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BACKGROUND: Disrupted circadian rhythms may result from a misalignment between the environmental cycles (due to shift work, sleep restriction, feeding at an unusual time of day) and endogenous rhythms or by physiological aging. Among the numerous adverse effects, disrupted rhythms affect the brain-gut axis, contributing to the pathogenesis of several diseases in the gastrointestinal tract, for example, abdominal pain, constipation, gastric dyspepsia, inflammatory bowel disease, irritable bowel syndrome, and others. METHODS: This study evaluated the rat gastric emptying, gastrointestinal motility, a clock gene, gut hormones, and the neuron activity on the nucleus of tractus solitarius (NTS), area postrema (AP), and the dorsal motor nucleus of the vagus (DMV) in rats with restricted food access to the rest phase for 4 weeks. KEY RESULTS: Our results show that food restricted to the rest light period disturbed the expression pattern of a series of transcripts, including metabolic and circadian regulation. Also, the secretion of gastrointestinal hormones, gastric emptying, intestinal motility, and NTS, AP, and DMV activity were altered. CONCLUSIONS & INFERENCES: These data indicate the importance of the time of the day food is ingested on the regulation of energy balance and the endocrine activity of the stomach and small intestine, emphasizing the importance of food as a powerful circadian synchronizer and an essential factor for the triggering of gastrointestinal diseases and metabolic problems. These findings offer a novel clue regarding the obesity-promoting effect attributed to feeding time and open the possibility of treating this and other intestinal disorders.
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Gastroenteropatias , Hormônios Gastrointestinais , Ratos , Animais , Estômago , Nervo Vago/fisiologia , Ritmo Circadiano/fisiologia , Hormônios Gastrointestinais/fisiologia , Neurônios , Gastroenteropatias/metabolismoRESUMO
Short sleep is linked to disturbances in glucose metabolism and may induce a prediabetic condition. The biological clock in the suprachiasmatic nucleus (SCN) regulates the glucose rhythm in the circulation and the sleep-wake cycle. SCN vasopressin neurons (SCNVP) control daily glycemia by regulating the entrance of glucose into the arcuate nucleus (ARC). Thus, we hypothesized that sleep delay may influence SCN neuronal activity. We, therefore, investigated the role of SCNVP when sleep is disrupted by forced locomotor activity. After 2 h of sleep delay, rats exhibited decreased SCNVP neuronal activity, a decrease in the glucose transporter GLUT1 expression in tanycytes lining the third ventricle, lowered glucose entrance into the ARC, and developed hyperglycemia. The association between reduced SCNVP neuronal activity and hyperglycemia in sleep-delayed rats was evidenced by injecting intracerebroventricular vasopressin; this increased GLUT1 immunoreactivity in tanycytes, thus promoting normoglycemia. Following sleep recovery, glucose levels decreased, whereas SCNVP neuronal activity increased. These results imply that sleep-delay-induced changes in SCNVP activity lead to glycemic impairment, inferring that disruption of biological clock function might represent a critical step in developing type 2 diabetes.
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Diabetes Mellitus Tipo 2 , Hiperglicemia , Ratos , Animais , Transportador de Glucose Tipo 1/metabolismo , Ritmo Circadiano/fisiologia , Diabetes Mellitus Tipo 2/metabolismo , Núcleo Supraquiasmático/fisiologia , Sono , Glucose/metabolismo , Hiperglicemia/metabolismo , Vasopressinas/metabolismoRESUMO
Children and adolescents are high consumers of Western diets (rich in fat and sugars), which is a risk factor for overweight and obesity. Moreover, the presence of anxiety and depression among this population has increased significantly. This study explores in young postweaning rats the association between Western diet consumption and the development of metabolic and behavioral disturbances. At postnatal day (PN) 24, Wistar rats of both sexes were weaned and assigned to a control or cafeteria diet (CAF) group. After short-term exposure, a group of rats was euthanized at PN31 to obtain abdominal fat pads and blood samples. Another group of rats was tested in the open-field test, splash test, anhedonia test, and social play across 11 days (PN32-42). The CAF groups exhibited a significantly high level of body fat, serum glucose, triglycerides, leptin, and HOMA index when compared to the control groups. Only CAF males exhibited anxiety-like and depression-like behavior. Present results indicate that postweaning short-term exposure to a CAF diet has immediate detrimental effects on metabolism in both sexes. However, only CAF males showed mood disturbances. This study provides evidence that a CAF diet exerts immediate effects on behavior and metabolism in the postweaning period and that sexes present differential vulnerability.
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Dieta , Obesidade , Feminino , Ratos , Masculino , Animais , Ratos Wistar , Obesidade/metabolismo , Ansiedade , Transtornos de AnsiedadeRESUMO
Sugar solutions promote hedonic feeding and increase the risk of obesity and binge-type behavior. In rodents, ingestion of sugar solutions enhances dopamine release to mesolimbic regions, suggesting changes in hedonic intake and brain reward processes. Moreover, dopaminergic D2R/D3R receptors contribute to the hedonic intake of palatable solutions. Although the experimental evidence indicate that the dopaminergic D4 receptor (D4R) modulates feeding at homeostatic levels, it is currently unknown whether D4R also regulate the hedonic intake of sugar solutions. In this study, we evaluated the effect of the central blockade of D4R on the consumption of a 20% sucrose solution, the drinking microstructure parameters, and levels of locomotor activity in sated rats. In the first experiment, male Wistar rats were daily exposed to a 20% sugar solution in the first hour of the light phase of the light:dark cycle. On day 10, rats received i.c.v injections of the D4R antagonist, L-745870 (0, 1 or 2 µg/5 µl) and sucrose consumption and drinking microstructure parameters (latency to start drinking, bouts, drinking duration, bout size, inter-bout interval, time in activity and time in resting) were evaluated. In the second experiment, rats were trained to receive the 20% sucrose solution as described in experiment 1. On day 10, after the 1 h of sucrose access, the rats were placed in the open field for 5-min (habituation phase). Then, rats received i.c.v injections of L-745870 (0, 1 or 2 µg/ 5 µl), and were placed again in the open-field test for 10-min (pharmacological phase). The number or crosses trough squares and number of rears were scored for both the habituation and pharmacological phase. Here we found that administration of L-745870 decreased the consumption of sucrose in a dose-depended manner. Moreover, L-745870-treated rats displayed microstructural changes, including greater number of bouts and reduced drinking duration, bout size and inter-bout intervals. Furthermore, the number of crosses and number of rears in the open field test remained unchanged for habituation and pharmacological phase. Finally, present findings suggest that D4R modulates the consumption of sugar solutions by alteration of hedonic responses, but the contribution of homeostatic systems is discussed. These results open perspectives for the potential use of the D4R antagonists for treating obesity or binge-eating behavior.
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Inhabitants of urban areas are constantly exposed to light at night, which is an important environmental factor leading to circadian disruption. Streetlights filtering light through the windows and night dim light lamps are common sources of dim light at night (DLAN). The female population is susceptible to circadian disruption. The present study is aimed to determine the impact of DLAN on female Wistar rats circadian rhythms, metabolism, reproductive physiology, and behavior. After 5 weeks of DLAN exposure daily, oscillations in activity and body temperature of female rats are abolished. DLAN also decreases nocturnal food ingestion, which results in a diminishment in total food consumption. These alterations in the temporal organization of the body are associated with a significant decrease in melatonin plasmatic levels, reproductive disruptions, decreased exploration times, and marked anhedonia. This study highlights the importance of avoiding exposure to light at night, even at low intensities, to maintain the circadian organization of physiology, and denotes the great necessity of increasing the studies in females since the sexual dimorphism within the effects of desynchronizing protocols has been poorly studied.
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Atividade Motora , Fotoperíodo , Ratos , Feminino , Animais , Atividade Motora/fisiologia , Ratos Wistar , Ritmo Circadiano/fisiologia , LuzRESUMO
Eating during the rest phase is associated with metabolic syndrome, proposed to result from a conflict between food consumption and the energy-saving state imposed by the circadian system. However, in nocturnal rodents, eating during the rest phase (day-feeding, DF) also implies food intake during light exposure. To investigate whether light exposure contributes to DF-induced metabolic impairments, animals receive food during the subjective day without light. A skeleton photoperiod (SP) is used to entrain rats to a 12:12 cycle with two short light pulses framing the subjective day. DF-induced adiposity is prevented by SP, suggesting that the conflict between light and feeding stimulates fat accumulation. However, all animals under SP conditions develop glucose intolerance regardless of their feeding schedule. Moreover, animals under SP with ad libitum or night-feeding have increased adiposity. SP animals show a delayed onset of the daily rise in body temperature and energy expenditure and shorter duration of nighttime activity, which may contribute to the metabolic disturbances. These data emphasize that metabolic homeostasis can only be achieved when all daily cycling variables are synchronized. Even small shifts in the alignment of different metabolic rhythms, such as those induced by SP, may predispose individuals to metabolic disease.
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Intolerância à Glucose , Fotoperíodo , Ratos , Animais , Adiposidade , Comportamento Alimentar , Ritmo Circadiano , Intolerância à Glucose/etiologia , Obesidade/etiologia , EsqueletoRESUMO
Light at night is an emergent problem for modern society. Rodents exposed to light at night develop a loss of circadian rhythms, which leads to increased adiposity, altered immune response, and increased growth of tumors. In female rats, constant light (LL) eliminates the estrous cycle leading to a state of persistent estrus. The suprachiasmatic nucleus (SCN) drives circadian rhythms, and it interacts with the neuroendocrine network necessary for reproductive function. Timed restricted feeding (RF) exerts a powerful entraining influence on the circadian system, and it can influence the SCN activity and can restore rhythmicity or accelerate re-entrainment in experimental conditions of shift work or jet lag. The present study explored RF in female rats exposed to LL, with the hypothesis that this cyclic condition can rescue or prevent the loss of daily rhythms and benefit the expression of the estrous cycle. Two different feeding schedules were explored: 1. A 12-h food/12-h fasting schedule applied to arrhythmic rats after 3 weeks in LL, visualized as a rescue strategy (LL + RFR, 3 weeks), or applied simultaneously with the first day of LL as a preventive strategy (LL + RFP, 6 weeks). 2. A 12-h window of food intake with food given in four distributed pulses (every 3 h), applied after 3 weeks in LL, as a rescue strategy (LL + PR, 3 weeks) or applied simultaneously with the first day of LL as a preventive strategy (LL + PP, 6 weeks). Here, we present evidence that scheduled feeding can drive daily rhythms of activity and temperature in rats exposed to LL. However, the protocol of distributed feeding pulses was more efficient to restore the day-night activity and core temperature as well as the c-Fos day-night change in the SCN. Likewise, the distributed feeding partially restored the estrous cycle and the ovary morphology under LL condition. Data here provided indicate that the 12-h feeding/12-h fasting window determines the rest-activity cycle and can benefit directly the circadian and reproductive function. Moreover, this effect is stronger when food is distributed along the 12 h of subjective night.
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Introducción: La Organización Mundial de la Salud (OMS) propuso que el porcentaje de cesáreas debería ser entre un 10 y 15%. Sin embargo, en los últimos años, a nivel mundial, se ha visto un aumento en su realización. El objetivo de este estudio fue describir la población de embarazadas en Chile durante los años 2016-2019 que tuvieron parto vaginal (PV) o cesárea de no emergencia (CNE), y compararlos entre servicio público y privado. Material y Método: Estudio ecológico realizado en embarazadas que se sometieron a CNE o PV en Chile entre los años 2016-2019. Se obtuvieron datos del Departamento de estadística e información de Salud. No se requirió comité de ética. Resultados: Durante el periodo estudiado hubo 57,60% (339.592) de PV y 42,39% (249.925) de CNE. En el sistema público hubo una diferencia de 54,94% (187.046) de PV por sobre el sistema privado. Mientras que la diferencia de CNE en el sistema privado fue un 10,06% (25.153) por sobre el sistema público. Discusión: Durante los cuatro años, las PV superaron a las CNE, sin embargo, las CNE representaron más del 40% del total de nacimientos, superando ampliamente las recomendaciones de la OMS. Las falencias a nivel nacional en el sistema de clasificación, y en la recopilación de datos limitan el desarrollo de estudios más acabados. Conclusión: Para enfrentar las altas cifras de CNE, es necesario unificar, ampliar y regularizar un base de datos nacional que dé paso a la creación de guías y protocolos que limiten el uso mal justificado de CNE.
Introduction: The World Health Organization (WHO) proposed that the percentage of caesarean sections should be between 10 and 15%. However, in recent years, worldwide, there has been an increase in its realization. The objective of this study was to describe the population of pregnant women in Chile during the years 2016-2019 who had a vaginal delivery (VD) or non-emergency cesarean section (NECS), and to compare them between public and private services. Material and Method: Ecological study carried out in pregnant women who underwent NECS or VD in Chile between the years 2016-2019. Data were obtained from the Department of Statistics and Health Information. No ethics committee was required. Results: During the studied period there were 57.60% (339,592) of VD and 42.39% (249,925) of NECS. In the public system there was a difference of 54.94% (187,046) of VD over the private system. While the difference of NECS in the private system was 10.06% (25,153) over the public system. Discussion: During the four years, VD exceeded NECS, however, NECS represented more than 40% of all births, far exceeding the WHO recommendations. Shortcomings at the national level in the classification system and in data collection limit the development of more complete studies. Conclusion: To face the high numbers of NECS, it is necessary to unify, expand and regularize a national database that gives way to the creation of guides and protocols that limit the poorly justified use of NECS.
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Humanos , Feminino , Gravidez , Cesárea/estatística & dados numéricos , Parto Normal/estatística & dados numéricos , Chile/epidemiologia , Saúde Pública , Epidemiologia Descritiva , Instituições Privadas de Saúde , HospitaisRESUMO
The mechanisms underlying food anticipatory activity are still poorly understood. Here we explored the role of oxytocin (OT) and the protein c-Fos in the supraoptic nucleus (SON), medial (PVNm) and posterior (PVNp) regions of the paraventricular hypothalamic nucleus. Adult rats were assigned to one of four groups: scheduled restricted feeding (RF), ad libitum (AL), fasting after restricted feeding (RF-F), to explore the possible persistence of oscillations, or ad libitum fasted (AL-F). In the SON and in the PVNm, OT cells were c-Fos positive after food intake; in contrast, OT cells in the PVNp showed c-Fos activation in anticipation to food access, which persisted in RF-F subjects. We conclude that OT and non-OT cells of the SON and PVNm may play a role as recipients of the entraining signal provided by food intake, whereas those of the PVNp which contain motor preautonomic cells that project to peripheral organs, may be involved in the hormonal and metabolic anticipatory changes in preparation for food presentation and thus, may be part of a link between central and peripheral oscillators. In addition, due to their persistent activation they may participate in the neuronal network for the clock mechanism that leads to food entrainment.
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Ritmo Circadiano/fisiologia , Jejum/fisiologia , Ocitocina/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Animais , Ingestão de Alimentos/fisiologia , Masculino , Ratos Wistar , Fatores de TempoRESUMO
Circadian rhythms are generated endogenously with a period of approximately 24h. Studies carried out during the last decade indicate that the circadian system develops before birth, and that the suprachiasmatic nucleus, a structure that is considered the mammalian circadian clock, is present in primates from the middle of pregnancy. Recent evidence shows that the infants' circadian system is sensitive to light from very early stages of development; it has also been proposed that low-intensity lighting can regulate the developing clock. After birth there is a progressive maturation of the outputs of the circadian system with marked rhythms in sleep-wake phenomena and hormone secretion. These facts express the importance of circadian photic regulation in infants. Thus, the exposure of premature babies to light/dark cycles results in a rapid establishment of activity/rest patterns, which are in the light-dark cycle. With the continuous study of the development of the circadian system and the influence on human physiology and disease, it is anticipated that the application of circadian biology will become an increasingly important component in the perinatal care.
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Ritmo Circadiano , Núcleo Supraquiasmático , Animais , Humanos , Lactente , PrimatasRESUMO
Objetivo: Describir y comparar las manifestaciones clínicas en pacientes adultos diagnosticados con Síndrome de Sjögren primario (SSp) a edad menor o igual a 35 años versus mayores a 35 años. Materiales y métodos: Se incluyeron pacientes mayores de 18 años de edad, con diagnóstico de SSp de acuerdo a los criterios de clasificación ACR - EULAR 2002/2016, registrados en la base de datos GESSAR (Grupo de Estudio Síndrome de Sjögren Sociedad Argentina de Reumatología). Resultados: Se incluyeron 665 pacientes. Cien (15,04%) con edad al diagnóstico ≤ 35 años, 92% mujeres. El promedio de edad del grupo > 35 años, fue de 54 + 11 años, 96% mujeres. Se encontraron diferencias estadísticamente significativas entre < 35 años vs > 35 años, en xeroftalmia (90,72% vs 95,64%, p: 0,04) y xerodermia (42,35% vs 57,36%, p: 0,03) y en los siguientes dominios del ESSDAI (EULAR Activity Index for primary Sjögren's syndrome): sistema nervioso periférico (4,05 vs 11,32, p: 0,03), respiratorio (6% vs 15,40%, p: 0,01) y renal (6% vs 1,59%, p: 0,02). Conclusión: Nuestro estudio sugiere un menor compromiso glandular en pacientes con SSp diagnosticados a menor edad, sin un patrón diferencial característico en cuanto al compromiso sistémico.
Objective: To describe and compare the clinical manifestations, in adult patients diagnosed with primary Sjögren's Syndrome at age less than or equal to 35 years versus those over 35 years of age. Materials and Methods: We analyzed the data of patients older than 18 years, with diagnosis of primary Sjögren's syndrome (American - European criteria 2002), included in the GESSAR database (Sjögren Syndrome Study Group of the Argentine Society of Rheumatology). Results: 665 patients were included. One hundred of them with an age at diagnosis less than or equal to 35 years and with a mean age at diagnosis of 29 + 4 years, 92% of them women. The average age at diagnosis of the group over 35 years was 54 + 11 years, 96% women. Statistically significant differences were found between less than or equal to 35 years vs over 35 years, in xerophthalmia (90.72% vs 95.64%, p: 0.04) and xeroderma (42.35% vs 57.36% , p: 0.03), and in the following domains of ESSDAI (EULAR Activity Index for primary Sjögren's syndrome): peripheral nervous system (4.05 vs 11.32, p: 0.03), respiratory (6% vs 15.40%, p: 0.01) and renal (6% vs 1.59%, p: 0.02). Conclusion: Our study suggests less glandular involvement in patients with pSS diagnosed at a younger age, without a characteristic differential pattern regarding systemic involvement.
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Síndrome de Sjogren , Sinais e Sintomas , Fatores EtáriosRESUMO
STUDY OBJECTIVES: Individuals ailing from night eating syndrome (NES) consume more than 25% of their daily food intake during the normal sleep time, delaying their sleep or waking up in the middle of the night to eat. This study explored two experimental conditions resembling NES in Wistar rats by offering palatable food during the sleep phase, alone or combined with sleep delay. Also we explored their impact on addiction-like changes in the brain and behavior. METHODS: Experiment 1 explored the brain response after a first NES-like event; experiment 2 and 3 explored addiction-like behaviors c-Fos and FosB/ΔFosB in corticolimbic regions after 4 weeks exposition to NES-like conditions and after one week of withdrawal, respectively. For all 3 experiments 6 experimental groups were used: 1. Control; 2. Restricted access (1 h) to high-sugar diet (HSD) or to 3. high-fat diet (HFD); 4., Sleep delay for 4 h (SD) (from ZT0-ZT4, rats using slow rotating wheels); 5. SD + HSD; 6. SD + HFD. RESULTS: A first event of eating a palatable diet with or without SD was sufficient to stimulate c-Fos and ΔFosB. Along 4 weeks of exposure to the palatable diets rats exhibited escalation and binge eating, which was highest for the HFD. At this stage, SD did not influence behavioral changes nor the neuronal response. After one-week in withdrawal, rats exhibited craving and effort to obtain their palatable diet. The brains of rats previously exposed to sleep delay maintained high levels of FosB/ΔFosB in the accumbens shell and high c-Fos activation in the insular cortex. CONCLUSIONS: In our experimental models of NES-like a HFD in the sleep phase and SD are risk factors to develop binge eating and addiction-like behaviors.
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Comportamento Alimentar , Síndrome do Comer Noturno , Animais , Encéfalo , Ingestão de Alimentos , Modelos Teóricos , Ratos , Ratos WistarRESUMO
In mammals, time and metabolism are tightly coupled variables; this relationship can be illustrated by numerous examples, such as the circadian variation in food intake or the circadian response to a glucose bolus. We review evidence that the interaction between the suprachiasmatic nucleus and the arcuate nucleus plays a key role in the execution of these functions. The nuclei are reciprocally connected via different projections, and this interaction provides an ideal anatomical framework to modify the temporal output of the hypothalamus to metabolic organs as a consequence of the feedback from the periphery. The suprachiasmatic nucleus-arcuate nucleus relationship is essential to integrate metabolic information into the circadian system and thus adapt circadian rhythms in core body temperature, locomotor activity, food intake, and circulating molecules such as glucose and corticosterone. With the rise in obesity-associated diseases in the world population, gaining knowledge about this relationship, and the consequences of disturbing this liaison, is essential to understand the pathogenesis of obesity.
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Núcleo Arqueado do Hipotálamo/fisiologia , Ritmo Circadiano/fisiologia , Núcleo Supraquiasmático/fisiologia , Feminino , Humanos , MasculinoRESUMO
Night-workers, transcontinental travelers and individuals that regularly shift their sleep timing, suffer from circadian desynchrony and are at risk to develop metabolic disease, cancer, and mood disorders, among others. Experimental and clinical studies provide evidence that food intake restricted to the normal activity phase is a potent synchronizer for the circadian system and can prevent the detrimental metabolic effects associated with circadian disruption. As an alternative, we hypothesized that a timed piece of chocolate scheduled to the onset of the activity phase may be sufficient stimulus to synchronize circadian rhythms under conditions of shift-work or jet-lag. In Wistar rats, a daily piece of chocolate coupled to the onset of the active phase (breakfast) accelerated re-entrainment in a jet-lag model by setting the activity of the suprachiasmatic nucleus (SCN) to the new cycle. Furthermore, in a rat model of shift-work, a piece of chocolate for breakfast prevented circadian desynchrony, by increasing the amplitude of the day-night c-Fos activation in the SCN. Contrasting, chocolate for dinner prevented re-entrainment in the jet-lag condition and favored circadian desynchrony in the shift-work models. Moreover, chocolate for breakfast resulted in low body weight gain while chocolate for dinner boosted up body weight. Present data evidence the relevance of the timing of a highly caloric and palatable meal for circadian synchrony and metabolic function.
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Desjejum/fisiologia , Chocolate , Síndrome do Jet Lag/prevenção & controle , Transtornos do Sono do Ritmo Circadiano/prevenção & controle , Animais , Peso Corporal/fisiologia , Relógios Circadianos/fisiologia , Ritmo Circadiano/fisiologia , Modelos Animais de Doenças , Humanos , Síndrome do Jet Lag/fisiopatologia , Refeições/fisiologia , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Jornada de Trabalho em Turnos/efeitos adversos , Transtornos do Sono do Ritmo Circadiano/etiologia , Transtornos do Sono do Ritmo Circadiano/fisiopatologia , Núcleo Supraquiasmático/metabolismo , Aumento de Peso/fisiologiaRESUMO
Restricted intermittent food access to palatable food (PF) induces addiction-like behaviors and plastic changes in corticolimbic brain areas. Intermittent access protocols normally schedule PF to a fixed time, enabling animals to predict the arrival of PF. Because outside the laboratory the presence of PF may occur in a random unpredictable manner, the present study explored whether random access to PF would stimulate similar addiction-like responses as observed under a fixed scheduled. Rats were randomly assigned to a control group without chocolate access, to ad libitum access to chocolate, to fixed intermittent access (CH-F), or to random unpredictable access (CH-R) to chocolate. Only the CH-F group developed behavioral and core temperature anticipation to PF access. Both groups exposed to intermittent access to PF showed binge eating, increased effort behaviors to obtain chocolate, as well as high FosB/ΔFosB in corticolimbic areas. Moreover, FosB/ΔFosB in all areas correlated with the intensity of binge eating and effort behaviors. We conclude that both conditions of intermittent access to PF stimulate addiction-like behaviors and FosB/ΔFosB accumulation in brain reward areas; while only a fixed schedule, which provides a time clue, elicited anticipatory activation, which is strongly associated with craving behaviors and may favor relapse during withdrawal.
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Antecipação Psicológica , Comportamento Aditivo/psicologia , Comportamento Alimentar/psicologia , Privação de Alimentos , Animais , Química Encefálica , Bulimia , Chocolate , Alimentos , Masculino , Proteínas Proto-Oncogênicas c-fos/análise , Ratos , Ratos WistarRESUMO
Shift-work and exposure to light at night lead to circadian disruption, which favors the use of alcohol and may be a risk factor for development of addictive behavior. This study evaluated in two experimental models of circadian disruption behavioral indicators of elevated alcohol intake and looked for ΔFosB, which is a transcription factor for neuronal plasticity in corticolimbic structures. Male Wistar rats were exposed to experimental shift-work (AR) or to constant light (LL) and were compared with a control group (LD). After 4 weeks in their corresponding conditions, control LD rats remained rhythmic, AR rats exhibited a loss of day-night patterns in the brain and the LL rats showed arrhythmicity in general activity and day-night PER1 patterns in corticolimbic structures. During 12 days of exposure to 10 percent alcohol solution, the AR group showed daily increased alcohol intake while LD and LL rats ingested similar amounts. After 72 h of alcohol deprivation, AR and LL rats increased alcohol intake in a binge-like test; this could be due not only to circadian disruption but also to stress and/or anxiety developed from the AR and LL manipulations. Associated to the increased alcohol intake, the AR and LL rats had significant accumulation of ΔFosB in the nucleus accumbens shell and decreased ΔFosB in the infralimbic cortex. Data here reported confirm that the disruption of temporal patterns favors the increased alcohol consumption and that this is associated with a differential accumulation of ΔFosB which may favor the development of addictive behavior.
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Consumo de Bebidas Alcoólicas , Encéfalo/efeitos dos fármacos , Depressores do Sistema Nervoso Central/farmacologia , Ritmo Circadiano , Etanol/farmacologia , Proteínas Proto-Oncogênicas c-fos/efeitos dos fármacos , Jornada de Trabalho em Turnos , Animais , Ansiedade/metabolismo , Comportamento Animal , Encéfalo/metabolismo , Núcleo Central da Amígdala/efeitos dos fármacos , Núcleo Central da Amígdala/metabolismo , Depressores do Sistema Nervoso Central/administração & dosagem , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Etanol/administração & dosagem , Plasticidade Neuronal , Núcleo Accumbens/efeitos dos fármacos , Núcleo Accumbens/metabolismo , Proteínas Circadianas Period/metabolismo , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Distribuição Aleatória , Ratos , Autoadministração , Estresse Psicológico/metabolismo , Núcleo Supraquiasmático/efeitos dos fármacos , Núcleo Supraquiasmático/metabolismoRESUMO
Introduction: The purpose of this in vitro study was to assess the effects of anatomic root levels, different adhesive strategies and cementation system on bond strength (BS), nano leakage (NL) and degree of conversion (DC) after fiber posts cementation. Methods and Materials: Sixty-six roots of human premolars were endodontically prepared and divided according to the combination of adhesive application technique (manual passive, manual active and active vibratory) and the cementation system (Adper Single Bond 2/RelyX ARC [SBAR] and Single Bond Universal/RelyX Ultimate [SBUL]). Specimens were transversally sectioned into six 1-mm-thick serial slices, which were subjected to BS testing (n=7), to NL analysis using scanning electron microscopy (SEM) after slice immersion in silver nitrate (n=2), and micro-Raman spectroscopy for DC (n=2). Data were analyzed using two-way ANOVA and Bonferroni post-hoc test (α=5%). Results: Bond strength values significantly increased with active vibratory application technique (P<0.001), no significant difference was noted between adhesive systems. The cementation system Single Bond Universal/RelyX Ultimate demonstrated the lowest nano leakage values (P<0.05). The manual active and vibratory application techniques showed statistically higher degree of conversion values than the manual passive technique at the coronal and medium thirds (P<0.05); and the lowest results were observed with manual passive application to Single Bond Universal/RelyX Ultimate (P=0.016). Conclusion: The study concluded that techniques with active application (vibratory and manual) resulted in higher bond strength values. The mode of adhesive application influence the results.
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Escherichia coli strains that are able to colonize outside of the gastrointestinal tract are classified as extraintestinal pathogenic E. coli (ExpEC). A 6.5 female German shepherd dog with history of fever and hematuria was submitted for necropsy. Extensive transmural hemorrhagic cystitis with necrotizing vasculitis was identified in the urinary bladder. Multifocal thrombosis and intralesional bacteria were seen in the kidneys, liver, spleen and brain. E. coli O88:H4 was isolated in pure culture from the urinary bladder and other organs. This strain carried the virulence genes cnf-1, sfa, fim, hlyD and PapGIII which are associated with ExpEC strains.(AU)
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Animais , Cães , Cães/sangue , Cães/microbiologia , Cistite/microbiologia , Cistite/patologia , Escherichia coli/patogenicidade , Escherichia coli Extraintestinal Patogênica/patogenicidadeRESUMO
Escherichia coli strains that are able to colonize outside of the gastrointestinal tract are classified as extraintestinal pathogenic E. coli (ExpEC). A 6.5 female German shepherd dog with history of fever and hematuria was submitted for necropsy. Extensive transmural hemorrhagic cystitis with necrotizing vasculitis was identified in the urinary bladder. Multifocal thrombosis and intralesional bacteria were seen in the kidneys, liver, spleen and brain. E. coli O88:H4 was isolated in pure culture from the urinary bladder and other organs. This strain carried the virulence genes cnf-1, sfa, fim, hlyD and PapGIII which are associated with ExpEC strains.
Assuntos
Animais , Cães , Cistite/microbiologia , Cistite/patologia , Cães/microbiologia , Cães/sangue , Escherichia coli Extraintestinal Patogênica/patogenicidade , Escherichia coli/patogenicidadeRESUMO
NEW FINDINGS: What is the central question of this study? What are the factors influencing day-night variations in postprandial triglycerides? What is the main finding and its importance? Rats show low postprandial plasma triglyceride concentrations early in the active period that are attributable to a higher uptake by skeletal muscle and brown adipose tissue. We show that these day-night variations in uptake are driven by the suprachiasmatic nucleus, probably via a Rev-erbα-mediated mechanism and independent of locomotor activity. These findings highlight that the suprachiasmatic nucleus has a major role in day-night variations in plasma triglycerides and that disturbances in our biological clock might be an important risk factor contributing to development of postprandial hyperlipidaemia. Energy metabolism follows a diurnal pattern, mainly driven by the suprachiasmatic nucleus (SCN), and disruption of circadian regulation has been linked to metabolic abnormalities. Indeed, epidemiological evidence shows that night work is a risk factor for cardiovascular disease, and postprandial hyperlipidaemia is an important contributor. Therefore, the aim of this work was to investigate the factors that drive day-night variations in postprandial triglycerides (TGs). Intact and SCN-lesioned male Wistar rats were subjected to an oral fat challenge during the beginning of the rest phase (day) or the beginning of the active phase (night). The plasma TG profile was evaluated and tissue TG uptake assayed. After the fat challenge, intact rats showed lower postprandial plasma TG concentrations early in the night when compared with the day. However, no differences were observed in the rate of intestinal TG secretion between day and night. Instead, there was a higher uptake of TG by skeletal muscle and brown adipose tissue early in the active phase (night) when compared with the rest phase (day), and these variations were abolished in rats bearing bilateral SCN lesions. Rev-erbα gene expression suggests this as a possible mediator of the mechanism linking the SCN and day-night variations in TG uptake. These findings show that the SCN has a major role in day-night variations in plasma TGs by promoting TG uptake into skeletal muscle and brown adipose tissue. Consequently, disturbance of the biological clock might be an important risk factor contributing to the development of hyperlipidaemia.