Control central de la temperatura corporal y sus alteraciones: fiebre, hipertermia e hipotermia / Central control of body temperature and its alterations: fever, hyperthermia and hypothermia / Controle central da temperatura corporal e suas alterações: febre, hipertermia e hipotermia

Introducción. En mamíferos, el control de la temperatura corporal es vital. El estado de consciencia y control motor en humanos, ocurren a una temperatura de 37°C y las desviaciones pueden alterar las propiedades celulares, generando disfunciones fisiológicas. En especies como los roedores (su relación área de superficie/volumen facilita la pérdida de calor) mantienen temperaturas basales cercanas a los 30°C. Distinto es con animales como los paquidermos, cuya temperatura es menor comparada con los humanos. El objetivo es identificar los aspectos fisiológicos de la termorregulación. Descripción de temas tratados. Revisión descriptiva de la literatura de artículos publicados en diferentes bases de datos. La termorregulación es la capacidad del cuerpo para establecer y mantener su temperatura, regulando producción y pérdida de calor para optimizar la eficiencia de procesos metabólicos. El protagonismo lo tiene el sistema nervioso central y su control neurohormonal en múltiples niveles. El centro regulador térmico está en el hipotálamo anterior. Este recibe información de los receptores de grandes vasos, vísceras abdominales, médula espinal y de la sangre que perfunde el hipotálamo. Cuando aumenta la temperatura central, el termorregulador activa fibras eferentes del sistema nervioso autónomo, provocando pérdida de calor por convección y evaporación. Ante el descenso de temperatura, la respuesta es disminuir la pérdida de calor (vasoconstricción y menor sudoración); además, incrementar la producción de calor, intensificando la actividad muscular. Conclusión. La termorregulación es liderada por el hipotálamo, quien regula aumento y disminución de la temperatura respondiendo a las necesidades del organismo para llegar a la homeostasis y compensación, enfrentando las alteraciones de la temperatura ambiental. Cómo citar: Picón-Jaimes YA, Orozco-Chinome JE, Molina-Franky J, Franky-Rojas MP. Control central de la temperatura corporal y sus alteraciones: fiebre, hipertermia e hipotermia. MedUNAB. 2020;23(1):118-130. doi:10.29375/01237047.3714

Introduction. In mammals, controlling body temperature is vital. Consciousness and motor control in humans occur at a temperature of 37°C and any deviation can alter the cellular properties, generating physiological dysfunctions. In species such as rodents (their surface area/volume ratio facilitates heat loss) they maintain basal temperatures close to 30°C. This is different with animals such as pachyderms, whose temperature is lower compared to humans. This article aims to Identify the physiological aspects of thermoregulation. Topics. Descriptive literature review of articles published in different databases. Thermoregulation is the body's ability to establish and maintain its temperature, regulating heat production and loss to optimize the efficiency of metabolic processes. The main actor in this process is the central nervous system and its neuro-hormonal control on multiple levels. The thermal regulating center is located in the anterior hypothalamus. It receives information from the receptors of large vessels, abdominal viscera, spinal cord and the blood that perfuses the hypothalamus. When the core temperature increases, the thermoregulator activates efferent fibers of the autonomic nervous system, causing heat loss by convection and evaporation. When the temperature drops, the response is to decrease heat loss (vasoconstriction and less sweating); in addition, increase heat production by intensifying muscle activity. Conclusion. Thermoregulation is led by the hypothalamus, which regulates temperature increase and decrease by responding to the organism's need to reach homeostasis and compensation, facing the alterations of the ambient temperature. Cómo citar: Picón-Jaimes YA, Orozco-Chinome JE, Molina-Franky J, Franky-Rojas MP. Control central de la temperatura corporal y sus alteraciones: fiebre, hipertermia e hipotermia. MedUNAB. 2020;23(1):118-130. doi:10.29375/01237047.3714

Introdução. Nos mamíferos, o controle da temperatura corporal é vital. O estado de consciencia e controle motor em humanos ocorre a uma temperatura de 37 °C e os desvios podem alterar as propriedades celulares, gerando disfunções fisiológicas. Espécies como os roedores (a sua relação superfície/volume, facilita a perda de calor), mantêm a temperatura basal próxima de 30 °C. É diferente em animais como paquidermes, cuja temperatura é mais baixa em comparação aos humanos. Objetivo. Identificar os aspectos fisiológicos da termorregulação. Desenvolvimento. Revisão descritiva da literatura de artigos publicados em diferentes bases de dados. A termorregulação é a capacidade do corpo de estabelecer e manter sua temperatura, regulando a produção e a perda de calor para otimizar a eficiência dos processos metabólicos. O sistema nervoso central tem o papel principal, assim como seu controle neuro-hormonal em múltiplos níveis. O centro de regulação térmica está no hipotálamo anterior, que recebe informações dos receptores de grandes vasos, vísceras abdominais, medula espinhal e do sangue distribuído pelo hipotálamo. Quando a temperatura central aumenta, o termorregulador ativa fibras eferentes do sistema nervoso autônomo, causando perda de calor por convecção e evaporação. Dada a diminuição da temperatura, a resposta é reduzir a perda de calor (vasoconstrição e menos transpiração), além de aumentar a produção de calor, intensificando a atividade muscular. Conclusão. A termorregulação é liderada pelo hipotálamo, que regula o aumento e a diminuição da temperatura, respondendo às necessidades do organismo de atingir a homeostase e a compensação, enfrentando mudanças na temperatura ambiente. Cómo citar: Picón-Jaimes YA, Orozco-Chinome JE, Molina-Franky J, Franky-Rojas MP. Control central de la temperatura corporal y sus alteraciones: fiebre, hipertermia e hipotermia. MedUNAB. 2020;23(1):118-130. doi:10.29375/01237047.3714

Antipyretic effect of moxibustion at different temperatures and its relationship with the activity of temperature sensitive neurons in thermotaxic center / 中国针灸

<p><b>OBJECTIVE</b>To discover the central mechanisms of antipyretic effect of moxibustion and its relationship with the acupoint sensor so as to provide the scientific evidence for "the treatment of heat syndrome with moxibustion".</p><p><b>METHODS</b>Eighteen New Zealand Rabbits were randomly assigned into three groups, named group A (modeling with intravenous injection of Endotoxin), group B (moxibustion at 40 degrees C after Endotoxin injection) and group C (moxibustion at 48 degrees C after Endotoxin injection), 6 rabbits in each one. The experiment was undergoing in the condition of muscular relaxation and artificial respiration for the animals. The spotlight moxibustion at constant temperature was applied to "Zhiyang" (GV 9). The discharge of heat sensitive neurons (HSNs) at the preoptic region and anterior hypothalamus (POAH) was taken as the index. The impacts of the treatment on HSNs were observed in each group.</p><p><b>RESULTS AND CONCLUSION</b>Moxibustion had significant antagonism to the pyrogen on its inhibition to the activity of HSNs in the thermotaxic center. As a result, the antipyretic effect was obtained. It is concluded that the effective result of moxibustion is achieved by stimulating polymodal receptors of acupoints.</p>

Transient Receptor Potential (TRP) Channels / 대한이비인후과학회지

Transient receptor potential (TRP) protein is a superfamily of cation channels which have 6 transmembrane domains and mainly pass calcium ion through themselves. There are seven types of subfamilies in the TRP superfamily. TRP channels can be activated by various kinds of stimuli. Some TRP channels are polymodal receptors because two or more types of stimuli can activate the same type of TRP channels. TRP proteins can play roles in a living organism as receptors for sensing outside stimuli or inside local stimuli of itself, as signal conductors, or as signal transducers. Especially, TRP channels have key roles in thermosensation, mechanosensation, taste, trigeminal olfaction and nociception. Therefore, TRP channels can be important subjects of research in ENT field.

Role of thermo TRP channels in cutaneous neurogenic inflammation and itch / 浙江大学学报·医学版

The temperature-sensitive transient receptor potential (TRP) channels, is also called thermo TRP, including TRPV1, TRPV2, TRPV3, TRPV4, TRPM8 and TRPA1, which are expressed in sensory neurons and non-neuronal cells (e.g.keratinocyte, mast cell) of the skin. Thermo TRP channels are activated/sensitized by physical and chemical mediators, which participate in thermosensation and thermoregulation, so that they are key players in pruritus or pain pathogenesis. Thermo TRP channels are also involved in cutaneous neurogenic inflammation, thus they are regarded as molecular targets for future therapy in skin inflammation, pruritus and pain. In addition, following a basic syntax and molecular substrate of nociception and pruriception established by TRP channels-centered concept, the sensory categories can be distinguished and re-defined. Thermo TRP channels should be taken into account when analyzing the pathogenesis and management of itch or pruritic dermatosis.

The terrestrial Gastropoda Megalobulimus abbreviatus as a useful model for nociceptive experiments: effects of morphine and naloxone on thermal avoidance behavior

We describe the behavior of the snail Megalobulimus abbreviatus upon receiving thermal stimuli and the effects of pretreatment with morphine and naloxone on behavior after a thermal stimulus, in order to establish a useful model for nociceptive experiments. Snails submitted to non-functional (22°C) and non-thermal hot-plate stress (30°C) only displayed exploratory behavior. However, the animals submitted to a thermal stimulus (50°C) displayed biphasic avoidance behavior. Latency was measured from the time the animal was placed on the hot plate to the time when the animal lifted the head-foot complex 1 cm from the substrate, indicating aversive thermal behavior. Other animals were pretreated with morphine (5, 10, 20 mg/kg) or naloxone (2.5, 5.0, 7.5 mg/kg) 15 min prior to receiving a thermal stimulus (50°C; N = 9 in each group). The results (means ± SD) showed an extremely significant difference in response latency between the group treated with 20 mg/kg morphine (63.18 ± 14.47 s) and the other experimental groups (P < 0.001). With 2.5 mg/kg (16.26 ± 3.19 s), 5.0 mg/kg (11.53 ± 1.64 s) and 7.5 mg/kg naloxone (7.38 ± 1.6 s), there was a significant, not dose-dependent decrease in latency compared to the control (33.44 ± 8.53 s) and saline groups (29.1 ± 9.91 s). No statistically significant difference was found between the naloxone-treated groups. With naloxone plus morphine, there was a significant decrease in latency when compared to all other groups (minimum 64 percent in the saline group and maximum 83.2 percent decrease in the morphine group). These results provide evidence of the involvement of endogenous opioid peptides in the control of thermal withdrawal behavior in this snail, and reveal a stereotyped and reproducible avoidance behavior for this snail species, which could be studied in other pharmacological and neurophysiological studies.

Efecto de agregado de ácidos y temperatura sobre el desarrollo de listeria monocytogenes / Acids aggregated effect and temperature over listeria monocytogenes development

Listeria monocytogenes es un microorganismos patógeno asociado a enfermedades de origen alimentario que puede crecer y sobrevivir a temperaturas de refrigeración y a pH bajos. Se analiza el efecto de pH 3.0-6.5 dado por diferentes concentraciones de acidulantes (ac. cítrico, ac. láctico, y ac ascórbico) y de la temperatura de refrigeración (4 y 10ºC sobre el desarrollo y supervivencia de listeria monocytogenes en caldo de cultivo triptona soya y extracto de levadura. Se observó disminución de velocidad de desarrollo de l. monocytogenes al disminución la temperatura. El ácido cítrico resultó tener acción antimicrobiana más efectiva manteniendo los recuentos en fase de latencia a baja concentración. El ácido ascórbico fue el menos efectivo ya que la acción bactericida. Se observó a concentraciones muy altas, este junto con el ac. láctico presentaron un efecto inicial en el recuento de microorganismos. La información obtenida fue sintetizada mediante el índice de inhibición (II) y el efecto inhibitiorio (EI).