , Adipose Tissue/cytology , Adipose Tissue/drug effects , Animals , Body Composition/drug effects , Disease Models, Animal , Energy Intake , Feeding Behavior , Ghrelin/physiology , Humans , Hyperphagia , Insulin/physiology , Leptin/physiology , Obesity/genetics , Obesity/therapy , Sex Factors , Social Environment , Stress, Psychological , Weight Gain/drug effects
11.
Nutr Res ; 30(9): 632-43, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20934605

ABSTRACT

The present study tested the hypothesis that a saturated fatty acid (SFA)-rich diet is more obesogenic than diets with lower SFA content. In 8 female Sprague-Dawley rats fed a low-SFA canola or a moderate-SFA lard-rich diets at 67% of energy for 26 days, body weight gain, final body weight, obesity index, and food and energy intake were comparable. Twenty-nine rats were fed canola or high-SFA butter-rich diets (67% of energy) or chow for 50 days; then high-fat feeding was followed by ad libitum low-fat feeding (27% of energy) for 28 days and by a food-restricted low-fat diet for 32 days. High-fat feeding resulted in a greater body weight gain (P < .04), final body weight (P < .04), and energy intake (P < .008) in butter-fed rats than in canola- and chow-fed controls, after 26 or 50 days. Ad libitum canola and butter low-fat diets or chow feeding resulted in similar weight change, whereas food-restricted low-fat diets led to comparable weight loss and final weight. Canola-fed animals adjusted their intake based on diet energy density, whereas lard and butter-fed animals failed to do so. Abdominal fat (P = .012) and plasma leptin (P = .005) were higher in chow-fed controls than in canola-fed rats, but comparable with those of butter-fed rats. Prone and resistant phenotypes were detected with high-fat feeding. In conclusion, only feeding the high-SFA butter-rich diet led to obesity development and failure to adjust intake based on the energy density and preserving body fat even after weight loss. The high availability of SFA-rich foods in today's obesogenic environment could contribute to develop and maintain obesity.


Subject(s)
Abdominal Fat/drug effects , Appetite Regulation/drug effects , Dietary Fats/adverse effects , Energy Intake/drug effects , Fatty Acids/adverse effects , Obesity/etiology , Weight Gain/drug effects , Animals , Body Weight/drug effects , Butter/adverse effects , Diet, Fat-Restricted , Diet, Reducing , Dietary Fats/administration & dosage , Fatty Acids/administration & dosage , Fatty Acids, Monounsaturated/pharmacology , Female , Food Deprivation , Leptin/blood , Obesity/blood , Obesity/physiopathology , Rapeseed Oil , Rats , Rats, Sprague-Dawley , Weight Loss/drug effects
12.
Ann Nutr Metab ; 54(1): 75-82, 2009.
Article in English | MEDLINE | ID: mdl-19270448

ABSTRACT

BACKGROUND/AIMS: Isomaltulose (alpha-D-glucosylpyranosyl-1,6-D-fructofuranose) is a natural disaccharide used in human nutrition. It is structurally related to sucrose, but more slowly hydrolyzed and absorbed. Because this sugar's metabolic effects are poorly characterized, we compared the effects of chronic ad libitum access to high-isomaltulose and high-sucrose diets on glucose metabolism in rats. METHODS: Adult male rats were offered 62% isomaltulose, sucrose or starch diets ad libitum for 26 (trial 1) or 56 (trial 2) days. After 2- to 3-week adaptation, plasma glucose, fructose and insulin were measured after test meals of the adaptation diet. RESULTS: The main finding was that both plasma glucose and plasma insulin concentrations were transiently but markedly increased after sucrose test meals compared to isomaltulose or starch meals. These differences were not associated with consistent differences in food intake, body weight gain or adiposity. CONCLUSIONS: Chronic isomaltulose feeding has beneficial effects on postprandial glucose metabolism in comparison to sucrose feeding in rats, although the effects are modest. Further work is warranted to determine whether substitution of isomaltulose for sucrose or other sweet carbohydrates might be therapeutically useful in patients with, or at risk for, insulin resistance or type 2 diabetes mellitus.


Subject(s)
Blood Glucose/drug effects , Blood Glucose/metabolism , Dietary Sucrose/administration & dosage , Insulin/blood , Isomaltose/analogs & derivatives , Animals , Area Under Curve , Diabetes Mellitus, Type 2/diet therapy , Dietary Sucrose/metabolism , Disease Models, Animal , Energy Intake/drug effects , Energy Intake/physiology , Isomaltose/administration & dosage , Isomaltose/metabolism , Male , Postprandial Period , Random Allocation , Rats , Rats, Sprague-Dawley , Weight Gain/drug effects , Weight Gain/physiology
13.
Q J Exp Psychol (Hove) ; 62(4): 663-72, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19048448

ABSTRACT

Several recent experiments have provided evidence that the ingestion of a distinctive food by rats can be a learnt instrumental act as well as an associatively conditioned reaction. In the previous work, maintenance food was withheld for shorter and longer durations on different days following access to the training food. Extra eating before the longer fast was interpreted as avoidance of hunger. This interpretation was based on the evidence showing that extra eating as a result of classical conditioning comes from pairing food stimuli with the presence of little or no hunger because of repletion with energy nutrients. The theory that the extra eating arose from a response-depletion contingency was tested in the present experiment by training rats on only a long fast or only a short fast. Greater increase in intake was seen before the longer fast. The results also replicated previously seen cycles of increase, decrease, and renewed increase in putative deficit-avoidant eating over about three trials, indicating that the extra eating reduces the response-reinforcing hunger and that the consequent part-extinction restores reinforcement. The shape of the learning curve was consistent with these cycles occurring from the start of training, further supporting the view that the increase in food intake before a long delay in refeeding is hunger-reinforced instrumental behaviour.


Subject(s)
Avoidance Learning , Feeding Behavior , Hunger , Animals , Learning , Male , Rats , Rats, Sprague-Dawley , Time Factors
15.
Physiol Behav ; 92(4): 541-7, 2007 Nov 23.
Article in English | MEDLINE | ID: mdl-17540415

ABSTRACT

Anticipatory hunger is a learnt increase in intake of food having a flavour or texture that predicts a long fast. This learning was studied in rats trained on a single food or a choice between protein-rich and carbohydrate-rich foods, presented for 1.5 h after 3 h without maintenance food at the start of the dark phase. Eight training cycles provided a pseudo-random sequence of 3 h and 10 h post-prandial fasts with a day on maintenance food between each training fast. The measure of anticipatory hunger is the difference over one 4-day cycle between the intake of test food having an odour predictive of the longer fast (TL) and intake of food with an odour cuing to the shorter fast (TS). Previous experiments showed that conditioning of preference for the odour before the shorter fast competes with learning to avoid hunger during the longer fast (anticipatory hunger), generating a cubic or quartic contrast. TL minus TS showed a strong cubic trend over 8 training cycles with both single and choice meals. There was a switch from preference for the short-fast odour at cycle 2 (TL-TS=-0.86 g) to a peak of anticipatory hunger at cycle 6 (TL-TS=1.57 g). We conclude that anticipatory hunger is learnt when a choice is given between protein-rich and carbohydrate-rich foods as well as on a single food. In addition, since anticipatory hunger extinguishes itself, such learning improves on negative-feedback homeostasis with a feed-forward "hyper-homeostatic" mechanism.


Subject(s)
Appetite Regulation/physiology , Association Learning/physiology , Food Preferences/physiology , Hunger/physiology , Postprandial Period/physiology , Adaptation, Physiological , Animals , Appetitive Behavior/physiology , Choice Behavior , Discrimination, Psychological/physiology , Eating/physiology , Eating/psychology , Female , Food Preferences/psychology , Generalization, Psychological , Odorants , Rats , Rats, Sprague-Dawley , Satiation/physiology , Statistics, Nonparametric , Taste/physiology , Time Factors
16.
Physiol Behav ; 88(1-2): 201-10, 2006 Jun 15.
Article in English | MEDLINE | ID: mdl-16682060

ABSTRACT

Recent evidence indicates that rats can learn to avoid aversive consequences of several hours of food deprivation by eating more of food having orosensory characteristics that predict a protracted fast. Two new studies tested if macronutrient composition of a flavoured meal before the reinforcing fast influences this acquisition of anticipatory hunger/satiety in a smooth-brained mammal. In one study, female Sprague-Dawley rats were trained for 11 cycles of 4 days with experimental meals of either carbohydrate or protein flavoured with either grape or cherry, with one odour followed by a 3-h fast and the other by 10 h of food deprivation. Both nutrient groups acquired anticipatory hunger. Then that learnt increase in meal size started to extinguish the hunger-avoidance response to the longer fast. The other study tested if this finding extended to experimental meals that combined carbohydrate and protein, and had vanilla or chicken flavours, to fasts of 4 and 12 h and to male rats as well as females within a training period of 6 cycles of 4 days. Evidence of anticipatory hunger early in training was clear only in the males. The combined results from the two experiments indicate that either carbohydrate or protein is sufficient for negative reinforcement of flavour-specific anticipatory hunger when the shorter fast lasts for 3 h. This food-discriminative anticipatory adjustment of meal size could be an automatically learnt part of hunger management for socially scheduled eating in human beings.


Subject(s)
Carbohydrates/administration & dosage , Feeding Behavior/physiology , Flavoring Agents/administration & dosage , Hunger/physiology , Proteins/administration & dosage , Reinforcement, Psychology , Analysis of Variance , Animals , Behavior, Animal , Eating , Female , Male , Rats , Rats, Sprague-Dawley , Sex Factors
17.
Br J Nutr ; 92 Suppl 1: S41-5, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15384322

ABSTRACT

The prevalence of obesity among adults and children has increased steadily over the last few years worldwide, reaching epidemic proportions. Particularly alarming is the link between obesity and the development of chronic disorders such as heart disease, type 2 diabetes, hypertension and some cancers (Bjorntorp, 1997). Environmental causes of obesity are thought to include a sedentary lifestyle and an abundance of highly palatable energy-dense foods (Hill et al. 2003). Genetic factors also contribute to susceptibility to obesity, although the genetic basis of most human obesities is thought to be polygenic (Comuzzie & Allison, 1998; Barsh et al. 2000). The present paper considers some of the animal models used to infer aspects of human obesity, with an emphasis upon their usefulness.


Subject(s)
Homeostasis/physiology , Models, Animal , Obesity/physiopathology , Animals , Eating/physiology , Energy Metabolism/physiology , Ethics, Medical , Food Preferences/physiology , Humans , Obesity/genetics
18.
Chronobiol Int ; 21(3): 385-92, 2004 May.
Article in English | MEDLINE | ID: mdl-15332444

ABSTRACT

Rats with ad libitum water and the ability to self-select among three macronutrient-rich diets--carbohydrate (CHO), protein (PRO), and lipid (LIP)--show a circadian rhythmicity in their ingestion. The aim of the present study was to determine whether this circadian rhythmicity is reliable from day to day. Eight rats were offered ad libitum water and a choice of three isoenergetic diet rations providing carbohydrate, protein, and lipid. Water and food intake was recorded every 3 h for 7 days. The reliability of the circadian rhythm of water and food intake was assessed by the Intraclass Correlation Coefficient (ICC) and the test-retest reliability using the Pearson's Correlation Coefficient (r). The results showed that the circadian rhythm of water, CHO, and PRO intake are strongly reliable. However, the circadian rhythm of LIP intake is less reproducible. Among the three reliable parameters-water, CHO, and PRO, the circadian rhythm of water intake was the most reproducible over 7 days. This suggests that water intake may be used as a marker of circadian rhythmicity in ingestive behavior.


Subject(s)
Circadian Rhythm/physiology , Drinking/physiology , Eating/physiology , Animals , Dietary Carbohydrates/administration & dosage , Dietary Fats/administration & dosage , Dietary Proteins/administration & dosage , Male , Rats , Rats, Sprague-Dawley , Reproducibility of Results
19.
J Cell Sci ; 117(Pt 2): 327-37, 2004 Jan 15.
Article in English | MEDLINE | ID: mdl-14676281

ABSTRACT

Studies employing human fetal intestine have yielded remarkable information on the role of polarized enterocytes in fat absorption. In this report, we investigated the intestinal expression, spatiotemporal distributions, ontogeny and function of the scavenger receptor, Class B, Type I (SR-BI) that plays a crucial role in cholesterol homeostasis. SR-BI was detected as early as week 14 of gestation in all gut segments and was almost entirely confined to the absorptive epithelial cells. By using immunofluorescence staining, the distribution of SR-BI rarely appeared as a gradient, increasing from the developing crypt to the tip of the villus. Western blot showed high levels of immunodetectable SR-BI in the duodenum, which progressively decreased toward the distal colon. The high-resolution immunogold technique revealed labelling mainly over microvilli of the enterocyte. SR-BI was not associated with caveolin-1 and was not detectable in caveolae. In order to define the role of SR-BI in intestinal cholesterol absorption, Caco-2 cells were transfected with a constitutive expression vector (pZeoSV) containing human SR-BI cDNA inserted in an antisense orientation. As noted by immunoblotting and Protein A-gold techniques, stable transformants contained 40, 60 and 80% the SR-BI level of control Caco-2 cells and exhibited a proportional drop in free cholesterol uptake without altering the capture of phospholipids or cholesteryl ester. Confirmation of these data was obtained in intestinal organ culture where SR-BI antibodies lowered cholesterol uptake. These observations suggest that the human intestine possesses a developmental and regional SR-BI pattern of distribution, and extends our knowledge in SR-BI-mediated cholesterol transport.


Subject(s)
Caveolins/metabolism , Cholesterol/metabolism , Enterocytes/metabolism , Intestinal Mucosa/metabolism , Animals , Caveolin 1 , Cells, Cultured , Enterocytes/ultrastructure , Humans , Intestinal Absorption , Intestines/cytology , Microscopy, Fluorescence , Microscopy, Immunoelectron
20.
J Ren Nutr ; 13(2): 84-92, 2003 Apr.
Article in English | MEDLINE | ID: mdl-12671830

ABSTRACT

OBJECTIVE: The objective of the present study was to look at the effect of a protein-rich diet on cyclosporine A (CsA)-induced acute nephrotoxicity in rodents using markers of tubular damage. DESIGN: Female Sprague-Dawley rats were conditioned to either a standard or a casein-rich diet for 2 weeks. Then, they were given CsA intraperitoneally (25 mg/kg/24 h or an equivalent volume of vehicle (Cremophor EL; Sigma Chemical Co, St. Louis, MO) for 7 days at 7 AM. RESULTS: During CsA treatment, bodyweight, caloric consumption, water intake, and urine output were not significantly different in animals fed with the standard Rat Chow and those on the high-protein feeding. On days 1 and 7, the 24-hour urine excretion of N-acetyl-beta-d-glucosaminidase (NAG) and beta-galactosidase (beta-GAL) were significantly (P < .001) lower in CsA-treated rats on the high-protein diet than in those on the standard Rat Chow. After 7 days of treatment with CsA, no significant difference in the renal function level was found between rats fed with the standard or the casein-rich diet. The post-necrotic cellular regeneration in renal cortex was significantly lower (p<0.001) in CsA-treated rats on the high-protein than on the standard diet. In CsA-treated rats on the standard diet, immunogold labeling showed a massive and specific concentration of the drug into lysosomes of proximal tubular cells. Contrastingly, no gold particle was found over the lysosomes of animals given the rich-protein feeding. CONCLUSION: In our current experimental conditions, a protective effect of high-casein diet against CsA-induced proximal tubular damage was observed in Sprague-Dawley rats.


Subject(s)
Cyclosporine/adverse effects , Dietary Proteins/administration & dosage , Kidney Diseases/prevention & control , Acetylglucosaminidase/urine , Animals , Body Weight , Caseins/administration & dosage , Creatinine/blood , Cyclosporine/analysis , Diet, Fat-Restricted , Diuresis , Drinking , Energy Intake , Female , Immunohistochemistry , Kidney Diseases/chemically induced , Kidney Tubules, Proximal/chemistry , Kidney Tubules, Proximal/ultrastructure , Rats , Rats, Sprague-Dawley , beta-Galactosidase/urine , gamma-Glutamyltransferase/urine
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