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Au Québec, le législateur a décidé de confier la résolution des litiges naissant des baux résidentiels à un tribunal administratif, la Régie du logement, plutôt qu’aux tribunaux civils ordinaires. Par la Loi sur la Régie du logement, L.Q. 1979, c. 48, celle-ci se voit attribuer une compétence dévolue jusque-là à un autre tribunal administratif, la Commission des loyers, compétence qui s’exerçait principalement en matière de contrôle des loyers et d’exercice par le locataire de son droit au maintien dans les lieux loués. La Loi attribue également à la Régie le pouvoir de connaître toute demande relative au bail d’un logement qui était jusque-là de la compétence de la Cour provinciale : réclamation de loyer, résiliation de bail par exemple. En plus de ses attributions de type quasi judiciaire, la Régie se voit confier d’autres fonctions : information, conciliation, régulation. Ainsi, elle doit informer les locataires et les propriétaires sur leurs droits et obligations. Elle assume ce mandat de deux façons : par une information de masse faisant appel aux différents médias de communication : imprimé, radio, télévision, ..., et par une information personnalisée, par le biais d’une aide individuelle apportée à chaque personne qui en fait la demande. La Régie doit également tenter d’amener la solution des conflits par la voie de la conciliation. Ses efforts se sont jusqu’à maintenant concentrés surtout sur la conciliation en matière de détermination du loyer. Organisme de régulation, la Régie l’est par le rôle que l’État lui attribue en matière de contrôle des démolitions de logements, des transformations d’immeubles loués en copropriété et des aliénations d’immeubles situés dans des ensembles immobiliers où de tels gestes ne peuvent être posés que moyennant une autorisation préalable de la Régie. Celle-ci doit décider en fonction de l’opportunité compte tenu de l’intérêt public et de l’intérêt des parties. Pour rendre la Régie facilement accessible au justiciable, on y a prévu une procédure simplifiée et un coût réduit. Les règles de preuve qui s’appliquent sont celles du Code civil, avec un certain assouplissement, en particulier en matière d’admissibilité de la preuve testimoniale.

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.

The effects of neuropeptide Y (NPY) injected into the hypothalamic suprachiasmatic nucleus (SCN) or the lateral cerebral ventricle (LCV) at four different time points of the day on the subsequent 2h food intake from three macronutrient rich diets were examined. Adult Wistar male rats on 12-12 h light-dark cycles received either saline or NPY (lOOpmol) through chronically implanted guide cannulas into the SCN or the LCV. The results show that NPY was effective at stimulating energy intake from the dextrin/sucrose diet when injected in the SCN after lights-on, and total energy intake when injected in the LCV before and after lights-on. This suggests that NPY is effective at altering nychthemeral variations in total energy and energy from dextrin/sucrose diets, but this modulation is specific to the site of administration.

This study investigated eating pattern in weaning female Sprague-Dawley rats fed high-fat diets of varying fatty acid composition. Rats were randomly assigned to canola- or butter-based diets, and their eating pattern and body weight were assessed at early exposure (P1) and following 3 weeks (P2). In P2, a lower 24-h intake, smaller meal size, and shorter nocturnal meal duration were found in both dietary groups. In both groups, 24-h intakes were comparable throughout the experiment; however, butter-fed rats gained more weight. With canola feeding, P1 nocturnal intake was greater than diurnal intake, but intakes were comparable in P2. Butter-fed rats had similar diurnal and nocturnal intakes in P1; in P2, diurnal was greater than nocturnal intake. Canola-fed rats had similar diurnal and nocturnal meal size and eating rate, whereas butter-fed rats ate larger meals at a higher rate in the light than in the dark phase. The present work brings new knowledge about exposure to high-fat diets early in life and l...

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.

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.

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.

Aminoglycosides (AG) such as gentamicin are antimicrobial drugs widely used in the hospital setting due to their efficacy in the treatment of severe gram-negative bacterial infections. However, all AG have the potential to cause nephrotoxicity. Two studies have been conducted (1) to assess the protein level of a diet that would give the best renal outcome with gentamicin administration, and (2) to get a better idea about the rhythms of food ingestion associated with the different protein levels. Adult female Sprague-Dawley rats fully adapted to a standard chow diet, the standard chow with 20% or 55% added casein were chronically treated for 10 days with a nephrotoxic dose of gentamicin sulfate (40 mg/kg/day, i.p.) or a saline solution. Food ingestion patterns of rats were recorded every hour using a Diet Scan system and gentamicin nephrotoxicity indices were measured. The second study used rats that were fed the same diets and given a sham injection. Corticosterone was assayed to quantify the stress of the animals. Results showed that chronic gentamicin treatment leads to a decrease in food intake and flattening of the rhythms of food ingestion. Also, chow feeding and the 20% casein diet were found to be more protective against gentamicin-induced nephrotoxicity than the 55% casein diet. Therefore, while a protein-rich diet can be protective against gentamicin-induced nephrotoxicity, the present study demonstrates that a diet too high in protein might rather be harmful to the kidneys.

Feeding is organised within the 24-h of the light – dark (LD) cycle. Food is ingested in a circadian manner in nature and in laboratory animals kept under constant conditions. The circadian rhythmicity in food ingestion is driven by a biological clock located in the suprachiasmatic nuclei (SCN) of the hypothalamus. The circadian organisation of food ingestion not only allows animals to live in harmony with their environment but food intake could also act as a zeitgeber for other rhythmic functions. Lesions in the area of the SCN result in the loss of most rhythmic functions as well as to a disrupted circadian rhythmicity of food and water intake. These findings, together with observations from daytime feeding experiments conducted in nocturnal animals, suggest that food intake may serve as a temporal signal for some peripheral organs to oscillate in phase with the SCN. This paper overviews and discusses how food intake interacts with the circadian system.

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 (Hillet 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; Barshet al.2000). The present paper considers some of the animal models used to infer aspects of human obesity, with an emphasis upon their usefulness.

Sibutramine, a serotonin-noradrenaline reuptake inhibitor (SNRI), has been shown to be a safe and effective weight-loss drug. The purpose of the present study was to examine whether sibutramine has an effect on macronutrient selection in both female and male rats in addition to total food intake. Wistar rats of both sexes were divided into three groups, and each group was offered a different set of three sensorily contrasting macronutrient-specific diets, each set including carbohydrate-, protein-, and fat-rich diets. Sibutramine (10 mg/kg) was shown to consistently decrease carbohydrate and fat intake at all data points regardless of gender and diet. Intake of carbohydrate differed between male and female rats at 2 h post administration with 2.5 and 5 mg/kg of sibutramine. The effect of sibutramine on protein intake was diet- and gender-specific. All doses of sibutramine decreased total food intake regardless of gender and diet group beginning at 6 h post administration. In conclusion, sibutramine affected macronutrient selection and emphasis on dietary recommendations, as well as appropriate dosage according to gender should be considered during therapy.

Melatonin, a hormone secreted in a rhythmic manner over 24 h mainly by the pineal gland, is used to alleviate the symptoms of jetlag and treat sleeping problems. The objective of the present study was to examine the effects of a 7-h phase-shift from the natural peak of melatonin secretion on total food intake and macronutrient selection. Forty-eight adult Wistar rats of both sexes were divided in three dietary groups, each group offered a simultaneous and different choice of a carbohydrate- and a protein-rich diet. Macronutrient intakes following intraperitoneal administration of four doses of melatonin (3000, 6000, 10 000 and 15 000 pg/ml blood) at dark onset were examined. Melatonin increased short- (4 h postinjection) and long-term (12 h postinjection) nocturnal total food intake in both male and female rats, mainly with the two highest doses. This effect of melatonin was mainly due to a short-term increase of intake across all carbohydrate-rich diet preparations (dextrin/cornstarch, cornstarch, and sucrose/cornstarch) and across genders. This consistent effect of melatonin on the intake of carbohydrate-rich diets with contrasting sensory attributes rules out the possibility that melatonin acts on sensorymotor pathways, thus suggesting that melatonin's effect on food intake is controlled by the carbohydrate content of the diet. In contrast, melatonin could be affecting some sensory or motor processes peculiar to the ingestion of protein since it increased protein-rich diet intake inconsistently across the various preparations (casein, soy isolate, and egg protein) as well as genders. This evidence supports the view that melatonin acts as a time indicator, reinforcing the animals with a “night cue”, and favors predominant carbohydrate intake normally occurring at the beginning of the activity period.

Eating and drinking patterns were examined in intact and blinded adult male Sprague-Dawley rats fed a choice among isocaloric casein, sucrose/dextrin, and vegetable shortening/soybean oil diets. Weekly mean intake of all nutrients was altered in blinded rats, with increased lipid intake and decreased water intake in rats blinded for 2 weeks, lower carbohydrate but higher protein and water intakes in rats blinded for 4 weeks, while 2 weeks later blinded rats maintained high intakes of protein and water. The amplitudes of the daily rhythms for each nutrient behaved similarly to the weekly intakes. Delayed daily time of peak intake for all nutrients over successive weeks after blindness were found, indicating that the timing of peak intake free-runs. 24 h profile indicated time of day variations of nutrient intake tending to be less marked over successive weeks of blindness. Free-running animals maintained the link between carbohydrate intake and hypothalamus serotonin.

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.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.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 (p0.001) 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.In our current experimental conditions, a protective effect of high-casein diet against CsA-induced proximal tubular damage was observed in Sprague-Dawley rats.

Gentamicin-induced nephrotoxicity varies temporally, with a peak being observed when this antibiotic is administered during the resting period and a trough when given during the activity period of rats. These nychthemeral variations are modified by fasting and by restricted feeding schedules. In this study, food and water intakes of adult female Sprague-Dawley rats were measured during pretreatment (Days 1 to 5) and during treatment (Days 6 to 10) with gentamicin (80 mg/kg/day, i.p.) injected at 1300 or 0100h. A significantly higher level of serum creatinine was observed when gentamicin was administered at 1300 h compared to 0100 h, and a significantly lower creatinine clearance was found in rats treated with gentamicin at 1300 h compared to those treated with saline at the same time. Gentamicin treatment at 1300 or 0100 h resulted in a decrease in the 24-h food intake. In addition, in the gentamicin-treated group at 0100 h, the maximal food intake observed at late dark during the pretreatment period decreased during treatment, and early dark rather than late dark maximal intake occurred. Our data demonstrate that gentamicin induces a nephrotoxicity that varies temporally, and that gentamicin treatment inhibits food intake and alters its nocturnal variations.

To compare food and water intakes, adult male Wistar rats were infused during 7 days with serotonin (5-HT, 2.5 nmol/24 h) or artificial cerebrospinal fluid (CSF) in the suprachiasmatic nucleus (SCN) in a three-way selection of macronutrient-rich diets. Nocturnal energy intake from the casein-rich diet was significantly lower during infusion of 5-HT than before infusion. Decrease in nocturnal casein consumption was significant in the middle dark phase. Within the infusion period, water intake was reduced by 5-HT infusion during the early, middle and late light phase. The present results reinforce the hypothesis of a serotonergic control of water intake and provide evidence for SCN 5-HT involvement in casein-specific dietary selection.

To examine whether the diurnal rhythms of protein-rich and carbohydrate-rich diet ingestion can be altered by presenting the diets in different textural forms, adult male Wistar rats were assigned to two dietary groups. One group received a two-way choice between high-protein powder and high-carbohydrate granular (HPP-HCG) diets. In the other group the textures were reversed [high-protein granular and high-carbohydrate powder (HPG-HCP) diets]. Rats fed HPP-HCG diets selected significantly less protein (kcal) vs. rats fed HPG-HCP diets, during the 24-h and 12-h dark phase and during the 4-h early and late dark phases. Carbohydrate intakes of the two dietary groups were not significantly different. Total caloric intake for the HPG-HCP dietary group was significantly higher than that of the HPP-HCG dietary group during the 24-h and 12-h dark phase. Body weight was significantly lower in rats fed HPP-HCG diets. In conclusion, macronutrient-rich diets presented in different textural forms alter protein-rich diet ingestion and total energy intake.

Evidence for temporal variations in the nephrotoxicity of low doses of aminoglycosides were recently shown by using specific and sensitive parameters of renal toxicity. The aim of the present study was to evaluate the effect of a short period of fasting on the temporal variations in the renal toxicity of gentamicin. Twenty-eight normally fed (i.e., food and water were available ad libitum throughout the experiment) female Sprague-Dawley rats (weight, 175 to 220 g) and 28 fasted rats (i.e., only water was available during a 12-h fast before and a 24-h fast after gentamicin injection) were used. The animals were synchronized on a 14-h light, 10-h dark cycle (lights on at 0600 h) for 1 week before gentamicin administration. In July 1993, each group of animals was treated with a single intraperitoneal injection of saline (NaCl, 0.9%) or gentamicin (150 mg/kg of body weight) at either the peak (1400 h) or the trough (0200 h) of the previously determined toxicity. On day 1, the 24-h urinary excretion of beta-galactosidase, N-acetyl-beta-D-glucosaminidase, and gamma-glutamyltransferase was significantly higher in normally fed animals treated with gentamicin at 1400 h than in their time-matched controls and in normally fed animals treated at 0200 h (P < 0.01), which had normal levels of these enzymes. By contrast, the urinary excretion of these enzymes was significantly higher in both groups of gentamicin-treated, fasted rats than in their time-matched control groups (P < 0.01), reaching levels similar to those measured in normally fed rats treated at 1400 h. The accumulation of gentamicin was significantly lower in the renal cortex of normally fed rats treated at 0200 h than in rats treated at 1400 h (P < 0.05), but this time-dependent difference was not found in fasted rats treated at 0200 and 1400 h. Immunogold labeling done on ultrathin sections and observed by electron microscopy showed a similar subcellular localization of gentamicin in normally fed and fasted rats treated at either 1400 or 0200 h. These results suggest that the feeding period is of crucial importance in the temporal variations of the nephrotoxicity of gentamicin in rats.

Compared were the light-dark pattern of absolute energy intake and macronutrient selection of male Wistar rats intracerebroventricularly infused with glucagon (5 ng/h) or saline for 7 days in a three-way selection of macronutrients. Glucagon infusion induced a decrease in 24 h and nocturnal energy intake, whereas no significant change in kcal intake accompanied vehicle infusion. The decrease in kcal intake was due to a suppression of nocturnal ingestion of carbohydrate. This parameter was left unaffected with central vehicle infusion. Glucagon-infused rats had a significantly lower body weight gain than those infused with vehicle. Our study supports the hypothesis of central glucagon's suppressive effect on food intake, but reveals that the latter reflects a lower disposition to eat carbohydrate during the dark phase. The present work emphasizes the role of glucagon in the circadian regulation of carbohydrate intake.

This chapter aims to review literature on different aspects of obesity from fat-rich diets in non-human species. Usefulness of using small rodents in animal models to infer aspects of human obesity is discussed in terms of similarities and differences and how obesity is defined. The paradigm of using fat-rich diets in animal models of human obesity is explored according to its adequacy and dietary characteristics related to fatty acid composition. Physiological factors and mechanisms that can play a role in the development of obesity induced by a diet rich in fat are examined, namely the efficiency of nutrient utilization and the possible lack of inhibitory effect of fat on intake. The role of hormones such as leptin, ghrelin and insulin is discussed. Bevavioural mechanisms related to sensory-specific facilitation of eating with fat rich diets, altered feeding rhythmicity and learned eating are considered. The possible reversal of fat-rich diet induced obesity in animal models is explored. This chapter concludes with comments on appropriate design of animal studies and suggestions for future research.

Different carbohydrate sources in animal diets can affect feeding behavior. The absence of a diet standard, thus, has the potential to introduce a confounding factor into experiments. The main objective of this study, therefore, was to determine if the choice of either sucrose or fructose as the pure carbohydrate in a carbohydrate diet ration would affect feeding behavior in rats. It was found that during the light and dark phases: 1) fructose-fed rats selected significantly less energy from carbohydrate than sucrose fed rats, 2) fructose-fed rats selected more protein and lipid energy than sucrose fed rats, and 3) the total caloric intakes of the two groups were not significantly different. Differing postingestive effects of sucrose and fructose with subsequent compensatory intake may explain these results. Two different carbohydrate sources resulted in different macronutrient selection patterns, thus demonstrating the importance of the nature of dietary carbohydrate in the regulation of feeding behavior in rats.

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.

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.

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.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.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 (P0.001 [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 (P0.001 [χ(2)] for male, P=0.012 for female).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.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.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.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 (P0.001 [χIn 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.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.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.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 (χAu 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.

Analyses of rats diurnal/nocturnal feeding behaviour were made according to the caloric density of the lipid ration. Adult male Sprague-Dawley rats were simultaneously offered three pure macronutrient diet rations: protein, carbohydrate, and lipid. The last was either kept isocaloric to protein and carbohydrate rations or was hypercaloric. Measurements of the food intake were recorded at 12-h intervals with respect to the dark phase and to the light phase of the circadian cycle (24h). Rats fed the hypercaloric lipid diet ration showed a significantly higher total energy intake compared with animals fed the isocaloric lipid diet ration. Also, in the hypercaloric group, the percentage of energy ingested as protein was significantly higher during both the light and dark phases, whereas the percentage of energy ingested as carbohydrate was significantly lower during the light phase and the 24-h cycle when compared with that of the isocaloric group. These results indicate that the caloric density of the lipid diet ration has differential effects on the diurnal/nocturnal energy intake and macronutrient choice and suggest that these feeding patterns may modify the outcome of experiments using macronutrient diet rations with different caloric density.

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.

Publisher Summary The control of food intake based on the sensory properties of foods, such as flavors or textures, has been tested. It has been demonstrated that choices of foods and drinks are achieved by learning relative preferences/aversions for foods and drinks and appetite/satiety for nutrients, regardless of the source of energy. Learning is a change in the organization of an individual's behavior so that performance represents an adaptation to the external and internal environments. When sensory cues from foods (conditioned stimuli) are paired with prompt nutritional after-effects of eating (unconditioned stimuli), conditioned responses of food choice and intake can be induced. Classical conditioning and instrumental conditioning are two types of associative control of eating, in which presented relations between responses and/or stimuli result in a persisting change in behavior. In classical conditioning, first identified by Ivan Petrovich Pavlov (1927), a relatively neutral stimulus (CS) is paired with a stimulus of significant biological and behavioral change, such as food (US). Classical conditioning occurs when associations are synthesized between two neutral stimuli, meaning that the predictive relation between the CS and the US leads to a conditioned response (CR) to the CS. Most of our likes and dislikes are learned through classical conditioning.

The effect of glucagon on macronutrient selection was studied using rats. Continuous infusion of glucagon (5 ng/μl/h) into the lateral cerebral ventricle increased total caloric intake and protein selection, and decreased carbohydrate selection. Continuous infusion of glucagon subcutaneously induced similar changes. Since a hyperglycemic response to the intracranial injection of 2-deoxy-D-glucose (2DG) disappeared in rats either with bilateral lesions of the hypothalamic suprachiasmatic nucleus (SCN) (17) or with acquired (21) and congenital (10) blindness, and bilateral lesions of the SCN eliminated the hyperglucagonemic response to the 2DG-injection (19), changes in the plasma glucagon concentration after 2DG injection were examined in acquired and congenital blind rats. Consequently, it was found that the hyperglucagonemic response to 2DG was not observed in those blind rats which lacked the hyperglycemic response. In those SCN-lesioned and blind rats lacking the hyperglucagonemic response to 2DG, the protein selection was lower, and carbohydrate selection tended to be higher, than those selections found in the control rats. Considering the neural connection between the retina and the SCN, these findings suggest that glucagon may have a stimulatory effect on protein intake and a suppressive one for carbohydrate intake; and that the SCN may be involved in such a regulatory mechanism of feeding behavior through controlling the blood glucagon level.

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.

Background/Aims: Isomaltulose (α-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.

Relationships among feeding paradigm (single diet vs food selection) and arterio-venous differences (delta AV) of glucose, insulin and tryptophan were studied by measuring the temporal patterns of food intake and plasma parameters during 8 hr feeding cycles in rats. Adult male Sprague-Dawley rats were offered a single diet of fixed composition (20% casein) or a choice between two isocaloric diets (0% and 60% casein) for 2 weeks under 8-hr daily feeding conditions, food being offered during the dark cycle. Groups of animals were then killed at the beginning and at 2-hourly intervals throughout the feeding period. With both feeding paradigms, rats showed temporal patterns of energy, carbohydrate and protein intakes with a peak at the beginning and a trough at the end of the feeding period. However, in rats offered a dietary choice the intake of carbohydrate was significantly lower, and the intakes of energy and protein significantly higher than those found in rats offered a single diet. Throughout the feeding period, these differences between single and choice diets became less accentuated in the case of carbohydrate intake, but more accentuated for energy and protein intakes. Paradoxically, rats fed a choice of diets had a significantly lower weight gain than rats fed a single diet. The temporal variation of insulin secretion and tryptophan absorption varied inversely with the two diet paradigms. Moreover, in rats offered a choice of diets, macronutrient intake was significantly correlated with insulin secretion and venous glucose concentration. The opposed physiologic and metabolic responses to the feeding paradigms suggest the need for future studies to examine the possibility that such can function as synchronizers of biological rhythms.

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.

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.

The present study investigated the effect of single chow diet and two-way dietary choice between a protein-rich and a carbohydrate-rich diet ingested during free access or daytime access (08.00-16.00 h) on the rhythms of ingestion and on nocturnal levels of serum melatonin and pineal N-acetyltransferase activity in rats. Animals with free access to the single or the choice diets displayed a circadian rhythmicity of total food intake with peaks at the beginning, the middle and the end of the dark phase. Rats fed the dietary choice displayed a preference for carbohydrate at the beginning, and a preference for protein at the middle and the end of the dark phase. Under daytime feeding access, both dietary conditions resulted in only one peak of total intake at the beginning of the access period. Rats fed the choice diets on the daytime feeding schedule initially preferred carbohydrate to protein but this preference disappeared subsequently. Nocturnal peaks of serum melatonin and pineal NAT activity were lower with daytime access to dietary choice compared to ad libitum access. The results suggest that in a two-way selection of macronutrients, feeding cycle can directly act on the rhythms expressed within the pineal gland.

Previous studies have shown temporal variations in gentamicin-induced renal toxicity characterized by a peak when administered during the resting period and a trough during the active period. This time-dependent toxicity was also altered according to the macronutrient composition of dietary regimens offered to female rats. In the present study, adult female Sprague-Dawley rats were adapted to semipurified isocaloric diets containing 20% casein or soy-protein (10% fat each) or to a standard chow diet (18.1% mixed proteins; 4.5% fat). The animals were then chronically treated for 10 days with a nephrotoxic dose of gentamicin sulfate (40 mg/kg/day ip) or a saline solution administered in the middle of their resting period (1200 h) or in the middle of their activity period (0000 h). Body weights of rats injected in the middle of their resting period decreased over the last 6 days of gentamicin treatment. Total 12-h light and 12-h dark food intakes were decreased in gentamicin-treated rats. Rats fed the standard chow diet had significantly lower corticocellular regeneration, serum creatinine and blood urea nitrogen compared to those fed the casein- and soy-containing diets. The present study demonstrates that chronic gentamicin-induced renal toxicity varies temporally according to the time of administration and that a mixed protein diet containing a lower fat level can protect against gentamicin-induced nephrotoxicity.

To determine if an increase in intake at a meal before a long fast can be conditioned to food texture cues, male Sprague-Dawley rats were given a high- or low-fat diet in one texture (powder or pellet) for 1 h prior to a 12.5-h fast and in the other texture before a 3-h fast. Each group (N = 9) went through a pseudorandom sequence of four duplicates of each texture-fast pairing over 4 experimental days in each of three training trials, followed by one 4-day trial under extinction, i.e. without the difference in fast lengths between textures. Neither the high-fat group nor the low-fat group as a whole gave a clear indication of a learnt texture-cued increase in meal size before the longer fast relative to the shorter fast. However, the rats trained on the high-fat diet that had the highest intakes on the first 4 days of training showed a relative increase in the amount eaten of the texture predicting the longer fast during the third training trial, and this effect also approached statistical significance in the extinction test. These results provide some support for the conclusion that anticipatory hunger/satiety can be differentially conditioned to dietary texture cues, but only if sufficient food is eaten before a short fast to prevent the rise in hunger during longer fasts that reinforces the discriminative increase in meal size.

The only evidence for nutrient selection comes from baseline or treatment effects on nutrient intakes that are qualitatively similar when sensorily contrasting forms of each macronutrient are investigated and/or dietary compositions and strains of rat or mouse are different within or between laboratories. By that criterion the only potential case of a treatment reliably altering macronutrient selection identified in the present review of the literature is d-norfenfluramine, fluoxetine and paraventricular serotonin (5-HT) reducing the intake of dextrin-containing diets at early dark. The only clear example of reverse effects of an agonist and an antagonist on dietary intake was found with serotonergic agents. Claims for catecholaminergic or opioid involvement in protein intake and peptidergic involvement in carbohydrate intake were not substantiated. There remain the issues of which learnt macronutrient-specific postgastric actions and sensory cues from the affected diet rely on the neural pathway(s) on which the drug is acting to alter dietary selection. Until experiments address these questions, the neural bases of nutrient-specific appetites will remain unknown. Drug effects must be consistent across differently textured and flavoured versions of each macronutrient tested.

Evidence for temporal variation in the nephrotoxicity of amphotericin B was recently reported in experimental animals. The role of food in these variations was determined by studying the effect of a short fasting period on the temporal variation in the renal toxicity of amphotericin B. Twenty-eight normally fed and 28 fasted female Sprague-Dawley rats were used. Food was available ad libitum to the fed rats, while the fasted animals were fasted 12 h before and 24 h after amphotericin B injection to minimize stress for the animals. Water was available ad libitum to both groups of rats, which were maintained on a 14-h light, 10-h dark regimen (light on at 0600 h). Renal toxicity was determined by comparing the levels of excretion of renal enzyme and the serum creatinine and blood urea nitrogen (BUN) levels at the time of the maximal (0700 h) or the minimal (1900 h) nephrotoxicity after the intraperitoneal administration of a single dose of dextrose (5%; control group) or amphotericin B (50 mg/kg of body weight; treated group) to the rats. The nephrotoxicities obtained after amphotericin B administration at both times of day were compared to the nephrotoxicities observed for time-matched controls. In fed animals, the 24-h urinary excretion of N -acetyl-β- d -glucosaminidase and β-galactosidase was significantly higher when amphotericin B was injected at 0700 and 1900 h. The excretion of these two enzymes was reduced significantly ( P < 0.05) in fasting rats, and this effect was larger at 0700 h ( P < 0.05) than at 1900 h. The serum creatinine level was also significantly higher ( P < 0.05) in fed animals treated at 0700 h than in fed animals treated at 1900 h. Fasting reduced significantly ( P < 0.05) the increase in the serum creatinine level, and this effect was larger in the animals treated at 0700 h. Similar data were obtained for BUN levels. Amphotericin B accumulation was significantly higher ( P < 0.05) in the renal cortexes of fed rats than in those of fasted animals, but there was no difference according to the time of injection. These results demonstrated that fasting reduces the nephrotoxicity of amphotericin B and that food availability is of crucial importance in the temporal variation in the renal toxicity of amphotericin B in rats.

Stress is associated with significant losses in the swine industry. Seasonal changes have been shown to affect stress resistance in several species of animals. In the present study, we examined the effect of two seasons (fall or winter) on plasma insulin, cortisol, and adrenocorticotrophin hormone (ACTH) levels from fasted normal and carrier pigs for stress susceptibility when submitted to a blood-sampling stressor between 10:00 and 11:00. Comparisons were made of 10 diurnally active normal (NN) and 8 carrier (Nn) pigs reared in the fall to 9 NN and 10 Nn pigs reared in the winter. The light-dark cycle throughout the period of the experiment was 10 h light/14 h dark, with lights on from 07:00 to 17:00. Feed consisted of the traditional western Canadian swine ration consumed ad libitum. Results revealed significant season-by-genotype interactions for plasma insulin and ACTH concentrations in response to the blood-sampling stressor. The normal pigs displayed a significantly lower plasma insulin level during winter compared to the fall season. Plasma ACTH of normal pigs was 18% lower in the winter compared to the fall season, although this difference was not statistically significant. The carrier genotype, on the other hand, demonstrated higher plasma insulin concentration and lower plasma ACTH concentration in the winter compared to the fall season. Furthermore, there was a main genotype effect in plasma cortisol concentration such that the carrier pigs experienced a greater level compared to the normal genotype. Similarly, the carrier pigs had a more acute ACTH response to the blood-sampling stressor compared to the normal pigs during the fall season. Results have demonstrated that these two seasons of the year affect the response of both genotypes to a blood-sampling stressor, with the carrier genotype experiencing a more intense stress reaction in the fall season. These results further contribute to the recent research indicating that carrier pigs for stress susceptibility have a unique stress response.