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This study's objective was to evaluate the thermoregulation aspects of native goats through broken-line regression to understand the triggering of physiological responses in the homeothermy process. Data were collected from ten healthy dams of the Canindé breed once a week at hourly intervals (24 h) for eight consecutive weeks. Air temperature (AT; °C), relative humidity (RH; %) were measured and temperature-humidity index (THI) calculated. The thermoregulation parameters evaluated were: respiratory rate (RR; breaths.min-1), rectal temperature (RT; °C) and sweating rate (SR; g.m-2.h-1). All variables were subjected to analysis of variance with repeated measures over time. The hour was considered a fixed effect (00:00 h, 01:00 h, , 23:00 h), and the animal was a random effect. Multiple regression analyses were also examined using General Linear Models and Variance Inflation Factors were calculated. Broken line non-linear regressions for RR, RT and SR were examined using independent variables. The highest average for AT and RH were 35.9 °C (13:00 h) and 92.4% (04:00 h), respectively. The lowest average of TA and RH were 22.1 °C (05:00 h) and 28.0% (12:00 h), respectively. The highest average THI was 102.1 (13:00 h), and the lowest 78.0 (05:00 h). The environmental thresholds at which RR, RT and SR began to increase for AT were between 17-21 °C and RH were > 17% (RR), ≥ 21 (RT) and > 23% (SR). For THI the limits were 108.4 for RR, 78.0 for RT and 100.1 for SR. Using THI, the thermoregulatory parameters are activated in the following order: SR, RR and RT. Estimates can serve as a basis to implement heat stress mitigation and improve animal welfare strategies for native goats.
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Temperatura Corporal , Cabras , Animais , Modelos Lineares , Regulação da Temperatura Corporal , Temperatura , Umidade , Temperatura AltaRESUMO
OBJECTIVES: To evaluate the association of sleep habits with the weight status of children aged 4-6 years. METHODS: Data were obtained from the PREDI Study, a Brazilian birth cohort study. The current study was carried out in the homes of the participants during two follow-ups: 2016/17 and 2018. The participants were submitted to anthropometric assessment and demographic, socioeconomic and sleep data were obtained. The child's sleep habits were self-reported by the mother or caregiver on the day of the visit and included information on the following sleep habits during the past week: bedtime routine, rhythmicity, and separation affect determined with the Sleep Habits Inventory for Preschool Children and the Sleep Habits Inventory. Logistic regression and gamma-log regression analyses were used to examine the association of sleep habits with excess body weight of children in the two follow-ups according to sex. RESULTS: Of the 217 and 185 children included in 2016/17 and 2018, respectively, 66 (30.6%) and 48 (25.9%) had a BMI >85th percentile at 4-6 years, respectively. The median rhythmicity score was higher in children with excess body weight (p = 0.05). Adjusted analysis showed that rhythmicity was associated with excess body weight of girls at ages 4-5 years (OR = 1.42, 95% CI: 1.09-1.86, p = 0.009) and 6 years (OR = 1.32, 95% CI: 1.06-1.65, p = 0.015), even after adjustment for other important covariates. Additionally, the sleep habit "separation affect" was inversely associated with the child's BMI in boys (ß = -0.005, 95% CI: -0.010-0.000, p = 0.037). CONCLUSIONS: In the present study, rhythmicity problems were associated with increased odds of girls aged 4-6 years having excess body weight. These results are important from a public health perspective since strategies aimed at preventing excess body weight in children need to consider the child's sleep quality as a potential risk factor, especially rhythmicity.
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Índice de Massa Corporal , Qualidade do Sono , Sono , Coorte de Nascimento , Brasil/epidemiologia , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Hábitos , Humanos , MasculinoRESUMO
There is currently some understanding of the mechanisms that underpin the interactions between circadian rhythmicity and immunity, metabolism and immune response, and circadian rhythmicity and metabolism. In addition, a wealth of studies have led to the conclusion that the commensal microbiota (mainly bacteria) within the intestine contributes to host homeostasis by regulating circadian rhythmicity, metabolism, and the immune system. Experimental studies on how these four biological domains interact with each other have mainly focused on any two of those domains at a time and only occasionally on three. However, a systematic analysis of how these four domains concurrently interact with each other seems to be missing. We have analyzed current evidence that signposts a role for mitochondria as a key hub that supports and integrates activity across all four domains, circadian clocks, metabolic pathways, the intestinal microbiota, and the immune system, coordinating their integration and crosstalk. This work will hopefully provide a new perspective for both hypothesis-building and more systematic experimental approaches.
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BACKGROUND: The secretion of pituitary hormones oscillates throughout the 24-hour period, indicating that circadian clock-mediated mechanisms regulate this process in the gland. Additionally, pituitary hormone synthesis has been shown to be altered in hypo- and hyperthyroidism. Although thyroid hormones can modulate the other peripheral clocks, the interaction between thyroid hormone levels and circadian clock gene expression in the anterior pituitary has yet to be elucidated. METHODS: Male Wistar rats were divided into three groups: control, hypothyroid, and hyperthyroid. Following the experimental procedures, animals were euthanized every three hours over the course of a 24-hour period. The anterior pituitary glands were excised and processed for mRNA expression analysis by quantitative reverse transcriptase polymerase chain reaction. One- and two-way analysis of variance as well as cosinor analysis were used to evaluate the time-of-day-dependent differential expression for each gene in each experimental group and their interactions. RESULTS: Hyperthyroidism increased the mRNA expression of core clock genes and thyrotrophic embryonic factor (Tef), as well as the mesor and amplitude of brain and muscle Arnt-like protein-1 (Bmal1) and the mesor of nuclear receptor subfamily 1 (Nr1d1) group D member 1, when compared to euthyroid animals. Hypothyroidism disrupted the circadian expression pattern of Bmal1 and period circadian regulator 2 (Per2) and decreased the mesor of Nr1d1 and Tef. Furthermore, it was observed that the pituitary content of Dio2 mRNA was unaltered in hyperthyroidism but substantially elevated in hypothyroidism during the light phase. The upregulated expression was associated with an increased mesor and amplitude, along with an advanced acrophase. The gene expression of all the pituitary hormones was found to be altered in hypo- and hyperthyroidism. Moreover, prolactin (Prl) and luteinizing hormone beta subunit (Lhb) displayed circadian expression patterns in the control group, which were disrupted in both the hypo- and hyperthyroid states. CONCLUSION: Taken together, the data demonstrate that hypo- and hyperthyroidism alter circadian clock gene expression in the anterior pituitary. This suggests that triiodothyronine plays an important role in the regulation of pituitary gland homeostasis, which could ultimately influence the rhythmic synthesis and/or secretion of all the anterior pituitary hormones.
Assuntos
Ritmo Circadiano , Hipertireoidismo/metabolismo , Hipotireoidismo/metabolismo , Adeno-Hipófise/metabolismo , Hormônios Adeno-Hipofisários/metabolismo , RNA Mensageiro/metabolismo , Animais , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano/genética , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica , Hipertireoidismo/genética , Hipertireoidismo/fisiopatologia , Hipotireoidismo/genética , Hipotireoidismo/fisiopatologia , Masculino , Adeno-Hipófise/fisiopatologia , Hormônios Adeno-Hipofisários/genética , RNA Mensageiro/genética , Ratos Wistar , Tireotropina/sangue , Fatores de Tempo , Transcriptoma , Tri-Iodotironina/sangueRESUMO
Brown adipose tissue (BAT) influences energy balance through nonshivering thermogenesis, and its metabolism daily and seasonal variations are regulated by melatonin through partially known mechanisms. We evaluated the role of melatonin in BAT molecular machinery of male Control, pinealectomized (PINX), and melatonin-treated pinealectomized (PINX/Mel) adult rats. BAT was collected either every 3 hours over 24 hours or after cold or high-fat diet (HFD) acute exposure. HFD PINX animals presented decreased Dio2 expression, while HFD PINX/Mel animals showed increased Dio2, Ucp1, and Cidea expression. Cold-exposed PINX rats showed decreased Dio2 and Lhs expression, and melatonin treatment augmented Adrß3, Dio2, Ucp1, and Cidea expression. Daily profiles analyses showed altered Dio2, Lhs, Ucp1, Pgc1α, and Cidea gene and UCP1 protein expression in PINX animals, leading to altered rhythmicity under sub-thermoneutral conditions, which was partially restored by melatonin treatment. The same was observed for mitochondrial complexes I, II, and IV protein expression and enzyme activity. Melatonin absence seems to impair BAT responses to metabolic challenges, and melatonin replacement reverses this effect, with additional increase in the expression of crucial genes, suggesting that melatonin plays an important role in several key points of the thermogenic activation pathway, influencing both the rhythmic profile of the tissue and its ability to respond to metabolic challenges, which is crucial for the organism homeostasis.
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Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Melatonina/farmacologia , Animais , Temperatura Baixa , Dieta Hiperlipídica , Masculino , Pinealectomia , Ratos , Ratos WistarRESUMO
This study aimed to investigate the existence of day-night differences in the time for anesthesia and recovery in tambaqui exposed to the anesthetic eugenol and the influence of feeding time. Thus, we evaluated: (1) swimming activity; (2) food anticipatory activity (FAA) as a synchronizer of swimming activity and change to susceptibility to anesthetic; and (3) the effects of diurnal/nocturnal anesthesia exposure of fish feeding in the mid-light phase: 12:00 h (ML) and fish feeding in the mid-dark phase: 00:00 h (MD). Our findings revealed strictly nocturnal activity for tambaqui (94.2%), known as diurnal fish to date. Moreover, FAA was observed in tambaqui fed at MD, which showed a sustained increase in activity that began 2 h before feeding time and lasted until feeding. In contrast, no FAA was observed in fish fed at ML. Regarding anesthesia by day or night, the tambaqui treated with eugenol exhibited no difference in induction time. However, differences were observed in recovery times, with fish anesthetized at day recovering in 1-2 min and fish anesthetized at night recovering in 5-7 min. In short, our findings revealed for the first time the nocturnal behavior of tambaqui. These results indicated that recovery by day/night by eugenol in tambaqui has a strong dependence of behavioral patterns and the time of day.
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Anestesia , Ritmo Circadiano/fisiologia , Atividade Motora/fisiologia , Natação , Animais , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Comportamento Alimentar/fisiologia , Luz , Atividade Motora/efeitos dos fármacos , Fotoperíodo , DouradaRESUMO
Departure from normal circadian rhythmicity and exposure to atypical lighting cues has been shown to adversely affect human health and wellness in a variety of ways. In contrast, adaptation to extreme environments has led many species to alter or even entirely abandon their reliance upon cyclic environmental inputs, principally daily cycles of light and darkness. The extreme darkness, stability and isolation of cave ecosystems has made cave-adapted species particularly attractive systems in which to study the consequences of life without light and the strategies that allow species to survive and even thrive in such environments. In order to further explore these questions, we have assessed the rhythmicity of locomotion in the blind Mexican tetra, Astyanax mexicanus, under controlled laboratory conditions. Using high-resolution video tracking assays, we characterized patterns in locomotor activity and spatial tank usage for members of the surface and Pachón cave populations. Here we demonstrate that cavefish have a higher overall level of activity and use the space within the trial tank differently than surface fish. Further, Pachón cavefish show circadian rhythmicity in both activity and spatial tank usage under a 12:12 light/dark cycle. We provide further evidence that these cavefish retain a weakly light-entrainable, endogenous circadian oscillator with limited capability to sustain rhythms in activity, but not spatial tank usage, in the absence of photic cues. Finally, we demonstrate a putative behavioral "masking effect" contributing to behavioral rhythms and provide evidence that exposure to constant darkness during development may alter behavioral patterns later in life.
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Ciclos de Atividade , Comportamento Animal , Cegueira , Cavernas , Characidae/fisiologia , Sinais (Psicologia) , Ecossistema , Natação , Aclimatação , Animais , Escuridão , Luz , Fatores de Tempo , Gravação em VídeoRESUMO
Neste artigo o autor tenta mostrar uma perspectiva psicanalítica sobre o que neste momento aparece como uma prevalência excessiva de crianças pequenas na suspeita de autismo. Para isso expõe uma série de suposições sobre os possíveis motivos para o aumento deste tipo de consulta, em relação tanto aos aspectos constitucionais da criança, quanto à incidência de fatores de ordem cultural que afetam o vínculo entre pais e filhos. Estabelece a hipótese de uma forma de funcionamento da criança que denomina transtorno de subjetivação arcaica descrevendo algumas das características observadas em sua experiência clínica e apresenta um caso para ilustrar a forma peculiar de abordagem tanto da criança (aspecto intrapsíquico) quanto dos pais (aspecto intersubjetivo(AU)
In this paper the author tries to show a psychoanalytical perspective on what currently appears to be an excessive prevalence of little children suspected of autism. In order to do this, a series of hypotheses are raised about the possible reasons for the increase in this kind of consultations, related both to the child's constitutional aspects and to the incidence of cultural factors affecting the bond between parents and children. The author puts forward the hypothesis of a form of child's functioning called disorder of archaic subjectivation. He describes some of the characteristics observed in his clinical experience and presents a case to illustrate the peculiar approach of both the child (intraphsychic aspect) and the parents (intersubjective aspect)(AU)
El autor en este trabajo trata de mostrar una perspectiva psicoanalítica sobre lo que en este momento aparece como una prevalencia excesiva de niños pequeños en sospecha de autismo. Para ello se plantea una seria de hipótesis sobre los posibles motivos del aumento de este tipo de consulta, en relación tanto a aspectos constitucionales del niño, como a la incidencia de factores de orden cultural que inciden sobre el vínculo padres-hijos. Establece la hipótesis de una forma de funcionamiento en el niño que denomina trastorno de subjetivación arcaica, describiendo algunas de las características que observa en su experiencia clínica y presenta un caso para ilustrar la forma peculiar del abordaje, tanto con el niño (aspecto intrapsíquico) como con los padres (aspecto intersubjetivo)(AU)
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Criança , Psicanálise , Transtorno do Espectro Autista/psicologiaRESUMO
The objective of this study was to evaluate the alterations in sleep and circadian parameters during the aging process. The study sample comprises volunteers older than 18 up to 90 years of age that answered the Pittsburgh Sleep Quality Index (PSQI) and the Horne and Östberg circadian preference questionnaire. We observed that the shift to morningness with increasing age is associated with a significant worsening in sleep quality. We discuss that this sleep profile characterized by morningness and worse sleep quality observed in elderly, when compared to younger people, reflects not necessarily a pathological state, but an expected profile for this age group.
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Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Adulto Jovem , Sono/fisiologia , Transtornos do Sono-Vigília/fisiopatologia , Envelhecimento/fisiologia , Qualidade de Vida , Fatores de Tempo , Temperatura Corporal/fisiologia , Análise de Variância , Fatores Etários , Ritmo Circadiano/fisiologia , Estatísticas não Paramétricas , AutorrelatoRESUMO
Vertigo and dizziness are among the most common medical complaints in the emergency room, and are associated with a considerable personal and health care burden. Scarce and conflicting reports indicate those symptoms may present a seasonal distribution. This study aimed at investigating the existence of a seasonal distribution of vertigo/dizziness in a tropical region, and the correlations of these findings with climatic variables. The charts of all patients consecutively admitted between 2009 and 2012 in the emergency room of a Brazilian general hospital were reviewed. A total of 4920 cases containing these terms were sorted from a sample of 276,076 emergency records. Seasonality was assessed using Cosinor Analysis. Pearson's correlations were performed between the incidence of consultations, considering separately dizziness and vertigo and each of the predictor climatic variables of that index month. Significant seasonal patterns were observed for dizziness and vertigo in the emergency room. Vertigo was more frequent in late winter-spring, negatively correlating to humidity (r = -0.374; p = 0.013) and rainfall (r = -0.334; p = 0.020). Dizziness peaked on summer months, and positively correlated to average temperatures (r = 0.520; p < 0.001) and rainfall (r = 0.297; p = 0.040), but negatively to atmospheric pressure (r = -0.424; p = 0.003). The different seasonal patterns evidenced for dizziness and vertigo indicate possible distinct underlying mechanisms of how seasons may influence the occurrence of those symptoms.
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Ritmo Circadiano/fisiologia , Tontura/epidemiologia , Estações do Ano , Clima Tropical , Vertigem/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil , Criança , Feminino , Humanos , Umidade/efeitos adversos , Incidência , Masculino , Pessoa de Meia-Idade , Temperatura , Adulto JovemRESUMO
Background: Circadian rhythms are biological rhythms generated by an organism or group of organisms that have an intrinsic period of 24 h. Among the many variables that exhibit circadian rhythmicity, body temperature has received considerable attention. The circadian rhythm of body temperature is a well-documented physiological phenomen. Also, it has been shown that changes in heat loss via convection and radiation are primarily caused by variations in skin blood flow, with consequent changes in skin temperature. For this reason, foot temperature assumes a great importance both as indicator of equine laminitis and foot-and-mouth disease in sheep. Particularly, the foot rot, term loosely used to describe lameness associated with the bovine foot, is characterized by acute inflammation of the skin and adjacent soft tissue of the interdigital cleft or space in which the modifications of temperature assume a great importance. In fact, the regulation of body temperature is an essential component of the process of fever, which plays an important role in an organisms response to infection and disease, and its manipulation is a standard procedure in various surgical and therapeutic procedures. In this regards, the aim of this study was to evaluate the pattern of rectal temperature (RT) both in healthy Comisana sheep and in Comisana sheep affected by foot rot.Materials, Methods & Re
Background: Circadian rhythms are biological rhythms generated by an organism or group of organisms that have an intrinsic period of 24 h. Among the many variables that exhibit circadian rhythmicity, body temperature has received considerable attention. The circadian rhythm of body temperature is a well-documented physiological phenomen. Also, it has been shown that changes in heat loss via convection and radiation are primarily caused by variations in skin blood flow, with consequent changes in skin temperature. For this reason, foot temperature assumes a great importance both as indicator of equine laminitis and foot-and-mouth disease in sheep. Particularly, the foot rot, term loosely used to describe lameness associated with the bovine foot, is characterized by acute inflammation of the skin and adjacent soft tissue of the interdigital cleft or space in which the modifications of temperature assume a great importance. In fact, the regulation of body temperature is an essential component of the process of fever, which plays an important role in an organisms response to infection and disease, and its manipulation is a standard procedure in various surgical and therapeutic procedures. In this regards, the aim of this study was to evaluate the pattern of rectal temperature (RT) both in healthy Comisana sheep and in Comisana sheep affected by foot rot.Materials, Methods & Re
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Background: Circadian rhythms are biological rhythms generated by an organism or group of organisms that have an intrinsic period of 24 h. Among the many variables that exhibit circadian rhythmicity, body temperature has received considerable attention. The circadian rhythm of body temperature is a well-documented physiological phenomen. Also, it has been shown that changes in heat loss via convection and radiation are primarily caused by variations in skin blood flow, with consequent changes in skin temperature. For this reason, foot temperature assumes a great importance both as indicator of equine laminitis and foot-and-mouth disease in sheep. Particularly, the foot rot, term loosely used to describe lameness associated with the bovine foot, is characterized by acute inflammation of the skin and adjacent soft tissue of the interdigital cleft or space in which the modifications of temperature assume a great importance. In fact, the regulation of body temperature is an essential component of the process of fever, which plays an important role in an organism's response to infection and disease, and its manipulation is a standard procedure in various surgical and therapeutic procedures. In this regards, the aim of this study was to evaluate the pattern of rectal temperature (RT) both in healthy Comisana sheep and in Comisana sheep affected by foot rot. Materials, Methods & Results: This experiment was carried out on 10 clinically healthy and not pregnant female sheep, and 10 not pregnant female sheep affected by foot rot. During the experimental period, all animals were kept under a natural photoperiod (sunrise 06:30, sunset 19:00). RT was measured every 3 h intervals for 24 consecutive hours starting at 11:00 on day 1 and ending at 11:00 on day 2. A trigonometric statistical model was applied to the average values of each time series, so as to describe the periodic phenomenon analytically, by characterizing the main rhythmic parameters according to the single cosinor procedure. Four rhythmic parameters were determined: mean level, amplitude (the difference between the peak, or trough, and the mean value of a wave), acrophase (the time at which the peak of a rhythm occurs), and robustness (strength of rhythmicity). The application of the periodic model showed a circadian rhythm of RT in healthy subjects and no circadian rhytmicity of RT was observed in ill sheep. Discussion: The analysis of the results obtained under experimental conditions used in the present study indicated the existence of a circadian periodicity of rectal temperature in healthy sheep whereas no circadian oscillations of rectal temperature were revealed in sheep affected by foot rot. A simple and coherent explanation for these pathological alterations is that the set point is elevated during the rising phase and returned to normal during the later phase. Taking together, the findings of the present study, along with those of others, emphasize the concept that RT exhibits a circadian rhythm that reflect the familiar circadian patterns of endogenous source and the existence of circadian oscillations around a set point with changes in mean body temperature and an absent rhythm when temperature is modified to a new set point, as observed in sheep affected by foot rot.
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Animais , Feminino , Reto , Regulação da Temperatura Corporal , Ovinos/fisiologia , Pododermatite Necrótica dos Ovinos/diagnóstico , Claudicação Intermitente/veterináriaRESUMO
Background: Circadian rhythms are biological rhythms generated by an organism or group of organisms that have an intrinsic period of 24 h. Among the many variables that exhibit circadian rhythmicity, body temperature has received considerable attention. The circadian rhythm of body temperature is a well-documented physiological phenomen. Also, it has been shown that changes in heat loss via convection and radiation are primarily caused by variations in skin blood flow, with consequent changes in skin temperature. For this reason, foot temperature assumes a great importance both as indicator of equine laminitis and foot-and-mouth disease in sheep. Particularly, the foot rot, term loosely used to describe lameness associated with the bovine foot, is characterized by acute inflammation of the skin and adjacent soft tissue of the interdigital cleft or space in which the modifications of temperature assume a great importance. In fact, the regulation of body temperature is an essential component of the process of fever, which plays an important role in an organisms response to infection and disease, and its manipulation is a standard procedure in various surgical and therapeutic procedures. In this regards, the aim of this study was to evaluate the pattern of rectal temperature (RT) both in healthy Comisana sheep and in Comisana sheep affected by foot rot.Materials, Methods & Re
Background: Circadian rhythms are biological rhythms generated by an organism or group of organisms that have an intrinsic period of 24 h. Among the many variables that exhibit circadian rhythmicity, body temperature has received considerable attention. The circadian rhythm of body temperature is a well-documented physiological phenomen. Also, it has been shown that changes in heat loss via convection and radiation are primarily caused by variations in skin blood flow, with consequent changes in skin temperature. For this reason, foot temperature assumes a great importance both as indicator of equine laminitis and foot-and-mouth disease in sheep. Particularly, the foot rot, term loosely used to describe lameness associated with the bovine foot, is characterized by acute inflammation of the skin and adjacent soft tissue of the interdigital cleft or space in which the modifications of temperature assume a great importance. In fact, the regulation of body temperature is an essential component of the process of fever, which plays an important role in an organisms response to infection and disease, and its manipulation is a standard procedure in various surgical and therapeutic procedures. In this regards, the aim of this study was to evaluate the pattern of rectal temperature (RT) both in healthy Comisana sheep and in Comisana sheep affected by foot rot.Materials, Methods & Re