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1.
Nat Commun ; 12(1): 2648, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33976193

RESUMO

The neural mechanisms of fear-associated thermoregulation remain unclear. Innate fear odor 2-methyl-2-thiazoline (2MT) elicits rapid hypothermia and elevated tail temperature, indicative of vasodilation-induced heat dissipation, in wild-type mice, but not in mice lacking Trpa1-the chemosensor for 2MT. Here we report that Trpa1-/- mice show diminished 2MT-evoked c-fos expression in the posterior subthalamic nucleus (PSTh), external lateral parabrachial subnucleus (PBel) and nucleus of the solitary tract (NTS). Whereas tetanus toxin light chain-mediated inactivation of NTS-projecting PSTh neurons suppress, optogenetic activation of direct PSTh-rostral NTS pathway induces hypothermia and tail vasodilation. Furthermore, selective opto-stimulation of 2MT-activated, PSTh-projecting PBel neurons by capturing activated neuronal ensembles (CANE) causes hypothermia. Conversely, chemogenetic suppression of vGlut2+ neurons in PBel or PSTh, or PSTh-projecting PBel neurons attenuates 2MT-evoked hypothermia and tail vasodilation. These studies identify PSTh as a major thermoregulatory hub that connects PBel to NTS to mediate 2MT-evoked innate fear-associated hypothermia and tail vasodilation.


Assuntos
Medo/fisiologia , Hipotermia/metabolismo , Núcleo Solitário/metabolismo , Núcleo Subtalâmico/metabolismo , Canal de Cátion TRPA1/metabolismo , Animais , Regulação da Temperatura Corporal/fisiologia , Medo/psicologia , Hipotermia/induzido quimicamente , Hipotermia/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/metabolismo , Optogenética/métodos , Proteínas Proto-Oncogênicas c-fos/metabolismo , Canal de Cátion TRPA1/genética , Tiazóis , Vasodilatação/fisiologia
2.
Aging (Albany NY) ; 13(7): 10087-10098, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33818420

RESUMO

Hypothalamic nuclei in the preoptic and anterior hypothalamic region (POAH) are critically involved in thermoregulation and neuroendocrine regulation and can be displaced by craniopharyngiomas (CPs). We aimed to locate the POAH by visualizing hypothalamic thermoregulation through task-related functional magnetic resonance imaging (fMRI) to guide hypothalamus protection intraoperatively. Nine adult healthy volunteers (HVs) and thirty-two adult primary CP patients underwent task-related fMRI for POAH localization by warm (60° C) and cold (0° C) cutaneous thermoreceptor stimulation. Approach selection and intraoperative POAH protection were performed based on preoperative POAH localization. In all HVs and patients, significant single positive blood oxygen level-dependent (BOLD) signal changes were located in the POAH. The BOLD activity was significantly greater for cold (P=0.03) and warm (P=0.03) stimuli in patients than in HVs. Gross total resection and near-total resection were achieved in 28 (87.5%) and 4 (12.5%) patients, respectively. New-onset diabetes insipidus and new-onset hypopituitarism occurred in 6 patients (18.8%) and 10 patients (31.3%), respectively. Our findings suggest that cutaneous thermoreceptor stimulation could accurately activate the hypothalamic thermoregulatory center and allow POAH localization through task-related fMRI. Preoperative POAH localization could help neurosurgeons protect hypothalamic function intraoperatively. The CP patients were more sensitive to thermal stimulation.


Assuntos
Núcleo Hipotalâmico Anterior/diagnóstico por imagem , Regulação da Temperatura Corporal/fisiologia , Craniofaringioma/diagnóstico por imagem , Neoplasias Hipofisárias/diagnóstico por imagem , Área Pré-Óptica/diagnóstico por imagem , Adulto , Temperatura Baixa , Feminino , Temperatura Alta , Humanos , Imageamento por Ressonância Magnética , Masculino , Neurônios/fisiologia
3.
Nat Metab ; 3(4): 485-495, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33846638

RESUMO

Brown adipose tissue (BAT) and beige fat function in energy expenditure in part due to their role in thermoregulation, making these tissues attractive targets for treating obesity and metabolic disorders. While prolonged cold exposure promotes de novo recruitment of brown adipocytes, the exact sources of cold-induced thermogenic adipocytes are not completely understood. Here, we identify transient receptor potential cation channel subfamily V member 1 (Trpv1)+ vascular smooth muscle (VSM) cells as previously unidentified thermogenic adipocyte progenitors. Single-cell RNA sequencing analysis of interscapular brown adipose depots reveals, in addition to the previously known platelet-derived growth factor receptor (Pdgfr)α-expressing mesenchymal progenitors, a population of VSM-derived adipocyte progenitor cells (VSM-APC) expressing the temperature-sensitive cation channel Trpv1. We demonstrate that cold exposure induces the proliferation of Trpv1+ VSM-APCs and enahnces their differentiation to highly thermogenic adipocytes. Together, these findings illustrate the landscape of the thermogenic adipose niche at single-cell resolution and identify a new cellular origin for the development of brown and beige adipocytes.


Assuntos
Adipócitos/fisiologia , Temperatura Baixa , Células-Tronco Hematopoéticas/fisiologia , Músculo Liso Vascular/fisiologia , Canais de Cátion TRPV/fisiologia , Termogênese/fisiologia , Adipócitos Bege/fisiologia , Adipócitos Marrons/fisiologia , Tecido Adiposo Bege/metabolismo , Tecido Adiposo Marrom/fisiologia , Animais , Regulação da Temperatura Corporal/fisiologia , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Humanos , Células-Tronco Mesenquimais , Camundongos , Camundongos Endogâmicos C57BL , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Canais de Cátion TRPV/genética
4.
J Sports Sci Med ; 20(1): 26-34, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33707983

RESUMO

We investigated whether single or combined methods of pre-cooling could affect high-intensity exercise performance in a hot environment. Seven male athletes were subjected to four experimental conditions for 30 min in a randomised order. The four experimental conditions were: 1) wearing a vest cooled to a temperature of 4 ℃ (Vest), 2) consuming a beverage cooled to a temperature of 4 ℃ (Beverage), 3) simultaneous usage of vest and consumption of beverage (Mix), and 4) the control trial without pre-cooling (CON). Following those experimental conditions, they exercised at a speed of 80% VO2max until exhaustion in the heat (38.1 ± 0.6 ℃, 55.3 ± 0.3% RH). Heart rate (HR), rectal temperature (Tcore), skin temperature (Tskin), sweat loss (SL), urine specific gravity (USG), levels of sodium (Na+) and potassium (K+), rating of perceived exertion (RPE), thermal sensation (TS), and levels of blood lactic acid ([Bla]) were monitored. Performance was improved using the mixed pre-cooling strategy (648.43 ± 77.53 s, p = 0.016) compared to CON (509.14 ± 54.57 s). Tcore after pre-cooling was not different (Mix: 37.01 ± 0.27 ℃, Vest: 37.19 ± 0.33 ℃, Beverage: 37.03 ± 0.35 ℃) in all cooling conditions compared to those of CON (37.31 ±0.29 ℃). A similar Tcore values was achieved at exhaustion in all trials (from 38.10 ℃ to 39.00 ℃). No difference in the level of USG was observed between the conditions. Our findings suggest that pre-cooling with a combination of cold vest usage and cold fluid intake can improve performance in the heat.


Assuntos
Desempenho Atlético/fisiologia , Crioterapia/métodos , Temperatura Alta , Corrida/fisiologia , Bebidas , Regulação da Temperatura Corporal/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Consumo de Oxigênio , Esforço Físico/fisiologia , Potássio/urina , Distribuição Aleatória , Reto/fisiologia , Sensação , Temperatura Cutânea/fisiologia , Sódio/urina , Gravidade Específica , Sudorese/fisiologia , Fatores de Tempo , Urina/química , Adulto Jovem
5.
Nat Commun ; 12(1): 1823, 2021 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-33758197

RESUMO

The body naturally and continuously secretes sweat for thermoregulation during sedentary and routine activities at rates that can reflect underlying health conditions, including nerve damage, autonomic and metabolic disorders, and chronic stress. However, low secretion rates and evaporation pose challenges for collecting resting thermoregulatory sweat for non-invasive analysis of body physiology. Here we present wearable patches for continuous sweat monitoring at rest, using microfluidics to combat evaporation and enable selective monitoring of secretion rate. We integrate hydrophilic fillers for rapid sweat uptake into the sensing channel, reducing required sweat accumulation time towards real-time measurement. Along with sweat rate sensors, we integrate electrochemical sensors for pH, Cl-, and levodopa monitoring. We demonstrate patch functionality for dynamic sweat analysis related to routine activities, stress events, hypoglycemia-induced sweating, and Parkinson's disease. By enabling sweat analysis compatible with sedentary, routine, and daily activities, these patches enable continuous, autonomous monitoring of body physiology at rest.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Regulação da Temperatura Corporal/fisiologia , Microfluídica/métodos , Suor/metabolismo , Sudorese/fisiologia , Dispositivos Eletrônicos Vestíveis , Corpo Humano , Humanos , Concentração de Íons de Hidrogênio , Hipoglicemia/metabolismo , Levodopa/metabolismo , Microfluídica/instrumentação , Doença de Parkinson/metabolismo , Descanso/fisiologia , Estresse Fisiológico/fisiologia , Suor/fisiologia , Caminhada/fisiologia
6.
Am J Physiol Regul Integr Comp Physiol ; 320(6): R780-R790, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33787332

RESUMO

The current study investigated whether ambient heat augments the inflammatory and postexercise hepcidin response in women and if menstrual phase and/or self-pacing modulate these physiological effects. Eight trained females (age: 37 ± 7 yr; V̇o2max: 46 ± 7 mL·kg-1·min-1; peak power output: 4.5 ± 0.8 W·kg-1) underwent 20 min of fixed-intensity cycling (100 W and 125 W) followed by a 30-min work trial (∼75% V̇o2max) in a moderate (MOD: 20 ± 1°C, 53 ± 8% relative humidity) and warm-humid (WARM: 32 ± 0°C, 75 ± 3% relative humidity) environment in both their early follicular (days 5 ± 2) and midluteal (days 21 ± 3) phases. Mean power output was 5 ± 4 W higher in MOD than in WARM (P = 0.02) such that the difference in core temperature rise was limited between environments (-0.29 ± 0.18°C in MOD, P < 0.01). IL-6 and hepcidin both increased postexercise (198% and 38%, respectively); however, neither was affected by ambient temperature or menstrual phase (all P > 0.15). Multiple regression analysis demonstrated that the IL-6 response to exercise was explained by leukocyte and platelet count (r2 = 0.72, P < 0.01), and the hepcidin response to exercise was explained by serum iron and ferritin (r2 = 0.62, P < 0.01). During exercise, participants almost matched their fluid loss (0.48 ± 0.18 kg·h-1) with water intake (0.35 ± 0.15 L·h-1) such that changes in body mass (-0.3 ± 0.3%) and serum osmolality (0.5 ± 2.0 osmol·kgH2O-1) were minimal or negligible, indicating a behavioral fluid-regulatory response. These results indicate that trained, iron-sufficient women suffer no detriment to their iron regulation in response to exercise with acute ambient heat stress or between menstrual phases on account of a performance-physiological trade-off.


Assuntos
Regulação da Temperatura Corporal/fisiologia , Exercício Físico/fisiologia , Ciclo Menstrual/fisiologia , Temperatura , Adulto , Temperatura Corporal/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Transtornos de Estresse por Calor/fisiopatologia , Resposta ao Choque Térmico/fisiologia , Humanos
7.
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
8.
Public Health ; 193: 1-9, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33662760

RESUMO

OBJECTIVES: The elderly are the most at-risk population for heat-related illness and mortality during the periods of hot weather. However, evidence-based elderly-specific cooling strategies to prevent heat-illness are limited. The aim of this investigation was to quantify the elderly's physiological and perceptual responses to cooling through cold water ingestion (COLD) or an L-menthol mouth rinse (MENT) during simulated activities of daily living in UK summer climatic conditions. STUDY DESIGN: Randomised, controlled repeated measures research design. METHODS: A total of ten participants (men n = 7, women n = 3: age; 69 ± 3 yrs, height; 168 ± 10 cm, body mass; 68.88 ± 13.72 kg) completed one preliminary and three experimental trials; control (CON), COLD and MENT. Experimental trials consisted of 40 min rest followed by 30 min of cycling exercise at 6 metabolic equivalents and a 6-min walk test (6MWT), within a 35 °C, 50% relative humidity environment. Experimental interventions (every 10 min); cold water (4 °C) ingestion (total of 1.5L) or menthol (5 ml mouth swill for 5 s, menthol concentration of 0.01%). RESULTS: Peak rectal temperature (Tre) was significantly (P < 0.05) lower in COLD compared with CON (-0.34 ± 0.16 °C) and MENT (-0.36 ± 0.20 °C). End exercise heart rate (HR) decreased in COLD compared with CON (-7 ± 9 b min-1) and MENT (-6 ± 7 b min-1). There was no difference in end exercise thermal sensation (TS) (CON; 6.1 ± 0.4, COLD; 6.0 ± 0.4, MENT; 6.4 ± 0.6) or thermal comfort (TC) (CON; 4 ± 1, COLD; 4 ± 1, MENT; 4 ± 1) between trials. The participants walked significantly further during the COLD 6MWT compared with CON (40 m ± 40 m) and MENT (40 m ± 30 m). There was reduced physiological strain in the COLD 6MWT compared with CON (Tre; -0.21 ± 0.24 °C, HR; -7 ± 8 b min-1) and MENT (Tre; -0.23 ± 0.24 °C, HR; -4 ± 7 b min-1). CONCLUSION: The elderly have reduced physiological strain (Tre and HR) during activities of daily living and a 6MWT in hot UK climatic conditions, when they drink cold water. Furthermore, the elderly's perception (TS and TC) of the hot environment did not differ from CON at the end of exercise with COLD or MENT interventions. Menthol provided neither perceptual benefit to exercise in the heat nor functional gain. The TS data indicate that elderly may be at increased risk of heat illness, due to not feeling hot and uncomfortable enough to implement physiological strain reducing strategies such as cold-water ingestion.


Assuntos
Atividades Cotidianas/psicologia , Regulação da Temperatura Corporal/fisiologia , Exercício Físico/fisiologia , Transtornos de Estresse por Calor/prevenção & controle , Temperatura Alta/efeitos adversos , Idoso , Feminino , Humanos , Masculino , Estações do Ano , Reino Unido
9.
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
10.
Artigo em Inglês | MEDLINE | ID: mdl-33609807

RESUMO

The interpretation of thermal-gradient data depends on the behavioral drives reported or assumed, and on the underlying behavioral models explaining how such drives operate. The best-known example is positive thermotaxis, a thermoregulatory behavioral drive frequently linked to a dual set-point model of thermoregulation around a target range. This behavioral drive is often assumed as dominant among 'ectotherms', including amphibians. However, we argue that, because amphibians are extremely diverse, they may exhibit alternative behavioral drives in thermal gradients, and tackle this idea from two perspectives. First, we provide a historical review of original definitions and proposed limits for inference. Second, although caveats apply, we propose that a cross-study analysis of data of temperature settings of gradients and the temperatures selected by amphibians would corroborate alternative behavioral drives, including negative thermotaxis. Therefore, we analyzed published data focusing on such relationships and show that gradient temperature settings influence the temperatures selected by amphibians, with further effects of phylogeny and ontogeny. We conclude that thermal gradient experiments are outstanding tools to investigate behavioral drives, but no given drive can be assumed a priori unless additional information about thermoregulation is available. Based on the historical debate, we propose using selected temperatures and preferred temperatures as different concepts, the former merely operational and the second explicitly linked to positive thermotaxis (and thus compatible with dual set-point thermoregulation). Under this view, thermal preferences would stand for a hypothesis of a behavioral drive (positive thermotaxis) requiring formal testing. These considerations impact the scope for inference based on thermal gradient experiments, particularly ecological modeling and emerging disease.


Assuntos
Anfíbios/fisiologia , Regulação da Temperatura Corporal/fisiologia , Animais , Temperatura
11.
Enferm. glob ; 20(61): 59-71, ene. 2021. tab
Artigo em Espanhol | IBECS | ID: ibc-201455

RESUMO

OBJETIVO: Analizar el patrón de temperatura de recién nacidos de bajo peso al nacer ingresados en una Unidad de Cuidados Intensivos Neonatales. METODOLOGÍA: Este es un estudio transversal y cuantitativo realizado en una Unidad de Cuidados Intensivos Neonatales en un hospital de maternidad en el noreste de Brasil. La muestra consistió en 45 niños de bajo peso al nacer, muy bajo peso al nacer o extremadamente bajo peso al nacer ingresados ​​en la unidad. RESULTADOS: Al ingreso se obtuvo una temperatura axilar promedio de 34.98ºC con una desviación estándar de 1.12. La tasa de hipotermia al ingreso fue considerablemente severa, por lo que en la primera hora, con seis horas y con 12 horas de hospitalización, el porcentaje de recién nacidos hipotérmicos (<36.5ºC) fue respectivamente: 93.33%, 73.33 % y 57.78%. CONCLUSIÓN: Hubo fallas en los procesos cuando se trata de termorregulación, dado que casi toda la muestra llega con potencial estrés por frío


OBJETIVO: Analisar o padrão de temperatura dos recém-nascidos de baixo peso internados em uma Unidade de Terapia Intensiva Neonatal. METODOLOGIA: Trata-se de um estudo transversal e quantitativo realizado numa Unidade de Terapia Intensiva Neonatal de uma maternidade no Nordeste do Brasil. A amostra foi constituída de 45 recém-nascidos de baixo peso, muito baixo peso ou extremo baixo peso admitidos na unidade. RESULTADOS: Na admissão obteve-se uma média de temperatura axilar de 34,98ºC com desvio padrão de 1,12. A taxa de hipotermia na admissão foi consideravelmente grave, de forma que na primeira hora, com seis horas e com 12 horas de internação a porcentagem de recém-nascidos hipotérmicos (<36,5ºC) foi respectivamente: 93,33%, 73,33% e 57,78%. CONCLUSÃO: Verificou-se falhas nos processos quando se trata de termorregulação, haja vista que quase a totalidade da amostra chega com potencial estresse ao frio


OBJECTIVE: To analyze the temperature pattern of low birth weight newborns admitted to a Neonatal Intensive Care Unit METHODOLOGY: This is a cross-sectional and quantitative study conducted in a Neonatal Intensive Care Unit of a maternity hospital in Northeastern Brazil. The sample consisted of 45 low birth weight, very low birth weight or extremely low birth weight newborns admitted to the unit. RESULTS: At admission, we obtained an axillary temperature average of 34.98ºC with a standard deviation of 1.12. The hypothermia rate at the time of admission was considerably severe, so that in the first hour, with 06 hours and with 12 hours of hospitalization, the percentages of hypothermic newborns (<36.5ºC) were respectively: 93.33%, 73.33 % and 57.78%. CONCLUSION: We found flaws in the processes when it comes to thermoregulation, given that almost the entire sample arrives with potential cold stress


Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Terapia Intensiva Neonatal/métodos , Hipotermia/enfermagem , Regulação da Temperatura Corporal/fisiologia , Resposta ao Choque Frio , Unidades de Terapia Intensiva Neonatal/estatística & dados numéricos , Resultados de Cuidados Críticos , Recém-Nascido de muito Baixo Peso/fisiologia , Fatores de Risco , Estudos Transversais , Lesão por Frio/epidemiologia
12.
Enferm. glob ; 20(61): 464-475, ene. 2021. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-201470

RESUMO

OBJETIVOS: El objetivo es describir los métodos de calentamiento y su aplicación para el mantenimiento de la temperatura corporal en el paciente gran quemado. METODOLOGÍA: Revisión bibliográfica realizada entre septiembre de 2019 y febrero de 2020 acerca de la termorregulación y calentamiento del paciente quemado en las bases de datos CINAHL, CUIDEN, PUBMED, MEDES y WOS en español e inglés, de los últimos 10 años, de los cuales fueron analizados 24 documentos. RESULTADOS: La respuesta hipermetabólica y la reprogramación hipotalámica provocan un aumento de la temperatura basal en los pacientes quemados, entre 37 y 38,5ºC sin origen infeccioso. Para disminuir el gasto energético en reposo y la repuesta hipermetabólica se puede aplicar una temperatura ambiental elevada, como calentamiento externo pasivo, entre 28 y 32ºC. DISCUSIÓN: Existen otros métodos de calentamiento externo activo que pueden conseguir el mismo objetivo como las mantas de aire convectivo, placas térmicas o sistemas de superficie. CONCLUSIÓN: Debe revisarse la recomendación de calentamiento mediante temperatura ambiental elevada, que crea ambientes hostiles para los trabajadores y los pacientes, a través del estudio de la inclusión de métodos de calentamiento externo activo


OBJECTIVES: To describe the heating methods and their application to maintain body temperature in majors burn patients. METHODOLOGY: Bibliographic review carried out between September 2019 and February 2020 about the thermoregulation and heating of the burn patient in the CINHAL, CUIDEN, PUBMED, MEDES and WOS databases in Spanish and English, documents from the last 10 years, from which 26 were analyzed. RESULTS: Hypermetabolic response and hypothalamic reprogramming cause an increase in basal temperature in burn patients between 37 and 38.5ºC without infectious origin. To decrease the energy expenditure at rest and the hypermetabolic response, it is possible to act through a high ambient temperature between 28 and 32ºC as passive external heating. DISCUSSION: Other external heating methods can achieve this goal such as convective air blankets, heating plates, or surface systems. CONCLUSIONS: The recommendation of warming by means of high ambient temperature, which creates hostile environments for workers and patients, should be reviewed through the study of the inclusion of active external warming methods


Assuntos
Humanos , Queimaduras/terapia , Temperatura Corporal/fisiologia , Regulação da Temperatura Corporal/fisiologia , Metabolismo Energético/fisiologia , Queimaduras/enfermagem , Hipertermia Induzida/enfermagem
14.
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
15.
PLoS One ; 16(1): e0244458, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33406524

RESUMO

Behavioral thermoregulation is an important defense against the negative impacts of climate change for ectotherms. In this study we examined the use of burrows by a common intertidal crab, Minuca pugnax, to control body temperature. To understand how body temperatures respond to changes in the surface temperature and explore how efficiently crabs exploit the cooling potential of burrows to thermoregulate, we measured body, surface, and burrow temperatures during low tide on Sapelo Island, GA in March, May, August, and September of 2019. We found that an increase in 1°C in the surface temperature led to a 0.70-0.71°C increase in body temperature for females and an increase in 0.75-0.77°C in body temperature for males. Body temperatures of small females were 0.3°C warmer than large females for the same surface temperature. Female crabs used burrows more efficiently for thermoregulation compared to the males. Specifically, an increase of 1°C in the cooling capacity (the difference between the burrow temperature and the surface temperature) led to an increase of 0.42-0.50°C for females and 0.34-0.35°C for males in the thermoregulation capacity (the difference between body temperature and surface temperature). The body temperature that crabs began to use burrows to thermoregulate was estimated to be around 24°C, which is far below the critical body temperatures that could lead to death. Many crabs experience body temperatures of 24°C early in the reproductive season, several months before the hottest days of the year. Because the use of burrows involves fitness trade-offs, these results suggest that warming temperatures could begin to impact crabs far earlier in the year than expected.


Assuntos
Regulação da Temperatura Corporal/fisiologia , Braquiúros/fisiologia , Animais , Comportamento Animal , Temperatura Corporal , Braquiúros/crescimento & desenvolvimento , Ecossistema , Feminino , Masculino , Reprodução , Estações do Ano
16.
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
17.
J Sports Med Phys Fitness ; 61(1): 18-26, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32936567

RESUMO

BACKGROUND: The effects of a reduced or mildly elevated exercising muscle temperature on the graded exercise test (GXT) performance have yet to be studied. The present study clarified the effects of a range of exercising muscle temperatures on GXT performance in a temperate environment. METHODS: Eight male subjects (age: 24.0±0.5 years old; height: 175±2 cm; weight: 64.8±2.0 kg; peak oxygen consumption [V̇O2peak]: 51.1±2.4 mL/kg/min) performed 4 GXTs at different exercising muscle temperatures using a cycle-ergometer in a temperate environment (24.1±0.2 °C). The exercise began at 0.3 kilopond (kp) with 60 revolutions per minute (rpm) and increased 0.3 kp every minute until volitional exhaustion. Subjects passively cooled (averaged deep thigh and calf temperature [Tmm], cold: 31 °C or cool: 33 °C) or warmed (Tmm; warm: 35 °C or hot: 37 °C) the exercising muscle using water perfusion pants throughout the test. The peak oxygen consumption (V̇O2peak), exercise time to exhaustion (TTE), heart rate (HR), tympanic (Tty) and mean body temperature (Tb), and total sweat loss were also measured. RESULTS: No significant differences were observed in the V̇O2peak or TTE among the 4 conditions; however, the HR, Tb, and total sweat loss were significantly higher (P<0.05) under warming conditions than cooling conditions. CONCLUSIONS: These results suggest that although the cardiovascular and thermoregulatory strain is higher under warming conditions than cooling conditions, the exercising muscle temperature does not affect the performance of a GXT lasting approximately 15 min in a temperate environment.


Assuntos
Exercício Físico/fisiologia , Adulto , Desempenho Atlético/fisiologia , Temperatura Corporal/fisiologia , Regulação da Temperatura Corporal/fisiologia , Temperatura Baixa , Teste de Esforço , Frequência Cardíaca/fisiologia , Humanos , Perna (Membro) , Masculino , Sudorese , Temperatura , Coxa da Perna/fisiologia , Adulto Jovem
18.
Scand J Med Sci Sports ; 31(1): 4-20, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32969103

RESUMO

Handcycling is a mode of mobility, and sport format within Para-cycling, for those with a lower limb impairment. The exercise modality has been researched extensively in the rehabilitation setting. However, there is an emerging body of evidence detailing the physiological responses to handcycling in the competitive sport domain. Competitive handcyclists utilize equipment that is vastly disparate to that used for rehabilitation or recreation. Furthermore, the transferability of findings from early handcycling research to current international athletes regarding physiological profiles is severely limited. This narrative review aims to map the landscape within handcycling research and document the growing interest at the elite end of the exercise spectrum. From 58 experimental/case studies and four doctoral theses, we provide accounts of the aerobic capacity of handcyclists and the influence training status plays; present research regarding the physiological responses to handcycling performance, including tests of sprint performance; and discuss the finite information on handcyclists' training habits and efficacy of bespoke interventions. Furthermore, given the wide variety of protocols employed and participants recruited previously, we present considerations for the interpretation of existing research and recommendations for future work, all with a focus on competitive sport. The majority of studies (n = 21) reported aerobic capacity, detailing peak rates of oxygen uptake and power output, with values >3.0 L min-1 and 240 W shown in trained, male H3-H4 classification athletes. Knowledge, though, is lacking for other classifications and female athletes. Similarly, little research is available concerning sprint performance with only one from eight studies recruiting athletes with an impairment.


Assuntos
Ciclismo/fisiologia , Comportamento Competitivo/fisiologia , Esportes para Pessoas com Deficiência/fisiologia , Desempenho Atlético/fisiologia , Regulação da Temperatura Corporal/fisiologia , Suplementos Nutricionais , Teste de Esforço , Humanos , Músculo Esquelético/fisiologia , Consumo de Oxigênio , Condicionamento Físico Humano/fisiologia , Equipamentos Esportivos
19.
J Exp Zool A Ecol Integr Physiol ; 335(1): 173-194, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32970931

RESUMO

Ectothermic animals, such as amphibians and reptiles, are particularly sensitive to rapidly warming global temperatures. One response in these organisms may be to evolve aspects of their thermal physiology. If this response is adaptive and can occur on the appropriate time scale, it may facilitate population or species persistence in the changed environments. However, thermal physiological traits have classically been thought to evolve too slowly to keep pace with environmental change in longer-lived vertebrates. Even as empirical work of the mid-20th century offers mixed support for conservatism in thermal physiological traits, the generalization of low evolutionary potential in thermal traits is commonly invoked. Here, we revisit this hypothesis to better understand the mechanisms guiding the timing and patterns of physiological evolution. Characterizing the potential interactions among evolution, plasticity, behavior, and ontogenetic shifts in thermal physiology is critical for accurate prediction of how organisms will respond to our rapidly warming world. Recent work provides evidence that thermal physiological traits are not as evolutionarily rigid as once believed, with many examples of divergence in several aspects of thermal physiology at multiple phylogenetic scales. However, slow rates of evolution are often still observed, particularly at the warm end of the thermal performance curve. Furthermore, the context-specificity of many responses makes broad generalizations about the potential evolvability of traits tenuous. We outline potential factors and considerations that require closer scrutiny to understand and predict reptile and amphibian evolutionary responses to climate change, particularly regarding the underlying genetic architecture facilitating or limiting thermal evolution.


Assuntos
Adaptação Fisiológica , Anfíbios/fisiologia , Regulação da Temperatura Corporal/fisiologia , Répteis/fisiologia , Animais
20.
Integr Zool ; 16(1): 53-66, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32822078

RESUMO

Behavioral and physiological traits of ectotherms are especially sensitive to fluctuations of environmental temperature. In particular, niche-specialist lizards are dependent on their physiological plasticity to adjust to changing environmental conditions. Lizards of the genus Phymaturus are viviparous, mainly herbivorous, and inhabit only rock promontories in the steppe environments of Patagonia and the Andes. Herein, we examine the vulnerability of the southernmost Phymaturus species to global warming: the endemic Phymaturus calcogaster, which lives in a mesic environment in eastern Patagonia. We studied body temperatures in the field (Tb ), preferred body temperatures in a thermogradient (Tpref ), the operative (Te ) and environmental temperatures, and the dependence of running performance on body temperature. P. calcogaster had a mean Tb (27.04°C) and a mean Te (31.15°C) both lower than their preferred temperature (Tpref = 36.61°C) and the optimal temperature for running performance (To = 37.13°C). Lizard activity seems to be restraint during the early afternoon due high environmental temperatures. However, both, the high safety margin and warming tolerance suggest that the expected increase in environmental temperatures due to global warming (IPCC report in 2018) would not threaten, but indeed enhance locomotor performance in this population.


Assuntos
Regulação da Temperatura Corporal/fisiologia , Lagartos/fisiologia , Locomoção/fisiologia , Animais , Argentina , Temperatura Corporal/fisiologia , Mudança Climática , Feminino , Masculino , Temperatura
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