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1.
Nat Commun ; 12(1): 1516, 2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33750795

RESUMO

Mild cold acclimation for 10 days has been previously shown to markedly improve insulin sensitivity in patients with type 2 diabetes. Here we show in a single-arm intervention study (Trialregister.nl ID: NL4469/NTR5711) in nine patients with type 2 diabetes that ten days of mild cold acclimation (16-17 °C) in which observable, overt shivering was prevented, does not result in improved insulin sensitivity, postprandial glucose and lipid metabolism or intrahepatic lipid content and only results in mild effects on overnight fasted fat oxidation, postprandial energy expenditure and aortic augmentation index. The lack of marked metabolic effects in this study is associated with a lack of self-reported shivering and a lack of upregulation of gene expression of muscle activation or muscle contraction pathways in skeletal muscle and suggests that some form of muscle contraction is needed for beneficial effects of mild cold acclimation.


Assuntos
Aclimatação/fisiologia , Regulação da Temperatura Corporal/fisiologia , Temperatura Baixa , Diabetes Mellitus Tipo 2/metabolismo , Idoso , Jejum , Feminino , Glucose/metabolismo , Humanos , Resistência à Insulina , Cinética , Metabolismo dos Lipídeos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético , Oxirredução
2.
Nucleic Acids Res ; 49(5): 2460-2487, 2021 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-33550394

RESUMO

Ca2+-insensitive and -sensitive E1 subunits of the 2-oxoglutarate dehydrogenase complex (OGDHC) regulate tissue-specific NADH and ATP supply by mutually exclusive OGDH exons 4a and 4b. Here we show that their splicing is enforced by distant lariat branch points (dBPs) located near the 5' splice site of the intervening intron. dBPs restrict the intron length and prevent transposon insertions, which can introduce or eliminate dBP competitors. The size restriction was imposed by a single dominant dBP in anamniotes that expanded into a conserved constellation of four dBP adenines in amniotes. The amniote clusters exhibit taxon-specific usage of individual dBPs, reflecting accessibility of their extended motifs within a stable RNA hairpin rather than U2 snRNA:dBP base-pairing. The dBP expansion took place in early terrestrial species and was followed by a uridine enrichment of large downstream polypyrimidine tracts in mammals. The dBP-protected megatracts permit reciprocal regulation of exon 4a and 4b by uridine-binding proteins, including TIA-1/TIAR and PUF60, which promote U1 and U2 snRNP recruitment to the 5' splice site and BP, respectively, but do not significantly alter the relative dBP usage. We further show that codons for residues critically contributing to protein binding sites for Ca2+ and other divalent metals confer the exon inclusion order that mirrors the Irving-Williams affinity series, linking the evolution of auxiliary splicing motifs in exons to metallome constraints. Finally, we hypothesize that the dBP-driven selection for Ca2+-dependent ATP provision by E1 facilitated evolution of endothermy by optimizing the aerobic scope in target tissues.


Assuntos
Processamento Alternativo , Regulação da Temperatura Corporal/genética , Íntrons , Complexo Cetoglutarato Desidrogenase/genética , Animais , Cálcio/metabolismo , Evolução Molecular , Éxons , Células HEK293 , Humanos , Sequências Repetitivas Dispersas , Complexo Cetoglutarato Desidrogenase/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Precursores de RNA/química , Precursores de RNA/metabolismo , Sítios de Splice de RNA , Fatores de Processamento de RNA/metabolismo , RNA Mensageiro/química , RNA Mensageiro/metabolismo , Spliceossomos/metabolismo , Vertebrados/genética
3.
Medicine (Baltimore) ; 100(7): e24837, 2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33607852

RESUMO

ABSTRACT: Dysautonomia is common in patients with Parkinson disease (PD) since disease early phase. Scales for Outcomes in Parkinson's disease - Autonomic (SCOPA-AUT) is a well-designed scale assessing the autonomic dysfunctions of PD patients. Our objectives were to examine the autonomic dysfunction in PD and scan without evidence of dopaminergic deficit (SWEDD) patients and to assess the correlation of autonomic dysfunctions with cerebrospinal fluid (CSF) biomarkers.An analysis of the Parkinson's Progression Markers Initiative (PPMI) data including 414 PD patients, 60 SWEDD patients, and 170 healthy controls (HCs) with baseline CSF biomarker measurements and SCOPA-AUT assessments was presented. Autonomic symptoms including gastrointestinal, urinary, cardiovascular, pupillomotor, thermoregulatory and sexual dysfunctions were assessed by SCOPA-AUT scales. Spearman correlation test was used to examine the correlations between CSF measurements and each section of SCOPA-AUT scales in HCs and subjects with PD or SWEDD.More severe autonomic dysfunctions were observed in patients with SWEDD than those with PD (P < .001). Specifically, patients with PD have lower scores on the urinary scale [4 (0-17) vs 5 (1-18)], pupillomotor scale [0 (0-3) vs 0 (0-3)], thermoregulatory scale [0 (0-4) vs 1.5 (0-10)] and sexual scale [1 (0-6) vs 2 (0-6)] compared with SWEDD patients. Thermoregulatory dysfunction scores were found correlated with CSF α-syn levels in SWEDD group, and gastrointestinal dysfunction scores were correlated with CSF Abeta1-42 in PD group. Additionally, urinary dysfunction scores were correlated with CSF total tau and tau phosphorylated at threonine 181(p-tau181) levels in both HCs and PD patients.


Assuntos
Biomarcadores/líquido cefalorraquidiano , Dopamina/deficiência , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/metabolismo , Idoso , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Sistema Nervoso Autônomo/fisiopatologia , Doenças do Sistema Nervoso Autônomo/líquido cefalorraquidiano , Doenças do Sistema Nervoso Autônomo/diagnóstico , Doenças do Sistema Nervoso Autônomo/fisiopatologia , Regulação da Temperatura Corporal/fisiologia , Estudos de Casos e Controles , Feminino , Gastroenteropatias/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/líquido cefalorraquidiano , Doença de Parkinson/fisiopatologia , Disautonomias Primárias/etiologia , Índice de Gravidade de Doença , Inquéritos e Questionários , Doenças Urológicas/metabolismo
4.
Artigo em Inglês | MEDLINE | ID: mdl-33540584

RESUMO

Regular physical activity has multiple health benefits for both the prevention and management of disease, including for older adults. However, additional precautions are needed with ageing given physiological changes and the increasing prevalence of comorbidities. Hot ambient temperatures increase the risks of exercise at any age, but are particularly important given thermoregulatory changes in older people. This narrative review informs planning of physical activity programs for older people living in rural areas with very hot climates for a period of the year. A multi-database search of peer-reviewed literature was undertaken with attention to its relevance to Australia, starting with definitions and standard advice in relation to physical activity programming and the incremental limitations imposed by age, rurality, and extreme heat. The enablers of and barriers to increasing physical activities in older adults and how they can be modified for those living in extreme hot climates is described. We describe multiple considerations in program design to improve safety, adherence and sustaining physical activity, including supervision, simple instructions, provision of reminders, social support, encouraging self-efficacy. Group-based activities may be preferred by some and can accommodate special populations, cultural considerations. Risk management is an important consideration and recommendations are provided to assist program planning.


Assuntos
Regulação da Temperatura Corporal , Exercício Físico , Idoso , Idoso de 80 Anos ou mais , Austrália , Clima , Humanos , Apoio Social
5.
Animal ; 15(1): 100069, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33516012

RESUMO

Thermoregulation is essential to piglets' neonatal survival. This study used infrared thermography (IRT) to assess thermoregulation abilities of piglets from two lines divergent for residual feed intake (RFI). At birth, morphology (weight, length, width and circumference), vigour (respiration, mobility and vocalisation), and rectal temperature were recorded from piglets of the 11th generation of the low RFI (LRFI, more efficient; n = 34) and the high RFI (HRFI, less efficient; n = 28) lines. Infrared thermography images were taken at 8, 15, 30 and 60 min post partum. Temperatures of the ear base and tip, and of the back (i.e. shoulders to rumps) were extracted (Thermacam Researcher Pro 2.0) and analysed with linear mixed models (SAS 9.4). Piglets had different average hourly weight gain (HRFI = 7.1 ±â€¯1.3 g/h, LRFI = 3.6 ±â€¯1.3 g/h; P < 0,001) but did not differ in morphology or vigour. All temperatures increased overtime. At birth, piglets' rectal temperature was correlated with the initial temperature of the ear base and the maximum back temperature (0.37 and 0.33, respectively; P < 0.05). High residual feed intake piglets had lower ear tip temperatures than LRFI piglets at 15 (24.7 ±â€¯0.37 °C vs. 26.3 ±â€¯0.36 °C, respectively; F1, 63.5 = 9.11, P < 0.005) and 30 min post partum (26.2 ±â€¯0.47 °C vs. 27.6 ±â€¯0.44 °C, respectively; F1, 66.9 = 4.52, P < 0.05). Moreover, thermal pattern of the ear tip differed between the two genetic lines. In conclusion, IRT allowed non-invasive assessment of piglets' thermoregulation abilities and indicated an influence of genetic selection for RFI on neonatal thermoregulation abilities.


Assuntos
Regulação da Temperatura Corporal , Ingestão de Alimentos , Ração Animal/análise , Animais , Peso Corporal , Feminino , Recém-Nascido , Parto , Gravidez , Suínos/genética , Ganho de Peso
6.
J Neurol Sci ; 421: 117287, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33445007

RESUMO

We address the impact of the tropical environment on the human nervous system using the multifaceted approach characteristic of environmental neurology. First, environmental factors are examined according to their nature (physical, chemical and biological) and in relation to human activity and behavior. Some factors are specific to the tropics (climate and infections), while others are non-specific (chemicals, human communities and their way of life). Second, we examine the major role of human adaptation to the success of Homo sapiens, with emphasis on the linkage between thermoregulation and sleep-wake regulation. Third, we examine the performance of environmental neurology as a clinical discipline in tropical climates, with focus on the diagnostic and therapeutic challenges posed by human African trypanosomiasis. Finally, the prevention, early detection and monitoring of environmental neurological diseases is examined, as well as links with political and economic factors. In conclusion, practitioners of environmental neurology seek a global, multidisciplinary and holistic approach to understanding, preventing and treating neurological disorders within their purview. Environmental neurology integrates an expanded One Health concept by linking health and wellness to the interaction of plants, animals, humans and the ecosystem. Recent epidemics and the current COVID-19 pandemic exemplify the need for worldwide action to protect human health and biodiversity.


Assuntos
Ecossistema , Exposição Ambiental/efeitos adversos , Medicina Ambiental/tendências , Doenças do Sistema Nervoso/epidemiologia , Neurologia/tendências , Clima Tropical/efeitos adversos , Animais , Regulação da Temperatura Corporal/fisiologia , Medicina Ambiental/métodos , Humanos , Doenças do Sistema Nervoso/terapia , Neurologia/métodos
7.
Behav Processes ; 185: 104317, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33417930

RESUMO

Animals show various forms of behavioral thermoregulation to minimize cold stress. Given that higher dominance rank is often associated with increased fitness in group-living animals, higher-ranking individuals may also benefit from better access to thermally optimal spatial positions within huddles. This study examined the association between dominance rank and the potential thermoregulatory benefits of huddling behavior in Japanese macaques (Macaca fuscata) inhabiting Shodoshima Island, which form exceptionally large huddles. I photographed monkey huddles, and analyzed the number of individuals that males were in contact with and males' spatial positons in huddles. Higher-ranking males were significantly more likely to be in contact with larger numbers of individuals in huddles. Higher-ranking males occupied non-peripheral positions in huddles more often than lower-ranking males, which put them in contact with larger numbers of individuals. These results suggest that high dominance rank may confer potential thermal advantages on male Japanese macaques. The mechanism for this is likely that the highest-ranking male often intrude in already-formed huddles, although such behaviors of males were not quantitatively assessed. This study contributes to a better understanding of the mechanisms of cold adaptation in relation to dominance rank in group-living animals.


Assuntos
Macaca fuscata , Predomínio Social , Animais , Regulação da Temperatura Corporal , Haplorrinos , Macaca , Masculino
9.
Trop Anim Health Prod ; 53(1): 95, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33415443

RESUMO

Chicken is a homeothermic animal; consequently, regardless of fluctuation in weather conditions, it maintains constant body temperature. However, in hot regions and seasons, chickens suffer from heat stress. To dissipate excess heat, besides modifying the environment, which is costly, however, chickens with efficient heat dissipation capacity might be utilized. Naked neck chickens have a higher capacity for heat loss attributable to reduced feather mass. The naked neck mutation (Na) was originated from a large insertion (~ 180 bp) integrated ~ 260-kb downstream of a protein-coding gene-GDF7 (Growth Differentiation Factor 7). Na possesses a cis-regulatory function and upregulates the expression of GDF7-a gene that exhibits a tissue-specific effect by the sensitizing action of retinoic acid. Na suppresses the development of feathers in the neck and vent. Na shows autosomal incomplete dominance and regulates several developmental processes. Na usually segregates at low frequency, which might be attributed to limited socio-cultural preferences. Specifically, in hot and humid regions, although to a varying extent, Na enhances performance, immunocompetence, and resilience to disease both in the homozygous and heterozygous state. Occasionally, naked neck chickens (especially the homozygous ones) lose comparative advantage in cool environments. Homozygous Na also results in high embryo death and reduced hatchability and diminishes floating and flying capacity. Nevertheless, selective breeding of naked neck chickens for fertility traits enhances the performance and welfare of chickens in hot and humid regions. The comparative advantage of Na needs to be studied not only from a temperature perspective and under controlled experiment but also from humidity, body weight, feed intake (absolute and relative to body weight), age, agroecology insights, and under field condition. Due to the incomplete dominant expression pattern of Na, studies need to separately report their findings for homozygous and heterozygous naked neck chicken.


Assuntos
Proteínas Aviárias/genética , Regulação da Temperatura Corporal/fisiologia , Galinhas/fisiologia , Plumas/crescimento & desenvolvimento , Animais , Proteínas Aviárias/metabolismo , Regulação da Temperatura Corporal/genética , Galinhas/genética , Galinhas/crescimento & desenvolvimento , Feminino , Masculino , Mutação
10.
Life Sci ; 265: 118769, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33309717

RESUMO

AIMS: Investigate the role of melatonin on the regulation of body temperature in aged animals that have impaired melatonin production. MATERIAL AND METHODS: Aged Male Wistar rats were randomly assigned to the following groups: 1) control (vehicle added to the water bottles during the dark phase) and 2) melatonin-treated (10 mg/kg melatonin added to the water bottles during the dark phase). Before and after 16 weeks of vehicle or melatonin treatment, control group and melatonin-treated animals were acutely exposed to 18 °C for 2 h for an acute cold challenge and thermal images were obtained using an infrared camera. After 16 weeks, animals were euthanized and brown and beige adipocytes were collected for analysis of genes involved in the thermogenesis process by real-time PCR, and the uncoupling protein expression was evaluated by immunoblotting. Browning intensity of beige adipocytes were quantified by staining with hematoxylin-eosin. KEY FINDINGS: Chronic melatonin supplementation induced a minor increase in body mass and increased the animal's thermogenic potential in the cold acute challenge. Brown and beige adipocytes acted in a coordinated and complementary way to ensure adequate heat production. SIGNIFICANCE: Melatonin plays an important role in the thermoregulatory mechanisms, ensuring greater capacity to withstand cold and, also, participating in the regulation of energy balance.


Assuntos
Regulação da Temperatura Corporal/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Resposta ao Choque Frio/efeitos dos fármacos , Suplementos Nutricionais , Melatonina/farmacologia , Animais , Temperatura Baixa/efeitos adversos , Immunoblotting , Masculino , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real
11.
Enferm. clín. (Ed. impr.) ; 30(6): 377-385, nov.-dic. 2020. tab
Artigo em Espanhol | IBECS | ID: ibc-197667

RESUMO

OBJETIVO: Identificar las medidas de precisión de las características definitorias del diagnóstico de enfermería termorregulación ineficaz en los recién nacidos. MÉTODO: Estudio de precisión diagnóstica de diseño transversal realizado en unidades de maternidad de medio y alto riesgo, localizada en la ciudad de Fortaleza-CE. Se evaluaron 216 recién nacidos para la identificación de las características definitorias del diagnóstico en estudio. Las medidas de precisión de las características definitorias se obtuvieron a partir de un modelo de 2 clases latentes con efectos aleatorios para el cálculo de los valores de sensibilidad y especificidad. RESULTADOS: Las características de frecuencia respiratoria aumentada y piel caliente al tacto presentaron valores de sensibilidad más altos (99,9%) y de especificidades menores (79 y 75%) y las características fluctuaciones de la temperatura corporal por encima y por debajo de los parámetros normales e hipertensión fueron las de mayor especificidad (80,4%) y sensibilidad (100%), respectivamente. CONCLUSIÓN: La característica fluctuación de la temperatura corporal por encima y por debajo de los parámetros normales puede ser más adecuadas para confirmar la presencia del diagnóstico, por haber presentado un mayor valor de especificidad


OBJECTIVE: To identify the measures of accuracy for defining characteristics of the nursing diagnosis: Ineffective thermoregulation in newborns. METHOD: Diagnostic accuracy study with cross-sectional design performed in medium and high-risk maternity units, located in Fortaleza city/Brazil. A total of 216 newborns were evaluated to identify the defining characteristics of the diagnosis under study. The measures of accuracy for defining characteristics were obtained from a latent class model with random effects for the calculation of sensitivity and specificity values. RESULTS: The characteristics of increased respiratory rate and warm skin to the touch had higher sensitivity values (99.9%) and lower specificity (79 and 75%) and the characteristics of body temperature fluctuations above and below the normal parameters and hypertension had the highest specificity (80.4 and 100%, respectively). CONCLUSION: The characteristic fluctuation of the body temperature above and below the normal parameters may be better to confirm the diagnosis, having presented a higher specificity value


Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Diagnóstico de Enfermagem/métodos , Regulação da Temperatura Corporal/fisiologia , Taxa Respiratória , Febre/complicações , Diagnóstico de Enfermagem/normas , Estudos Transversais , Sensibilidade e Especificidade , Encefalopatias/prevenção & controle , Razão de Chances , Febre/diagnóstico , Febre/enfermagem
12.
Apunts, Med. esport (Internet) ; 55(208): 120-127, oct.-dic. 2020. tab, graf, ilus
Artigo em Inglês | IBECS | ID: ibc-197955

RESUMO

INTRODUCTION: Exercise induces modifications in thermal homeostasis. The type of exercise may have a specific impact on skin temperature (Tsk). OBJECTIVE: To analyze and compare the behavior of Tsk in a resistance training between men and women and monitor the thermal recovery response. MATERIAL AND METHODS: Sixteen male and female adults (24.56±3.22 years old) underwent a resistance circuit training session. They performed 3 sets of 12 repetitions with 70-80% 1 RM for lat pulldown, leg press, and biceps arm curl exercises. Thermograms were taken in anterior and posterior body view at rest, 20min, and 24h after training. Tsk was measured in the body regions of interest corresponding to the brachial biceps, quadriceps, and upper back. ANOVA with Tukey's post hoc test was used to analyze Tsk changes among moments, and independent samples t-test was used to compare Tsk between males and females. RESULTS: At rest, women showed Tsk significantly lower than men. There was no significant Tsk change 20min after exercise. However, Tsk increased 24h after exercise in the upper back for men compared with baseline and in quadriceps for women compared with baseline and 20min after exercise (p < 0.05). CONCLUSION: The Tsk of women at rest is lower than that of men. A resistance circuit training session does not significantly change Tsk 20min after exercise, but it increases Tsk 24h after training in the upper back for men and quadriceps for women


No disponible


Assuntos
Humanos , Masculino , Feminino , Adulto , Termografia/instrumentação , Estudo de Prova de Conceito , Resistência Física/efeitos da radiação , Termografia/métodos , Treinamento de Resistência/métodos , Análise de Variância , Regulação da Temperatura Corporal , Músculo Esquelético/efeitos da radiação , Músculo Quadríceps/efeitos da radiação
13.
Acta amaz ; 50(4): 339-345, out. - dez. 2020.
Artigo em Inglês | LILACS | ID: biblio-1146379

RESUMO

Em ectotérmicos, respostas defensivas a predadores geralmente dependem de relações de custo-benefício entre risco de morte e a energia necessária para fugir. Neste estudo, investigamos lagartos na Amazônia para testar a hipótese de que a distância mínima de aproximação de predadores (DAP) é influenciada pela temperatura e camuflagem. Nós testamos a hipótese de que estimativas de DAP para espécies com diferentes modos de termorregulação respondem diferentemente à temperatura e camuflagem. Nós amostramos 35 lagartos de uma espécie heliotérmica e uma não heliotérmica, para as quais simulamos um predador terrestre visualmente orientado. Usando um modelo linear de efeitos fixos, a temperatura afetou positivamente as estimativas de DAP, mas a camuflagem não contribuiu para o modelo. Usando um modelo linear de efeitos mistos, a camuflagem afetou negativamente as estimativas de DAP, independentemente de temperatura. Nossos resultados sugerem que alta exposição a predadores em hábitats abertos pode ser compensada por fuga rápida otimizada por altas temperaturas, e o baixo desempenho de fuga, usualmente causado por temperaturas relativamente mais baixas em habitats sombreados, pode ser compensado pela camuflagem. No entanto, a identificação do melhor preditor de DAP dependeu muito de considerar o modo de termorregulação nos testes de hipóteses, apesar de que os resultados obtidos por ambos os modelos de efeitos fixos e mistos podem ser relevantes para conservação. (AU)


Assuntos
Comportamento , Regulação da Temperatura Corporal , Ecossistema Amazônico , Mimetismo Biológico
14.
Nat Commun ; 11(1): 6378, 2020 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-33311503

RESUMO

Homeotherms maintain a stable internal body temperature despite changing environments. During energy deficiency, some species can cease to defend their body temperature and enter a hypothermic and hypometabolic state known as torpor. Recent advances have revealed the medial preoptic area (MPA) as a key site for the regulation of torpor in mice. The MPA is estrogen-sensitive and estrogens also have potent effects on both temperature and metabolism. Here, we demonstrate that estrogen-sensitive neurons in the MPA can coordinate hypothermia and hypometabolism in mice. Selectively activating estrogen-sensitive MPA neurons was sufficient to drive a coordinated depression of metabolic rate and body temperature similar to torpor, as measured by body temperature, physical activity, indirect calorimetry, heart rate, and brain activity. Inducing torpor with a prolonged fast revealed larger and more variable calcium transients from estrogen-sensitive MPA neurons during bouts of hypothermia. Finally, whereas selective ablation of estrogen-sensitive MPA neurons demonstrated that these neurons are required for the full expression of fasting-induced torpor in both female and male mice, their effects on thermoregulation and torpor bout initiation exhibit differences across sex. Together, these findings suggest a role for estrogen-sensitive MPA neurons in directing the thermoregulatory and metabolic responses to energy deficiency.


Assuntos
Temperatura Corporal/fisiologia , Estrogênios/metabolismo , Neurônios/fisiologia , Área Pré-Óptica/metabolismo , Torpor/fisiologia , Animais , Temperatura Corporal/genética , Regulação da Temperatura Corporal/fisiologia , Metabolismo Energético/fisiologia , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Jejum , Feminino , Hipotermia/genética , Hipotermia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
15.
J Athl Train ; 2020(preprint): 0, 2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33351953

RESUMO

CONTEXT: No research has investigated thermoregulatory responses and exertional heat illness (EHI) risk factors in marching band (MB) artists performing physical activity in high environmental temperatures. OBJECTIVE: Examine core temperature (Tc) and EHI risk factors in MB artists. DESIGN: Descriptive epidemiology study. SETTING: Three rehearsals and 2 football games for 2 NCAA Division I MBs. PARTICIPANTS: Nineteen volunteers completed the study (female = 13, males = 6; age = 20.5 ± 0.9 years; weight = 75.0 ± 19.1 kg; height = 165.1 ± 7.1 cm). MAIN OUTCOME MEASURES: We measured Tc pre-, post-, and every 15 minutes during activity and recorded wet-bulb globe temperature (WBGT) and relative humidity (RH) every 15 minutes. Other variables included activity time and intensity, ground surface, hydration characteristics (fluid volume, sweat rate, urine specific gravity, percent body mass loss [%BM]), and medical history (eg, previous EHI, medications). Statistical analysis included descriptives (mean ± standard deviation), comparative analyses determined differences within and between days, and linear regression identified variables that significantly explained Tc. RESULTS: Mean rehearsal time = 102.8 ± 19.8 minutes and game time = 260.5 ± 47.7 minutes. Max game Tc (39.1 ± 1.1°C) was significantly higher than rehearsal (38.4 ± 0.7°C, P = .003). The highest max game Tc = 41.2°C. Participants consumed significantly more fluid than their sweat rates (P < .003), which minimized %BM loss, particularly during rehearsals (-0.4 ± 0.6%). Mean game %BM loss = -0.9 ± 2.0%; however, 63.6% of the time, participants reported hypohydrated to game day. Max Tc was significantly predicted by max WBGT, max RH, ground surface, using mental health medications, and hours of sleep (adjusted R2 = 0.542, P < .001). CONCLUSIONS: Marching band artists experience high Tc during activity and should have access to athletic trainers who can implement EHI prevention and management strategies.


Assuntos
Temperatura Corporal , Exercício Físico , Regulação da Temperatura Corporal , Aptidão Cardiorrespiratória , Estudos Transversais , Feminino , Futebol Americano , Temperatura Alta , Humanos , Masculino , Música , Prática Psicológica , Fatores de Risco , Sudorese , Universidades , Adulto Jovem
16.
PLoS One ; 15(10): e0237201, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33119606

RESUMO

Temperature varies on a daily and seasonal scale and thermal fluctuations are predicted to become even more pronounced under future climate changes. Studies suggest that plastic responses are crucial for species' ability to cope with thermal stress including variability in temperature, but most often laboratory studies on thermal adaptation in plant and ectotherm organisms are performed at constant temperatures and few species included. Recent studies using fluctuating thermal regimes find that thermal performance is affected by both temperature mean and fluctuations, and that plastic responses likely will differ between species according to life strategy and selective past. Here we investigate how acclimation to fluctuating or constant temperature regimes, but with the same mean temperature, impact on heat stress tolerance across a plant (Arabidopsis thaliana) and two arthropod species (Orchesella cincta and Drosophila melanogaster) inhabiting widely different thermal microhabitats and with varying capability for behavioral stress avoidance. Moreover, we investigate the underlying metabolic responses of acclimation using NMR metabolomics. We find increased heat tolerance for D. melanogaster and A. thaliana exposed to fluctuating acclimation temperatures, but not for O. cincta. The response was most pronounced for A. thaliana, which also showed a stronger metabolome response to thermal fluctuations than both arthropods. Generally, sugars were more abundant across A. thaliana and D. melanogaster when exposed to fluctuating compared to constant temperature, whereas amino acids were less abundant. This pattern was not evident for O. cincta, and generally we do not find much evidence for similar metabolomics responses to fluctuating temperature acclimation across species. Differences between the investigated species' ecology and different ability to behaviorally thermoregulate may have shaped their physiological responses to thermal fluctuations.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Artrópodes/crescimento & desenvolvimento , Regulação da Temperatura Corporal , Drosophila melanogaster/crescimento & desenvolvimento , Resposta ao Choque Térmico , Metaboloma , Animais , Arabidopsis/metabolismo , Artrópodes/metabolismo , Drosophila melanogaster/metabolismo , Masculino
17.
Isr Med Assoc J ; 9(22): 476-480, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32954692

RESUMO

BACKGROUND: Neonatal hypothermia (< 36°C) has been associated with both neonatal morbidity and mortality. OBJECTIVES: To develop a multifactorial approach to reduce the incidence of neonatal hypothermia at admission to the neonatal intensive care unit. METHODS: The approach involved a detailed quality improvement (QI) plan, which included the use of occlusive wrapping and exothermic mattresses as well as higher delivery and operating room environmental temperatures. The improvement plan was implemented over a 10-month period. Retrospective comparison to the same 10-month period during the previous year assessed the effectiveness of the approach in reducing the incidence of admission hypothermia. RESULTS: The QI project included 189 patients. These patients were compared to 180 patients during the control period. The characteristics of the patient groups were similar and included preterm infants, who were subsequently analyzed as a subgroup. We found a significant reduction in the incidence of hypothermia, which was most profound for the subgroup of premature infants born at < 32 weeks gestation. Neonatal hyperthermia was identified as an unintended consequence of the project, and subsequently improved after initiating simple preventive measures. CONCLUSIONS: Occlusive wrapping, exothermic mattresses, and higher delivery and operating room environmental temperature may be successful in reducing admission neonatal hypothermia.


Assuntos
Regulação da Temperatura Corporal/fisiologia , Hipotermia/prevenção & controle , Unidades de Terapia Intensiva Neonatal , Terapia Intensiva Neonatal/métodos , Roupas de Cama, Mesa e Banho , Humanos , Hipotermia/epidemiologia , Incidência , Recém-Nascido , Recém-Nascido Prematuro , Israel , Curativos Oclusivos , Salas Cirúrgicas , Melhoria de Qualidade , Temperatura
18.
Int J Biometeorol ; 64(12): 2185-2194, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32918600

RESUMO

The principal focus of this study was to describe how the coat characteristics could affect the heat exchanges in animals managed in a hot environment. The Morada Nova ewes were monitored once a month, during 10 consecutive months, in three commercial flocks. Initially, an analysis was performed to measure the differences regarding the coat color in the thermoregulation mechanisms. The animals were grouped into 4 different groups according to coat tonality, as follows: dark red animals (group 1, N = 23), intermediate red color (group 2, N = 27), light red animals (group 3, N = 30), and white-coated animals (group 4, N = 30). The data were collected from 1100 to 1400 h, after the animals were exposed to 30 min of direct sunlight. The cluster analysis was performed considering the hair structural characteristics such as coat thickness (CT, cm), hair length (HL, mm), hair diameter (HD, m), and number of hairs (NH, hairs per unit area), after that these clusters were compared in relation to thermoregulatory mechanisms that include rectal temperature (RT, °C), respiratory rate (RR, breaths min-1), cutaneous evaporation (CE, °C), and respiratory evaporation (RE, W m-2). The groups were characterized and compared using mean and standard deviation, and the differences between the clusters were compared using the Tukey test with a 5% probability of error. In relation to coat color, no differences were found in groups 1, 2, and 3 regarding the activation of the thermoregulation mechanisms. The most different was observed in the totally white coat that presented different thermoregulatory responses as the highest sweating rate. White-coated animals showed a non-pigmented epidermis, and the hair structure is responsible to promote skin protection as necessary, such as a dense coat (1242.7 hair cm-2), long hair (14.2 mm), and thicker coat (7.38 mm). In red-coated animals, the hair structure favored heat loss to the environment, such as short hairs, less thick coat, and less hairs per square centimeter. All evaluated animals showed the rectal temperature within the reference limits for the ovine species, regardless of the coat color. In the analysis of clusters related to the physical structure of hair, it was possible to observe that the animals with thick hair, short hair, and less dense coat tended to have a higher capacity to eliminate heat through their respiratory rate and showed less intense heat loss by cutaneous evaporation. We verified that coat color presents a direct influence on the hair structure and the activation of mechanisms related to thermoregulation.


Assuntos
Regulação da Temperatura Corporal , Termotolerância , Animais , Cor , Feminino , Cabelo , Temperatura Alta , Ovinos
19.
Int J Biometeorol ; 64(12): 2161-2169, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32869111

RESUMO

Mountain accident casualties are often exposed to cold and windy weather. This may induce post-traumatic hypothermia which increases mortality. The aim of this study was to assess the ability of warming systems to compensate for the victim's estimated heat loss in a simulated mountain rescue operation. We used thermal manikins and developed a thermodynamic model of a virtual patient. Manikins were placed on a mountain rescue stretcher and exposed to wind chill indices of 0 °C and - 20 °C in a climatic chamber. We calculated the heat balance for two simulated clinical scenarios with both a shivering and non-shivering victim and measured the heat gain from gel, electrical, and chemical warming systems for 3.5 h. The heat balance in the simulated shivering patient was positive. In the non-shivering patient, we found a negative heat balance for both simulated weather conditions (- 429.53 kJ at 0 °C and - 1469.78 kJ at - 20 °C). Each warming system delivered about 300 kJ. The efficacy of the gel and electrical systems was higher within the first hour than later (p < 0.001). We conclude that none of the tested warming systems is able to compensate for heat loss in a simulated model of a non-shivering patient whose physiological heat production is impaired during a prolonged mountain evacuation. Additional thermal insulation seems to be required in these settings.


Assuntos
Hipotermia , Manequins , Temperatura Corporal , Regulação da Temperatura Corporal , Temperatura Baixa , Humanos , Hipotermia/prevenção & controle , Reaquecimento , Tremor por Sensação de Frio
20.
Int J Biometeorol ; 64(12): 2007-2017, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32820392

RESUMO

A new neurophysiological human thermal model based on thermoreceptor responses, the NHTM model, has been developed to predict regulatory responses and physiological variables in asymmetric transient environments. The passive system is based on Wissler's model, which is more complex and refined. Wissler's model segments the human body into 21 cylindrical parts. Each part is divided into 21 layers, 15 for the tissues and 6 for clothes, and each layer is divided into 12 angular sectors. Thus, we have 3780 nodes for the tissues and 1512 for clothes. The passive system simulates heat exchange within the body and between the body and the surroundings. The active system is composed of the thermoregulatory mechanisms, i.e., skin blood flow, shivering thermogenesis, and sweating. The skin blood flow model and the shivering model are based on thermoreceptor responses. The sweating model is that of Fiala et al. and is based on error signals. The NHTM model was compared with Wissler's model, and the results showed that a calculation based on neurophysiology can improve the performance of the thermoregulation model. The NHTM model was more accurate in the prediction of mean skin temperature, with a mean absolute error of 0.27 °C versus 0.80 °C for the original Wissler model. The prediction accuracy of the NHTM model for local skin temperatures and core temperature could be improved via an optimization method to prove the ability of the new thermoregulation model to fit with the physiological characteristics of different populations.


Assuntos
Neurofisiologia , Termorreceptores , Regulação da Temperatura Corporal , Humanos , Temperatura Cutânea , Sudorese
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