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1. Influence of limb temperature on cutaneous silent periods.

Author

Kofler M, Valls-Solé J, Vasko P, Boček V, and Štetkárová I

Subjects
Action Potentials physiology, Adult, Female, Humans, Male, Median Nerve physiology, Middle Aged, Motor Neurons physiology, Nerve Fibers, Myelinated physiology, Neural Conduction physiology, Sensory Receptor Cells physiology, Sensory Thresholds physiology, Temperature, Young Adult, Body Temperature physiology, Extremities physiology, Reflex physiology, Skin innervation
Abstract

Objective: The cutaneous silent period (CSP) is a spinal inhibitory reflex mediated by small-diameter afferents (A-delta fibers) and large-diameter efferents (alpha motoneurons). The effect of limb temperature on CSPs has so far not been assessed., Methods: In 27 healthy volunteers (11 males; age 22-58 years) we recorded median nerve motor and sensory action potentials, median nerve F-wave and CSPs induced by noxious digit II stimulation in thenar muscles in a baseline condition at room temperature, and after randomly submersing the forearm in 42 °C warm or 15 °C cold water for 20 min each., Results: In cold limbs, distal and proximal motor and sensory latencies as well as F-wave latencies were prolonged. Motor and sensory nerve conduction velocities were reduced. Compound motor and sensory nerve action potential amplitudes did not differ significantly from baseline. CSP onset and end latencies were more delayed than distal and proximal median nerve motor and sensory latencies, whereas CSP duration was not affected. In warm limbs, opposite but smaller changes were seen in nerve conduction studies and CSPs., Conclusion: The observed CSP shift "en bloc" towards longer latencies without affecting CSP duration during limb cooling concurs with slower conduction velocity in both afferent and efferent fibers. Disparate conduction slowing in afferents and efferents, however, suggests that nociceptive EMG suppression is mediated by fibers of different size in the afferent than in the efferent arm, indirectly supporting the contribution of A-delta fibers as the main afferent input., Significance: Limb temperature should be taken into account when testing CSPs in the clinical setting, as different limb temperatures affect CSP latencies more than large-diameter fiber conduction function., (Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Published
2014
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9. STUDY OF SKIN TEMPERATURES.

Author

MALIN HV

Subjects
Humans, Body Temperature, Physiology, Rectum, Research, Skin, Skin Temperature
Published
1964

10. ELEVATION OF BODY TEMPERATURE IN HEALTH.

Author

MINARD D, COPMAN L, and DASLER AR

Subjects
Humans, Body Temperature, Body Temperature Regulation, Esophagus, Hot Temperature, Physical Exertion, Physiology, Rectum, Skin, Tympanic Membrane
Published
1964
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11. SYSTEMIC CHANGES DURING THE MENSTRUAL CYCLE.

Author

SOUTHAM AL and GONZAGA FP

Subjects
Female, Humans, Behavior, Blood Cell Count, Blood Pressure, Blood Pressure Determination, Body Temperature, Body Weight, Bone and Bones, Breast, Emotions, Endocrine Glands, Gastrointestinal Tract, Heart Rate, Immunity, Menstruation, Metabolism, Mucus, Nervous System, Physiology, Premenstrual Syndrome, Pulse, Respiration, Skin, Urine, Vitamins
Published
1965
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14. PHYSIOLOGIC CHANGES IN VITILIGO.

Author

CHANCO-TURNER ML and LERNER AB

Subjects
Humans, Acetylcholine, Blood Coagulation, Body Temperature, Epinephrine, Histamine, Metabolism, Norepinephrine, Pharmacology, Physiology, Skin, Sweating, Vitiligo
Published
1965

22. Testing the PPAR hypothesis of tobacco use disorder in humans: A randomized trial of the impact of gemfibrozil (a partial PPARα agonist) in smokers.

Author

Gendy, Marie N. S., Di Ciano, Patricia, Kowalczyk, William J., Barrett, Sean P., George, Tony P., Heishman, Stephen, and Le Foll, Bernard

Subjects
*GEMFIBROZIL, *PLACEBOS, *DRUG efficacy, *SMOKING cessation, *THERAPEUTICS, TOBACCO & health
Abstract

Previous pre-clinical studies demonstrated a promising role of alpha-type peroxisome proliferator-activated receptors (PPARα) agonists in decreasing nicotine self-administration and nicotine-seeking behavior in animals. Our goal was to investigate the potential of gemfibrozil, a PPARα agonist, on reducing tobacco smoking in humans. Methods: This was a double-blind, placebo-controlled, crossover study evaluating the effects of gemfibrozil (1200 mg/day) on smoking in 27 treatment-seeking smokers. The study had two 2-week phases separated by a washout period of at least 1 week. In each phase and after 1 week on medication, participants underwent a lab session where cue reactivity and forced choice paradigms were conducted. Physiological responses and self-reported craving were monitored during the presentation of smoking and neutral cues. In addition, two types of cigarettes were used in the forced choice paradigms: the Nicotinized cigarettes (Nic) and the Denicotinized cigarettes (Denic). The goal of the forced choice was to calculate the percentage of choice of Nic cigarettes while taking gemfibrozil or placebo. The number of quit days was calculated during the two quit attempts weeks (one while taking gemfibrozil and one while taking placebo) of the study. Results: There were no significant differences between gemfibrozil and placebo groups in the percentage of choice of Nic cigarettes, the cue-reactivity (both physiological and subjective measures), or in the number of days of abstinence. Conclusions: Although preclinical studies with PPAR α agonists showed promising results, this preliminary study did not demonstrate positive effect of gemfibrozil on tobacco use and cessation indices. [ABSTRACT FROM AUTHOR]

Published
2018
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23. Facial thermal variations: A new marker of emotional arousal.

Author

Kosonogov, Vladimir, De Zorzi, Lucas, Honoré, Jacques, Martínez-Velázquez, Eduardo S., Nandrino, Jean-Louis, Martinez-Selva, José M., and Sequeira, Henrique

Subjects
*THERMOGRAPHY, *EMOTIONS, *VISUAL perception, *GALVANIC skin response, *SKELETAL muscle
Abstract

Functional infrared thermal imaging (fITI) is considered a promising method to measure emotional autonomic responses through facial cutaneous thermal variations. However, the facial thermal response to emotions still needs to be investigated within the framework of the dimensional approach to emotions. The main aim of this study was to assess how the facial thermal variations index the emotional arousal and valence dimensions of visual stimuli. Twenty-four participants were presented with three groups of standardized emotional pictures (unpleasant, neutral and pleasant) from the International Affective Picture System. Facial temperature was recorded at the nose tip, an important region of interest for facial thermal variations, and compared to electrodermal responses, a robust index of emotional arousal. Both types of responses were also compared to subjective ratings of pictures. An emotional arousal effect was found on the amplitude and latency of thermal responses and on the amplitude and frequency of electrodermal responses. The participants showed greater thermal and dermal responses to emotional than to neutral pictures with no difference between pleasant and unpleasant ones. Thermal responses correlated and the dermal ones tended to correlate with subjective ratings. Finally, in the emotional conditions compared to the neutral one, the frequency of simultaneous thermal and dermal responses increased while both thermal or dermal isolated responses decreased. Overall, this study brings convergent arguments to consider fITI as a promising method reflecting the arousal dimension of emotional stimulation and, consequently, as a credible alternative to the classical recording of electrodermal activity. The present research provides an original way to unveil autonomic implication in emotional processes and opens new perspectives to measure them in touchless conditions. [ABSTRACT FROM AUTHOR]

Published
2017
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24. Safety aspects of atmospheric pressure helium plasma jet operation on skin: In vivo study on mouse skin.

Author

Kos, Spela, Blagus, Tanja, Sersa, Gregor, Cemazar, Maja, Filipic, Gregor, and Cvelbar, Uros

Subjects
*LOW temperature plasmas, *PHYSIOLOGICAL effects of atmospheric pressure, *HELIUM plasmas, *MICE, *SKIN, *DISSECTING microscopes, *INFRARED imaging
Abstract

Biomedical applications of plasma require its efficacy for specific purposes and equally importantly its safety. Herein the safety aspects of cold plasma created with simple atmospheric pressure plasma jet produced with helium gas and electrode discharge are evaluated in skin damage on mouse, at different duration of exposure and gas flow rates. The extent of skin damage and treatments are systematically evaluated using stereomicroscope, labelling with fluorescent dyes, histology, infrared imaging and optical emission spectroscopy. The analyses reveal early and late skin damages as a consequence of plasma treatment, and are attributed to direct and indirect effects of plasma. The results indicate that direct skin damage progresses with longer treatment time and increasing gas flow rates which reflect changes in plasma properties. With increasing flow rates, the temperature on treated skin grows and the RONS formation rises. The direct effects were plasma treatment dependent, whereas the disclosed late—secondary effects were more independent on discharge parameters and related to diffusion of RONS species. Thermal effects and skin heating are related to plasma-coupling properties and are separated from the effects of other RONS. It is demonstrated that cumulative topical treatment with helium plasma jet could lead to skin damage. How these damages can be mitigated is discussed in order to provide guidance, when using atmospheric pressure plasma jets for skin treatments. [ABSTRACT FROM AUTHOR]

Published
2017
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25. Warm hands, cold heart: progressive whole-body cooling increases warm thermosensitivity of human hands and feet in a dose-dependent fashion.

Author

Filingeri, Davide, Morris, Nathan B., and Jay, Ollie

Subjects
*BODY temperature, *STIMULUS & response (Biology), *VISION, *SKIN temperature, *HAND physiology, *FOOT physiology, *PHYSIOLOGY, PHYSIOLOGICAL aspects of pain
Abstract

New Findings What is the central question of this study? Investigations on inhibitory/facilitatory modulation of vision, touch and pain show that conditioning stimuli outside the receptive field of testing stimuli modulate the central processing of visual, touch and painful stimuli. We asked whether contextual modulation also exists in human temperature integration., What is the main finding and its importance? Progressive decreases in whole-body mean skin temperature (the conditioning stimulus) significantly increased local thermosensitivity to skin warming but not cooling (the testing stimuli) in a dose-dependent fashion. In resembling the central mechanisms underlying endogenous analgesia, our findings point to the existence of an endogenous thermosensory system in humans that could modulate local skin thermal sensitivity to facilitate thermal behaviour., Although inhibitory/facilitatory central modulation of vision and pain has been investigated, contextual modulation of skin temperature integration has not been explored. Hence, we tested whether progressive decreases in whole-body mean skin temperature ( Tsk; a large conditioning stimulus) alter the magnitude estimation of local warming and cooling stimuli applied to hairy and glabrous skin. On four separate occasions, eight men (27 ± 5 years old) underwent a 30 min whole-body cooling protocol (water-perfused suit; temperature, 5°C), during which a quantitative thermosensory test, consisting of reporting the perceived magnitude of warming and cooling stimuli (±8°C from 30°C baseline) applied to the hand (palm/dorsum) and foot (sole/dorsum), was performed before cooling and every 10 min thereafter. The cooling protocol resulted in large progressive reductions in Tsk [10 min, −3.36°C (95% confidence interval −2.62 to −4.10); 20 min, −5.21°C (−4.47 to −5.95); and 30 min, −6.32°C (−5.58 to −7.05); P < 0.001], with minimal changes (∼0.08°C) in rectal temperature. While thermosensitivity to local skin cooling remained unchanged ( P = 0.831), sensitivity to skin warming increased significantly at each level of Tsk for all skin regions [10 min, +4.9% (−1.1 to +11.0); 20 min, +6.1% (+0.1-12.2); and 30 min, +7.9% (+1.9-13.9); P = 0.009]. Linear regression indicated a 1.2% °C−1 increase in warm thermosensitivity with whole-body skin cooling. Overall, large decreases in Tsk significantly facilitated warm but not cold sensory processing of local thermal stimuli, in a dose-dependent fashion. In highlighting a novel feature of human temperature integration, these findings point to the existence of an endogenous thermosensory system that could modulate local skin thermal sensitivity in relationship to whole-body thermal states. [ABSTRACT FROM AUTHOR]

Published
2017
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26. Influence of age, sex, body condition score, rectal temperature, anatomical location and hair on skin pH in dogs

Author

Nausikaa Devriendt, Tri Bhawono Dadi, Hilde De Rooster, Louise Talloen, and Alexander Schlake

Subjects
Male, Future studies, Physiology, canine, Body Temperature, Dogs, Sex Factors, Body condition score, Concave surface, Animals, Medicine, Clinical significance, Prospective Studies, Veterinary Sciences, Prospective cohort study, Skin, Ph level, integumentary system, General Veterinary, business.industry, Age Factors, Rectal temperature, Hydrogen-Ion Concentration, Female, business, Wound healing, Hair
Abstract

Physiological skin pH levels are well-documented in human medicine, and assessment of variations may be important in assessing the efficacy of wound healing. By contrast, physiological skin pH levels in dogs are sparsely described.To determine the pH of intact skin in healthy dogs and to study the influence of different physiological factors on the pH level of canine skin.Seventy-seven client-owned dogs of various breeds, age and sex.A prospective study was designed and the pH of intact skin was measured at the concave surface of both pinnae, and in both axillary and inguinal regions. For each location, the colour and density of the hairs also was recorded. Each dog's rectal body temperature and body condition scores also were determined.The skin pH in dogs12 weeks of age was significantly lower (3.97-5.70) than in older dogs (4.40-8.18) (P 0.001). In dogs12 weeks of age, skin pH was significantly lower in the inguinal regions compared to the pinnae (P = 0.008), and female dogs had a significantly lower skin pH in the inguinal regions than male dogs (P = 0.043). Pinnae covered with light-coloured hair had a lower skin pH than those with dark-coloured hair (P = 0.04). No significant differences were found between dogs with different body condition scores, body temperatures or differences in hair density.The pH of intact healthy skin is lower in puppies of12 weeks of age. Regional differences of body location also were seen which were variably affected by hair colour and sex. A baseline assessment of skin pH in healthy dogs is important for future studies of disease and wound healing.Les niveaux de pH cutané physiologiques sont bine documentés en médecine humaine et déterminer les variations peut être important pour estimer l’efficacité de la cicatrisation. Au contraire, les niveaux de pH cutané physiologiques chez le chien sont peu décrits. HYPOTHÈSES/OBJECTIFS: Déterminer le pH de la peau intacte de chiens sains et étudier l’influence de différents facteurs physiologiques sur les valeurs de pH de la peau canine.Soixante dix sept chiens de propriétaires de race, âge et genre variés. MATÉRIELS ET MÉTHODES: Une étude prospective a été réalisée et le pH de la peau intacte a été mesuré à la surface concave des deux pavillons et dans les deux régions inguinales et axillaires. Pour chaque zone, la couleur et la densité des poils ont également été enregistrées. La température rectale et les scores corporels ont aussi été déterminés pour chaque chien. RÉSULTATS: Le pH cutané des chiens de moins de 12 semaines était significativement plus bas (3.97-5.70) que les chiens plus âgés (4.40-8.18) (P 0.001). Chez les chiens de plus de 12 semaines, le pH cutané était significativement plus faible dans les régions inguinales que sur les pavillons (P = 0.008), et les femelles avaient un pH cutané significativement plus faible dans les régions inguinales que les mâles (P = 0.043). Les pavillons recouverts de poils clairs avaient un pH cutané plus faible que ceux avec poils sombres (P = 0.04). Aucune différence significative n’a été trouvée entre les chiens en fonction de leurs scores corporels, des températures corporelles ou de la densité pilaire.Le pH de la peau cutanée intacte est plus faible chez les chiots de moins de 12 semaines. Les variations entre zones corporelles différentes ont aussi été observées, ce qui est affecté par la couleur des poils ou par le genre. Une détermination du pH cutané de base chez le chien sains est importante pour de futures études de pathologie ou de cicatrisation cutanée.INTRODUCCIÓN: los niveles fisiológicos de pH de la piel están bien documentados en medicina humana y la evaluación de las variaciones puede ser importante para valorar la eficacia de la cicatrización de heridas. Por el contrario, los niveles de pH fisiológico de la piel en perros se han descrito raramente. HIPÓTESIS/OBJETIVOS: Determinar el pH de la piel intacta en perros sanos y estudiar la influencia de diferentes factores fisiológicos en el nivel de pH de la piel canina. ANIMALES: setenta y siete perros de propietarios particulares de diversas razas, edades y sexos MÉTODOS Y MATERIALES: se diseñó un estudio prospectivo y se midió el pH de la piel intacta en la superficie cóncava de ambos pabellones auditivos y en las regiones axilar e inguinal. Para cada ubicación también se anotó el color y la densidad de los pelos. Igualmente se determinaron los valores de la temperatura corporal rectal y la condición corporal de cada perro. RESULTADOS: El pH de la piel en perros12 semanas de edad fue significativamente más bajo (3,97-5,70) que en perros mayores (4,40-8,18) (P0,001). En perros12 semanas de edad, el pH de la piel fue significativamente más bajo en las regiones inguinales en comparación con el pabellón auricular (P = 0,008), y las hembras tenían un pH cutáneo significativamente más bajo en las regiones inguinales que los perros machos (P = 0,043). Las orejas cubiertas con cabello de color claro tenían un pH cutáneo más bajo que aquellas con cabello de color oscuro (P = 0,04). No se encontraron diferencias significativas entre perros con diferentes valores de condición corporal, temperaturas corporales o diferencias en la densidad del pelo. CONCLUSIONES Y RELEVANCIA CLÍNICA: El pH de la piel sana intacta es más bajo en cachorros de12 semanas de edad. También se observaron diferencias regionales de ubicación corporal que se vieron afectadas de manera variable por el color del cabello y el sexo. Una evaluación de referencia del pH de la piel en perros sanos es importante para futuros estudios de enfermedades y cicatrización de heridas.Physiologische pH Werte der Haut sind in der Humanmedizin gut dokumentiert und eine Erhebung von Variationen könnte bei der Erhebung ihrer Wirksamkeit bei der Wundheilung von Bedeutung sein. Im Gegensatz dazu sind physiologische pH Werte der Haut beim Hund nur selten beschrieben.Eine Bestimmung des pH Wertes intakter Haut bei gesunden Hunden und eine Untersuchung der Einflussnahme unterschiedlicher physiologischer Faktoren auf die pH Werte von Hundehaut.Siebenundsiebzig Hunde verschiedener Rasse, Alters und Geschlechts, die sich in Privatbesitz befanden.Eine prospektive Studie wurde designed und der pH Wert intakter Haut an der konkaven Oberfläche beider Pinnae, sowie beider Achseln und der Inguinalregion gemessen. Für jede Lokalisation wurde die Farbe und Dichtheit der Haare ebenfalls bestimmt. Die Rektaltemperatur eines jeden Hundes und die Werte des Allgemeinzustandes des Körpers wurden erhoben.Der pH Wert der Haut bei Hunden12 Wochen Lebensalter war signifikant niedriger (3,97-5,70) als bei älteren Hunden (4,40-8,18)(P0,001). Bei Hunden12 Wochen Lebensalter war der pH Wert der Haut in der Inguinalregion signifikant niedriger im Vergleich zu den Pinnae (P = 0,008), und weibliche Hunde hatte einen signifikant niedrigeren pH der Haut in der Inguinalregion als männliche Hunde (P = 0,043). Pinnae, die mit hellen Haaren bedeckt waren, zeigten einen niedrigeren pH Wert als solche, die mit dunkelgefärbten Haaren bedeckt waren (P = 0,04). Es wurden keine signifikanten Unterschiede zwischen den verschiedenen Allgemeinbefunden, der Körpertemperatur oder der Haardichte gefunden.Der pH Wert intakter gesunder Haut ist bei Welpen12 Wochen niedriger. Regionale Unterschiede in Bezug auf die Körperlokalisation konnten ebenfalls festgestellt werden, diese waren in unterschiedlichem Ausmaß von Haarfarbe und Geschlecht beeinflusst. Ein Basiswert für den pH Wert der Haut ist bei gesunden Hunden für weitere Studien von Erkrankungen und Wundheilung wichtig.背景: 人の皮膚の生理的pH値はよく知られており、その変動を評価することは創傷治癒の効果を評価する上で重要である。対照的に、犬の生理的な皮膚のpHレベルはほとんど記述されていない。 仮説/目的: 本研究の目的は、健常犬の無傷の皮膚pHを測定し、犬の皮膚pHレベルに対するさまざまな生理学的因子の影響を研究することであった。 供試動物: 様々な品種、年齢、性別のオーナー所有の犬77頭。 材料と方法: 前向き研究がデザインされ、無傷の皮膚pHは、両耳介の凹面、および両腋窩および鼠径部で測定された。それぞれの部位で、毛の色および密度も記録した。また、各犬の直腸体温およびボディコンディションスコアを測定した。 結果: 12週齢未満の犬の皮膚pHは、高齢の犬 (4.40-8.18) よりも有意に低かった (3.97-5.70) (P0.001) 。12週齢以上の犬では、鼠径部の皮膚pHは耳介部に比べて有意に低く (P = 0.008) 、雌犬は雄犬に比べて鼠径部の皮膚pHが有意に低かった (P = 0.043) 。明るい色の毛で覆われた耳介部は、暗い色の毛で覆われた耳介よりも皮膚pHが低かった (P = 0.04) 。ボディコンディションスコア、体温、毛の密度が異なる犬の間では、有意な差は見られなかった。 結論と臨床的関連性: 無傷の健常皮膚pHは、12週齢未満の子犬では低いことがわかった。また、体の部位による領域差が見られ、これは毛色や性別によっても影響を受ける。健常犬の皮膚pHをベースラインで評価することは、今後の疾患や創傷治癒の研究に重要である。.背景: 生理皮肤pH水平在人类医学中有充分记录,评估变化可能对评估伤口愈合的有效性很重要。相比之下, 犬的生理性皮肤pH水平描述很少。 假设/目的: 测定健康犬完整皮肤的pH值, 并研究不同生理因素对犬皮肤pH水平的影响。 动物: 77只不同品种、年龄和性别的客户拥有的犬。 方法和材料: 设计前瞻性研究, 测量双侧耳廓凹面、腋窝和腹股沟区域完整皮肤的pH值。对于每个位置, 还记录了毛发的颜色和密度。还测定了每只犬的直肠体温和身体状况评分。 结果:12周龄犬的皮肤pH值(3.97-5.70)显著低于老年犬(4.40-8.18)(P0.001)。在12周龄的犬中, 与耳廓相比, 腹股沟区域的皮肤pH值显著降低(P = 0.008), 雌性犬腹股沟区域的皮肤pH值显著低于雄性犬(P = 0.043)。被浅色毛发覆盖的耳廓皮肤pH值低于被深色毛发覆盖的耳廓(P = 0.04)。不同身体状况评分、体温或毛发密度差异的犬之间未发现显著差异。 结论和临床相关性:12周龄幼犬的完整健康皮肤pH值较低。还观察到身体位置的区域差异, 其受毛发颜色和性别的不同影响。健康犬皮肤pH值的基线评估对于未来疾病和伤口愈合研究非常重要。.Os níveis fisiológicos de pH da pele são bem documentados na medicina humana e a avaliação das variações pode ser importante para avaliar a eficácia da cicatrização de feridas. Em contraste, os níveis fisiológicos de pH da pele em cães são pouco descritos. HIPÓTESE/OBJETIVOS: Determinar o pH da pele intacta em cães saudáveis e estudar a influência de diferentes fatores fisiológicos no nível de pH da pele canina.Setenta e sete cães de propriedade privada de várias raças, idade e sexo. MÉTODOS E MATERIAIS: Um estudo prospectivo foi delineado e o pH da pele íntegra foi mensurado na superfície côncava de ambas as orelhas e nas regiões axilar e inguinal. Para cada local, a cor e a densidade dos pelos também foram registradas. A temperatura retal de cada cão e os escores de condição corporal também foram determinados.O pH da pele em cães com12 semanas de idade foi significativamente menor (3,97-5,70) do que em cães mais velhos (4,40-8,18) (P0,001). Em cães com12 semanas de idade, o pH da pele foi significativamente menor na região inguinal em comparação com os pavilhões auriculares (P=0,008), e as cadelas tiveram um pH de pele significativamente mais baixo na região inguinal do que os cães machos (P=0,043). Os pavilhões auriculares recobertos por pelos claros apresentaram pH cutâneo inferior ao daqueles com pelos escuros (P=0,04). Não foram encontradas diferenças significativas entre cães com diferentes escores de condição corporal, temperatura corporal ou diferenças na densidade do pelo. CONCLUSÕES E RELEVÂNCIA CLÍNICA: O pH da pele saudável intacta é mais baixo em cães com12 semanas de idade. Diferenças regionais de localização corporal também foram observadas, as quais foram afetadas de forma variável pela cor do pelo e gênero. É importante que seja realizada uma avaliação inicial do pH da pele em cães saudáveis em estudos futuros sobre doenças e cicatrização de feridas.

Published
2022

27. Development of a Consistent and Reproducible Porcine Scald Burn Model.

Author

Andrews, Christine J., Kempf, Margit, Kimble, Roy, and Cuttle, Leila

Subjects
*PATHOLOGICAL physiology, *DISEASE progression, *TISSUE wounds, *BURNS & scalds, *LABORATORY swine
Abstract

There are very few porcine burn models that replicate scald injuries similar to those encountered by children. We have developed a robust porcine burn model capable of creating reproducible scald burns for a wide range of burn conditions. The study was conducted with juvenile Large White pigs, creating replicates of burn combinations; 50°C for 1, 2, 5 and 10 minutes and 60°C, 70°C, 80°C and 90°C for 5 seconds. Visual wound examination, biopsies and Laser Doppler Imaging were performed at 1, 24 hours and at 3 and 7 days post-burn. A consistent water temperature was maintained within the scald device for long durations (49.8 ± 0.1°C when set at 50°C). The macroscopic and histologic appearance was consistent between replicates of burn conditions. For 50°C water, 10 minute duration burns showed significantly deeper tissue injury than all shorter durations at 24 hours post-burn (p ≤ 0.0001), with damage seen to increase until day 3 post-burn. For 5 second duration burns, by day 7 post-burn the 80°C and 90°C scalds had damage detected significantly deeper in the tissue than the 70°C scalds (p ≤ 0.001). A reliable and safe model of porcine scald burn injury has been successfully developed. The novel apparatus with continually refreshed water improves consistency of scald creation for long exposure times. This model allows the pathophysiology of scald burn wound creation and progression to be examined. [ABSTRACT FROM AUTHOR]

Published
2016
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28. Phenotypic Plasticity through Transcriptional Regulation of the Evolutionary Hotspot Gene tan in Drosophila melanogaster.

Author

Gibert, Jean-Michel, Mouchel-Vielh, Emmanuèle, De Castro, Sandra, and Peronnet, Frédérique

Subjects
*BIOLOGICAL evolution, *PHENOTYPIC plasticity, *DROSOPHILA melanogaster, *DNA methylation, *HUMAN skin color
Abstract

Phenotypic plasticity is the ability of a given genotype to produce different phenotypes in response to distinct environmental conditions. Phenotypic plasticity can be adaptive. Furthermore, it is thought to facilitate evolution. Although phenotypic plasticity is a widespread phenomenon, its molecular mechanisms are only beginning to be unravelled. Environmental conditions can affect gene expression through modification of chromatin structure, mainly via histone modifications, nucleosome remodelling or DNA methylation, suggesting that phenotypic plasticity might partly be due to chromatin plasticity. As a model of phenotypic plasticity, we study abdominal pigmentation of Drosophila melanogaster females, which is temperature sensitive. Abdominal pigmentation is indeed darker in females grown at 18°C than at 29°C. This phenomenon is thought to be adaptive as the dark pigmentation produced at lower temperature increases body temperature. We show here that temperature modulates the expression of tan (t), a pigmentation gene involved in melanin production. t is expressed 7 times more at 18°C than at 29°C in female abdominal epidermis. Genetic experiments show that modulation of t expression by temperature is essential for female abdominal pigmentation plasticity. Temperature modulates the activity of an enhancer of t without modifying compaction of its chromatin or level of the active histone mark H3K27ac. By contrast, the active mark H3K4me3 on the t promoter is strongly modulated by temperature. The H3K4 methyl-transferase involved in this process is likely Trithorax, as we show that it regulates t expression and the H3K4me3 level on the t promoter and also participates in female pigmentation and its plasticity. Interestingly, t was previously shown to be involved in inter-individual variation of female abdominal pigmentation in Drosophila melanogaster, and in abdominal pigmentation divergence between Drosophila species. Sensitivity of t expression to environmental conditions might therefore give more substrate for selection, explaining why this gene has frequently been involved in evolution of pigmentation. [ABSTRACT FROM AUTHOR]

Published
2016
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29. Ownership and Agency of an Independent Supernumerary Hand Induced by an Imitation Brain-Computer Interface.

Author

Bashford, Luke and Mehring, Carsten

Subjects
*PSYCHOLOGICAL ownership, *BRAIN-computer interfaces, *VIRTUAL reality, *PHYSICAL activity, *HUMAN anatomy
Abstract

To study body ownership and control, illusions that elicit these feelings in non-body objects are widely used. Classically introduced with the Rubber Hand Illusion, these illusions have been replicated more recently in virtual reality and by using brain-computer interfaces. Traditionally these illusions investigate the replacement of a body part by an artificial counterpart, however as brain-computer interface research develops it offers us the possibility to explore the case where non-body objects are controlled in addition to movements of our own limbs. Therefore we propose a new illusion designed to test the feeling of ownership and control of an independent supernumerary hand. Subjects are under the impression they control a virtual reality hand via a brain-computer interface, but in reality there is no causal connection between brain activity and virtual hand movement but correct movements are observed with 80% probability. These imitation brain-computer interface trials are interspersed with movements in both the subjects’ real hands, which are in view throughout the experiment. We show that subjects develop strong feelings of ownership and control over the third hand, despite only receiving visual feedback with no causal link to the actual brain signals. Our illusion is crucially different from previously reported studies as we demonstrate independent ownership and control of the third hand without loss of ownership in the real hands. [ABSTRACT FROM AUTHOR]

Published
2016
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30. Incubation Temperature during Fetal Development Influences Morphophysiological Characteristics and Preferred Ambient Temperature of Chicken Hatchlings.

Author

Morita, Viviane de Souza, Almeida, Vitor Rosa de, JuniorMatos, João Batista, Vicentini, Tamiris Iara, van den Brand, Henry, and Boleli, Isabel Cristina

Subjects
*FETAL development, *CHICKENS, *BODY temperature, *BROILER chickens, *EGGSHELLS, *EGG incubation, *PHYSIOLOGY
Abstract

Skin and feather characteristics, which play a critical role in body temperature maintenance, can be affected by incubation circumstances, such as incubation temperature. However, no study to date has assessed the influence of incubation temperature during the fetal stage on morphometric characteristics and vascular development of the skin, feather characteristics, and their relationship to hormone levels and preferred temperature in later life in chickens. Broiler breeder eggs were exposed to low (36°C), control (37.5°C), or high (39°C) temperatures (treatments LT, CK, and HT, respectively) from day 13 of incubation onward, because it is known that the endocrine axes are already established at this time. During this period, eggshell temperature of HT eggs (38.8±0.33°C) was higher than of LT (37.4±0.08°C) and CK eggs (37.8 ±0.15°C). The difference between eggshell and incubator air temperature diminished with the increasing incubation temperature, and was approximately zero for HT. HT hatchlings had higher surface temperature on the head, neck, and back, and thinner and more vascularized skin than did CK and LT hatchlings. No differences were found among treatments for body weight, total feather weight, number and length of barbs, barbule length, and plasma T4 concentration. LT hatchlings showed lower plasma T3 and GH, as well as lower T3/T4 ratio and decreased vascularity in the neck, back, and thigh skin compared to CK hatchlings. On the other hand, HT hatchlings had decreased skin thickness and increased vascularity, and preferred a higher ambient temperature compared to CK and HT hatchlings. In addition, for all treatments, surface temperature on the head was higher than of the other body regions. We conclude that changes in skin thickness and vascularity, as well as changes in thyroid and growth hormone levels, are the result of embryonic strategies to cope with higher or lower than normal incubation temperatures. Additionally exposure to increased temperature during incubation is an environmental factor that can exert early-life influence on ambient temperature preference of broiler hatchlings in later life. [ABSTRACT FROM AUTHOR]

Published
2016
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31. The effect of short and continuous absorbent patch application on local skin temperature underneath

Author

Lisa Klous, Hein A.M. Daanen, Mireille Folkerts, Nicola Gerrett, Physiology, AMS - Musculoskeletal Health, AMS - Ageing & Vitality, and AMS - Sports

Subjects
Hot Temperature, Right scapula, Physiology, 0206 medical engineering, Skin temperature, Biomedical Engineering, Biophysics, Sweating, 02 engineering and technology, Body Temperature, SWEAT, 03 medical and health sciences, Absorbent patch, 0302 clinical medicine, Animal science, Physiology (medical), Humans, Sweat, Skin, integumentary system, Chemistry, 020601 biomedical engineering, Sweat rate, Local, Left scapula, Exercise intensity, Right upper arm, 030217 neurology & neurosurgery, Body Temperature Regulation
Abstract

Objective. By attaching absorbent patches to the skin to collect sweat, an increase in local skin temperature (T sk) underneath the patches seems unavoidable. Yet this effect has not been quantified. The present study investigates the effect of absorbent patch application on local T sk underneath. Approach. Ten healthy participants cycled for 60 min at an exercise intensity relative to their body surface area (40 W.m−2) in three environmental conditions (temperate: 25 °C 45% RH, hot-humid: 33 °C 65% RH and hot-dry: 40 °C 30% RH). The effect of short sweat sampling (i.e. from min 25–30 to min 55–60) on T sk was examined on the right scapula. T sk of the left scapula served as control. The effect of continuous sweat sampling (i.e. four consecutive 15 min periods) on T sk was examined on the right upper arm. T sk of the left upper arm served as control. Main results. Neither short nor continuous application of absorbent sweat patches affected T sk underneath the patches in the hot-humid and hot-dry condition (P > 0.05). In the temperate condition, continuous application led to a significant increase in T sk underneath the patches during the first and second minute. This increase remained throughout the experiment (1.8 ± 0.6 °C; P T sk underneath (P > 0.05) in the temperate condition. Significance. To avoid a significant increase in local T sk underneath sweat patches, continuous application should be prevented in, especially, a temperate condition. Timely removal of sweat patches should be taken into account during longer periods of collecting sweat in field or laboratories settings.

Published
2021

32. Independent and combined impact of hypoxia and acute inorganic nitrate ingestion on thermoregulatory responses to the cold

Author

Josh Arnold, Alex Lloyd, Stephen J. Bailey, Naoto Fujii, Simon Hodder, Physiotherapy, Human Physiology and Anatomy, and Human Physiology and Sports Physiotherapy Research Group

Subjects
Adult, Male, Physiology, Administration, Oral, Placebo, Body Temperature, Nitric oxide, chemistry.chemical_compound, Nitrate, Physiology (medical), medicine, Humans, Ingestion, Orthopedics and Sports Medicine, Hypoxia, Skin, Nitrates, business.industry, Microcirculation, Shivering, Public Health, Environmental and Occupational Health, General Medicine, Thermoregulation, Hypoxia (medical), Anapyrexia, Cold Temperature, chemistry, Vasoconstriction, Anesthesia, Original Article, medicine.symptom, business, Cold
Abstract

Purpose This study assessed the impact of normobaric hypoxia and acute nitrate ingestion on shivering thermogenesis, cutaneous vascular control, and thermometrics in response to cold stress. Method Eleven male volunteers underwent passive cooling at 10 °C air temperature across four conditions: (1) normoxia with placebo ingestion, (2) hypoxia (0.130 FiO2) with placebo ingestion, (3) normoxia with 13 mmol nitrate ingestion, and (4) hypoxia with nitrate ingestion. Physiological metrics were assessed as a rate of change over 45 min to determine heat loss, and at the point of shivering onset to determine the thermogenic thermoeffector threshold. Result Independently, hypoxia expedited shivering onset time (p = 0.05) due to a faster cooling rate as opposed to a change in central thermoeffector thresholds. Specifically, compared to normoxia, hypoxia increased skin blood flow (p = 0.02), leading to an increased core-cooling rate (p = 0.04) and delta change in rectal temperature (p = 0.03) over 45 min, yet the same rectal temperature at shivering onset (p = 0.9). Independently, nitrate ingestion delayed shivering onset time (p = 0.01), mediated by a change in central thermoeffector thresholds, independent of changes in peripheral heat exchange. Specifically, compared to placebo ingestion, no difference was observed in skin blood flow (p = 0.5), core-cooling rate (p = 0.5), or delta change in rectal temperature (p = 0.7) over 45 min, while nitrate reduced rectal temperature at shivering onset (p = 0.04). No interaction was observed between hypoxia and nitrate ingestion. Conclusion These data improve our understanding of how hypoxia and nitric oxide modulate cold thermoregulation.

Published
2021

33. Increased brain l-arginine availability facilitates cutaneous heat loss induced by running exercise.

Author

Wanner, Samuel Penna, Leite, Laura Hora Rios, Guimarães, Juliana Bohnen, and Coimbra, Cândido Celso

Subjects
*PHYSIOLOGICAL effects of arginine, *PHYSIOLOGICAL aspects of running, *TREADMILL exercise, *BODY temperature regulation, *FATIGUE (Physiology), *NITRIC oxide synthesis, *PHYSIOLOGY
Abstract

The effects of increased brain availability of l-arginine ( l-arg), a precursor for nitric oxide synthesis, on core body temperature ( Tcore) and cutaneous heat loss were evaluated in running rats. One week prior to the experiments, adult male Wistar rats received the following implants: a chronic guide cannula in the lateral cerebral ventricle and a temperature sensor in the abdominal cavity. On the day of the experiments, the rats were assigned to receive a 2- μL intracerebroventricular injection of either NaCl (0.15 mol/L) or l-arg solution (0.825, 1.65 or 3.30 mol/L); Tcore and tail skin temperature were measured while the rats ran at a speed of 18 m/min until they were fatigued. l-arginine induced a dose-dependent reduction in the threshold Tcore required for cutaneous heat loss (38.09 ± 0.20°C for 3.30-mol/L l-arg vs 38.61 ± 0.10°C for saline; P < 0.05), which attenuated the exercise-induced hyperthermia. Although the rats treated with l-arg presented a lower Tcore at the end of exercise (~0.7°C lower after treatment with the highest dose), no changes in the time to fatigue were observed relative to the control trial. These results suggest that brain l-arg controls heat loss during exercise, most likely by modulating the sympathetic vasoconstrictor tonus to skin vessels. Furthermore, despite facilitating cutaneous heat loss mechanisms, increased brain l-arg availability did not enhance physical performance. [ABSTRACT FROM AUTHOR]

Published
2015
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34. The effect of constitutive pigmentation on the measured emissivity of human skin

Author

Mark R. Sims, Jonathan P. Thompson, Timothy J Coats, Sophie A. Stanley, Matthew Charlton, Victoria Wenn, and Zoë Whitman

Subjects
Male, Light, Infrared, Physiology, Human skin, Skin Pigmentation, Electrical tape, 030218 nuclear medicine & medical imaging, Body Temperature, 030207 dermatology & venereal diseases, Fitzpatrick scale, 0302 clinical medicine, Spectrum Analysis Techniques, Medicine and Health Sciences, Ethnicity, Ethnicities, Prospective Studies, Skin, Multidisciplinary, integumentary system, Infrared Radiation, Physics, Electromagnetic Radiation, Skin temperature, Middle Aged, Healthy Volunteers, Physiological Parameters, Spectrophotometry, Thermography, Physical Sciences, Medicine, Female, Anatomy, Integumentary System, Research Article, Adult, Materials science, Visible Light, Coronavirus disease 2019 (COVID-19), Infrared Rays, Science, Absorption (skin), Research and Analysis Methods, 03 medical and health sciences, Young Adult, Emissivity, Humans, Aged, SARS-CoV-2, Biology and Life Sciences, COVID-19, People and Places, Population Groupings, Skin Temperature, Biomedical engineering
Abstract

Background The measurement of body temperature has become commonplace in the current COVID-19 pandemic. Body temperature can be measured using thermal infrared imaging, a safe, non-contact method that relies on the emissivity of the skin being known to provide accurate readings. Skin pigmentation affects the absorption of visible light and enables us to see variations in skin colour. Pigmentation may also affect the absorption of infrared radiation and thus affect thermal imaging. Human skin has an accepted emissivity of 0.98 but the effect of different skin pigmentation on this value is not known. In this study, we investigated the influence of different skin pigmentation on thermal emissivity in 65 adult volunteers. Methods A reference object of known emissivity (electrical tape) was applied to participant’s skin on the inner upper arm. Tape and arm were imaged simultaneously using a thermal infrared camera. The emissivity was set on the camera to the known value for electrical tape. The emissivity was altered manually until the skin temperature using thermal imaging software was equal to the initial tape temperature. This provided the calculated emissivity value of the skin. Participants were grouped according to skin pigmentation, quantified using the Fitzpatrick skin phototyping scale and reflectance spectrophotometry. Differences in emissivity values between skin pigmentation groups were assessed by one-way ANOVA. Results The mean calculated emissivity for the 65 participants was 0.972 (range 0.96–0.99). No significant differences in emissivity were observed between participants when grouped by skin pigmentation according to the Fitzpatrick scale (p = 0.859) or reflectance spectrophotometry (p = 0.346). Conclusion These data suggest that skin pigmentation does not affect thermal emissivity measurement of skin temperature using thermal infrared imaging. This study will aid further research into the application of thermal infrared imaging as a screening or bedside diagnostic tool in clinical practice.

Published
2020

35. A test-retest reliability study of assessing small cutaneous fibers by measuring current perception threshold with pin electrodes

Author

Fanqi Meng, Han Fu, Haiying Liu, Kaifeng Wang, and Weiwei Xia

Subjects
Male, endocrine system diseases, Physiology, Social Sciences, Concentric, Body Temperature, 0302 clinical medicine, Nerve Fibers, Medical Conditions, Animal Cells, Reliability study, Blood Flow, Medicine and Health Sciences, Psychology, heterocyclic compounds, Immune Response, Skin, Neurons, 0303 health sciences, Multidisciplinary, Skin temperature, Middle Aged, Body Fluids, Blood, Physiological Parameters, Neurology, Touch Perception, Sensory Thresholds, Electrode, Medicine, Sensory Perception, Female, Cellular Types, Anatomy, Research Article, Adult, endocrine system, China, Materials science, Correlation coefficient, Science, Coefficient of variation, Immunology, Sensation, Pain, Surgical and Invasive Medical Procedures, 03 medical and health sciences, Signs and Symptoms, Humans, neoplasms, Electrodes, Physical Examination, 030304 developmental biology, Inflammation, Functional Electrical Stimulation, Cognitive Psychology, Biology and Life Sciences, Reproducibility of Results, Cell Biology, digestive system diseases, Electric Stimulation, Neuropathy, Touch, Cellular Neuroscience, Cognitive Science, Perception, Clinical Medicine, Skin Temperature, 030217 neurology & neurosurgery, Biomedical engineering, Neuroscience
Abstract

Background The quantitative measurement of current perception threshold (CPT) has been used as a method to assess the function of nerve fibers in neuropathy diseases. The aim of this study was to assess the test-retest reliability measuring CPT using the circular pin electrodes for assessing the function of cutaneous thin nerve fibers. Methods CPT measurement was repeated on two separate days with at least one-week interval in 55 volunteers. Superficial blood flow (SBF) and skin temperature (ST) were measured on the skin in an around area concentric to the circular pin electrodes after the process of finding CPTs. The coefficient of variation (CV) and intra-class correlation coefficient (ICC) were calculated. The correlation between each two of CPT, SBF increment and ST increment was analyzed. Results No significant differences were found for CPT, SBF and ST between two sessions. SBF was found to be significantly increased after the process of finding CPT. CPT values of males were found to be higher than females. SBF increment was found to be positively correlated with ST increment. The ICC values for CPT, SBF and ST were 0.595, 0.852 and 0.728, respectively. The CV values for CPT, SBF and ST were 25.53%, 12.59% and 1.94%, respectively. Conclusions The reliability of CPT measurement using circular pin electrodes is fair, and need consistence of measurements in longitudinal studies.

Published
2020

36. Does skin surface temperature variation account for Buruli ulcer lesion distribution?

Author

Paul Dr Johnson, Arvind Yerramilli, Nicola K. Sexton-Oates, and Andrew J. Stewardson

Subjects
Male, Bacterial Diseases, 0301 basic medicine, Buruli ulcer, Physiology, RC955-962, Pathology and Laboratory Medicine, Body Temperature, 0302 clinical medicine, Arctic medicine. Tropical medicine, Healthy volunteers, Medicine and Health Sciences, Medicine, Child, Buruli Ulcer, Musculoskeletal System, Skin, biology, Incidence (epidemiology), Temperature, Soft tissue, Surface Temperature, Middle Aged, Healthy Volunteers, Actinobacteria, Infectious Diseases, Physiological Parameters, Mycobacterium ulcerans, Physical Sciences, Female, Anatomy, medicine.symptom, Public aspects of medicine, RA1-1270, Research Article, Neglected Tropical Diseases, Adult, medicine.medical_specialty, Adolescent, Surface Properties, Skin surface temperature, Materials Science, Material Properties, 030231 tropical medicine, Lesion, Young Adult, 03 medical and health sciences, Signs and Symptoms, Diagnostic Medicine, Humans, Distribution (pharmacology), Aged, Bacteria, business.industry, Organisms, Public Health, Environmental and Occupational Health, Biology and Life Sciences, Tropical Diseases, medicine.disease, biology.organism_classification, Dermatology, Biting, 030104 developmental biology, Age Groups, Body Limbs, People and Places, Lesions, Population Groupings, Skin Temperature, business
Abstract

BackgroundBuruli ulcer is a necrotising infection of skin and soft tissue caused by Mycobacterium ulcerans (M. ulcerans). Buruli ulcer most often occurs on limbs, and it is hypothesized this is explained by direct exposure to the environment. However, even on exposed areas Buruli ulcer is not randomly distributed. M. ulcerans prefers an in vitro temperature of 30-33°C and growth is inhibited at higher temperatures. This study investigated whether variations in skin surface temperature distribution in healthy volunteers could partly account for Buruli ulcer lesion distribution.Methodology/Principal FindingsIn this observational study, a thermal camera (FLIR E8) was used to measure skin surface temperature at the sternal notch and at 44 predetermined locations on the limbs of 18 human participants. Body locations of high, middle and low Buruli ulcer incidence were identified from existing density maps of lesion distribution. Skin temperature of the three incidence location groups were compared, and differences in age and sex groups were also analysed.We found an inverse relationship between skin temperature and lesion distribution, where high incidence locations were significantly cooler and low incidence locations significantly warmer (Kruskal-Wallis test pConclusions/SignificanceWe have found an inverse relationship between skin temperature and Buruli ulcer lesion distribution, however this association is weak. Additional unknown factors are likely to be involved that explain the majority of the variation in Buruli lesion distribution.Author SummaryBuruli ulcer is a destructive soft tissue infection caused by the bacterium Mycobacterium ulcerans. The precise mode of transmission remains unknown. One theory proposes that transmission occurs by direct contact with a contaminated environment. Lesions occur mostly on limbs, and it is hypothesized this is explained by direct exposure to the environment. However even on exposed areas, lesions are not randomly distributed. This study investigated whether skin surface temperature can partly explain Buruli ulcer lesion distribution. We measured the skin surface temperature of 18 healthy participants using a thermal camera and compared temperature distribution to the distribution of Buruli ulcer lesions investigated in a previously published study. We found that there is a negative correlation between skin temperature and Buruli ulcer lesion incidence. However, the association is weak and other factors e.g. clothing choice and insect biting patterns may explain the majority of Buruli ulcer lesion distribution.

Published
2020

37. The influence of menthol on thermoregulation and perception during exercise in warm, humid conditions.

Author

Gillis, D. Jason, House, James R., and Tipton, Michael J.

Subjects
*MENTHOL, *BODY temperature regulation, *EXERCISE, *PHYSICAL diagnosis, *HEMODYNAMICS, *ALCOHOLS (Chemical class), *BLOOD circulation, *BODY temperature, *CLINICAL trials, *COMPARATIVE studies, *EXERCISE tests, *HEAT, *HUMIDITY, *RESEARCH methodology, *MEDICAL cooperation, *SENSORY perception, *PERSPIRATION, *PULMONARY gas exchange, *RESEARCH, *RESPIRATION, *SKIN, *EVALUATION research, *SKIN temperature, *OXYGEN consumption, *PHYSIOLOGY
Abstract

Menthol has recently been added to various cooling products that claim to enhance athletic performance. This study assessed the effect of two such solutions during exercise in warm, humid conditions. Twelve participants (22 ± 2.9 years; VO2peak 47.4 ± 6.2 mL kg(-1) min(-1)) completed a peak power (PO(peak)) test and three separate exercise bouts in 30°C and 70% relative humidity after being sprayed with 100 mL of water containing either 0.05 or 0.2% l-menthol, or a control spray. During each trial, participants underwent 15 min of rest, spraying, 15 min of rest and 45 min of exercise at 45% of PO(peak). The following variables were measured: rectal temperature (T (re)), sweat rate (SR), skin blood flow (SBF), heart rate (HR), thermal comfort (TC) and sensation (TS) votes, irritation (IRR) and rating of perceived exertion (RPE). Mean skin (MST) and body temperatures (Tbody) were calculated. There was no significant difference in MST, Tbody SR, SBF, HR, TC or RPE between conditions. Spraying with 0.2% menthol significantly (P < 0.05) elevated T (re) by 0.2°C compared to the other conditions. Both menthol sprays caused participants to feel significantly cooler than control spraying (P = 0.001), but 0.2% spraying induced significantly cooler sensations (P = 0.01) than 0.05% spraying. Both menthol sprays induced greater irritation (P < 0.001) than control spraying. These findings suggest that 0.05% menthol spraying induced cooler upper body sensations without measurable thermoregulatory impairment. T (re) was significantly elevated with 0.2% spraying. Irritation persisted with both menthol sprays while TC remained unchanged, suggesting a causal relationship. The use in sport of a spray similar to those tested here remains equivocal. [ABSTRACT FROM AUTHOR]

Published
2010
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38. Aerobically trained individuals have greater increases in rectal temperature than untrained ones during exercise in the heat at similar relative intensities.

Author

Mora-Rodriguez, Ricardo, Del Coso, Juan, Hamouti, Nassim, Estevez, Emma, and Ortega, Juan F.

Subjects
*DEHYDRATION, *PERSPIRATION, *HEMODYNAMICS, *BLOOD circulation, *SKIN temperature, *QUALITATIVE research, *RECTUM physiology, *BODY temperature, *COMPARATIVE studies, *EXERCISE, *HEAT, *RESEARCH methodology, *MEDICAL cooperation, *PHYSICAL fitness, *RESEARCH, *SKIN, *WATER-electrolyte balance (Physiology), *EVALUATION research, *OXYGEN consumption, *PHYSIOLOGY
Abstract

To determine if the increases in rectal temperature (T(REC)) during exercise in the heat at a given percent of VO2peak depend on a subject's aerobic fitness level. On three occasions, 10 endurance-trained (Tr) and 10 untrained (UTr) subjects (VO2peak: 60 +/- 6 vs. 44 +/- 3 mL kg(-1) min(-1), P < 0.05) cycled in a hot-dry environment (36 +/- 1 degrees C; 25 +/- 2% humidity, airflow 2.5 m s(-1)) at three workloads (40, 60, and 80% VO2peak). At the same percent of VO2peak, on average, Tr had 28 +/- 5% higher heat production but also higher skin blood flow (29 +/- 3%) and sweat rate (20 +/- 7%; P = 0.07) and lower skin temperature (0.5 degrees C; P < 0.05). Pre-exercise T(REC) was lower in the Tr subjects (37.4 +/- 0.2 vs. 37.6 +/- 0.2; P < 0.05) but similar to the UTr at the end of 40 and 60% VO2peak trials. Thus, exercise T(REC) increased more in the Tr group than in the UTr group (0.6 +/- 0.1 vs. 0.3 +/- 0.1 degrees C at 40% VO2peak and 1.0 +/- 0.1 vs. 0.6 +/- 0.3 degrees C at 60% VO2peak; P < 0.05). At 80% VO2peak not only the increase in T(REC) (1.7 +/- 0.1 vs. 1.3 +/- 0.3 degrees C) but also the final T(REC) was larger in Tr than in UTr subjects (39.15 +/- 0.1 vs. 38.85 +/- 0.1 degrees C; P < 0.05). During exercise in the heat at the same relative intensity, aerobically trained individuals have a larger rise in T(REC) than do the untrained ones which renders them more hyperthermic after high-intensity exercise. [ABSTRACT FROM AUTHOR]

Published
2010
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39. Changes in blood flow in conduit artery and veins of the upper arm during leg exercise in humans.

Author

Ooue, Anna, Ichinose, Tomoko, Inoue, Yoshimitsu, Nishiyasu, Takeshi, Koga, Shunsaku, Kondo, Narihiko, and Ichinose, Tomoko K

Subjects
*BLOOD flow, *ARTERIES, *LEG exercises, *VEINS, *BODY temperature, *PHYSIOLOGY, *LEG physiology, *DOPPLER ultrasonography, *ARM, *BLOOD circulation, *BLOOD flow measurement, *BLOOD pressure, *CARDIOVASCULAR disease diagnosis, *COMPARATIVE studies, *EXERCISE, *HEART beat, *HEMODYNAMICS, *RESEARCH methodology, *MEDICAL cooperation, *MUSCLE contraction, *RESEARCH, *SKIN, *EVALUATION research, *BRACHIAL artery, *BRACHIOCEPHALIC veins
Abstract

This study investigated changes in blood flow in the conduit artery, superficial vein, and deep vein of the upper arm during increase in internal temperature due to leg cycling. Additionally, we sought to demonstrate the contributions of blood velocity and vessel diameter on blood flow responses. Fourteen subjects performed supine cycling exercise at 60-69% maximal oxygen uptake for 30 min at an ambient temperature of 28 degrees C and relative humidity of 50%. Blood velocity and diameter in the brachial artery, basilic vein (superficial vein), and brachial vein (deep vein) were measured using ultrasound Doppler, and blood flow was calculated. Blood flow in the artery and superficial vein increased linearly with rising oesophageal temperature (DeltaT (oes)) after DeltaT (oes) was about 0.3 degrees C (within threshold), as well as cutaneous vascular conductance on the forearm. Changes in blood velocity in these vessels were similar to those in blood flow. Conversely, the brachial artery and superficial vein diameter did not affect the blood flow response. Blood flow variables in the deep vein did not change remarkably with rising DeltaT (oes). These results suggest that blood flow response, by an increase in velocity, in the conduit artery with rising DeltaT (oes) during exercise is similar to that in the superficial vein, but not deep vein. Also, it is indicated that these increases in blood flow relate to the increase in skin blood flow on the forearm with the rise in body temperature during exercise. [ABSTRACT FROM AUTHOR]

Published
2008
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40. Facial cold-induced vasodilation and skin temperature during exposure to cold wind.

Author

Brajkovic, Dragan and Ducharme, Michel B.

Subjects
*VASODILATION, *PHYSIOLOGICAL effects of cold temperatures, *SKIN, *WIND speed, *EXERCISE physiology, *NOSE physiology, *RECTUM physiology, *BODY temperature, *COLD (Temperature), *FACE, *WEATHER, *SKIN temperature, *PHYSIOLOGY
Abstract

One purpose of this study was to characterize the facial skin temperature and cold-induced vasodilation (CIVD) response of 12 subjects (six males and six females) during exposure to cold wind (i.e., -10 to 10 degrees C; 2, 5, and 8 m/s wind speed). This study found that at each wind speed, facial skin temperature decreased as ambient temperature decreased. The percentage of subjects showing facial CIVD decreased significantly at an ambient temperature above -10 degrees C. A similar CIVD percentage was observed between 0 degrees C dry and 10 degrees C wet (face sprayed with fine water mist) at each wind speed. No CIVDs were observed during the 10 degrees C dry condition at any wind speed. The incidence of CIVD response was more uniform across facial sites when there was a greater cold stress (i.e., -10 degrees C and 8 m/s wind). Another objective of the study was to examine the effect of the thermal state of the body (as reflected by core temperature) on the facial skin temperature response during rest and exercise. This study found that nose skin temperature was significantly higher in exercising subjects with an elevated core temperature even though there was no significant difference in face skin temperature between the two conditions. Therefore, this finding suggests that acral regions of the face, such as the nose, are more sensitive to changes in the thermal state of the body, and hence will stay warmer relative to other parts of the face during exercise in the cold. [ABSTRACT FROM AUTHOR]

Published
2006
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41. Cutaneous warming promotes sleep onset.

Author

Raymann, Roy J. E. M., Swaab, Dick F., and Van Someren, Eus J. W.

Subjects
*SLEEP, *BODY temperature, *SKIN, *BLOOD flow, *PHYSIOLOGY, *VITAL signs
Abstract

Sleep occurs in close relation to changes in body temperature. Both the monophasic sleep period in humans and the polyphasic sleep periods in rodents tend to be initiated when core body temperature is declining. This decline is mainly due to an increase in skin blood flow and consequently skin warming and heat loss. We have proposed that these intrinsically occurring changes in core and skin temperatures could modulate neuronal activity in sleep-regulating brain areas (Van Someren EJW, Chronobiol Int 17:313-54, 2000). We here provide results compatible with this hypothesis. We obtained 144 sleep-onset latencies while directly manipulating core and skin temperatures within the comfortable range in eight healthy subjects under controlled conditions. The induction of a proximal skin temperature difference of only 0.78 ± 0.03°C (mean ± SE) around a mean of 35.13 ± 0.11°C changed sleep-onset latency by 26%, i.e., by 3.09 minutes [95% confidence interval (CI), 1.91 to 4.28] around a mean of 11.85 mm (CI, 9.74 to 14.41), with faster sleep onsets when the proximal skin was warmed. The reduction in sleep-onset latency occurred despite a small but significant decrease in subjective comfort during proximal skin warming. The induction of changes in core temperature (δ = 0.20 ± 0.02°C) and distal skin temperature (δ = 0.74 ± 0.05°C) were ineffective. Previous studies have demonstrated correlations between skin temperature and sleep-onset latency. Also, sleep disruption by ambient temperatures that activate thermoregulatory defense mechanisms has been shown. The present study is the first to experimentally demonstrate a causal contribution to sleep-onset latency of skin temperature manipulations within the normal nocturnal fluctuation range. Circadian and sleep-appetitive behavior-induced variations in skin temperature might act as an input signal to sleep-regulating systems. [ABSTRACT FROM AUTHOR]

Published
2005
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42. Body cooling effects of immersion of the forearms in high-concentration artificial carbonic acid water at 25°C

Author

Yuuki Tanaka, Hisaho Nagano, and Akihiro Taimura

Subjects
Adult, Male, Body cooling, 010504 meteorology & atmospheric sciences, Physiology, Human Factors and Ergonomics, lcsh:GN49-298, Heat stroke, Thermal sensation, Core temperature, 01 natural sciences, Body Temperature, 03 medical and health sciences, chemistry.chemical_compound, Young Adult, 0302 clinical medicine, Animal science, Tap water, Physiology (medical), Heart rate, Immersion (virtual reality), Humans, Orthopedics and Sports Medicine, Relative humidity, Exercise, 0105 earth and related environmental sciences, Skin, Carbonic acid, lcsh:Physical anthropology. Somatology, Chemistry, Artificial carbonic acid water, Public Health, Environmental and Occupational Health, 030229 sport sciences, Cold Temperature, Forearm, Cryotherapy, Anthropology, Carbonic Acid, Skin blood flow, Original Article, Cooling
Abstract

BACKGROUND: This study examined the effects of immersion in stirred, high-concentration, artificial carbonic acid water on body cooling. METHODS: Seven healthy male students (23 ± 2 years old) participated in the experiment. Signed informed consent was obtained from all subjects before the experiment. The subjects changed into shorts and T-shirts and entered an experimental room (with room temperature controlled at 30 °C and relative humidity maintained at 70%) at least 30 min before starting the experiment. After starting the experiment, the subjects were asked to rest on an exercise bike for 5 min and then pedal for 20 min. The exercise load was set to reach 50% of each subject's presumed maximum oxygen intake at 5 min after starting exercise. Subjects then continued pedaling for 1 min to cool down. After this exercise, subjects sat on a chair and immersed forearms in tap water or artificial carbonic acid water (CO2 water) at 25 °C for 20 min. During immersion, tap water or CO2 water was stirred slowly with a pump. After immersion, subjects rested for 10 min. Skin temperature and skin blood flow (left forearm), as well as heart rate and ear canal temperature, were measured continuously. Thermal sensation and thermal comfort were measured intermittently. RESULTS: Skin blood flow of the immersed forearms was higher in CO2 water than in tap water during immersion. The blood flow in the last 5 min (average at rest was 100%) was significantly higher in CO2 water (290.85 ± 84.81%) than in tap water (104.80 ± 21.99%). Thermal sensation and thermal comfort were not different between conditions. Ear canal temperature significantly declined more in CO2 water (-?0.56 ± 0.31 °C) than in tap water (-?0.48 ± 0.30 °C) during immersion. CONCLUSIONS: Our study suggests that immersion of the forearms in slowly stirred CO2 water at 25 °C reduces core temperature elevated by heat stress or exercise more effectively than does tap water at the same temperature. Immersion of the forearms in stirred CO2 water at 25 °C could be useful as a preventive measure against heat stroke from summer work or exercise., Journal of physiological anthropology, 39, art.no.2; 2020

Published
2020

43. Circadian Rhythms in Body Temperature of the Pigtaled Macaque (Macaca nemestrina) Exposed to Different Ambient Temperatures.

Author

Wurster, Ellen C., Murrish, David E., and Sulzman, Frank M.

Subjects
*MEDICAL thermometry, *PIG-tailed macaque, *BODY temperature, *ATMOSPHERIC temperature, *MACAQUES, *BODY temperature regulation, *CIRCADIAN rhythms, *BIOLOGICAL rhythms, *SKIN, *VASOMOTOR system, *PHYSIOLOGY, *PRIMATES
Abstract

The body and leg skin temperatures of five pigtailed macaques (Macaca nemestrina) were measured at various ambient air temperatures ranging from 22 to 32°C over 24-h periods. The rhythm in core body temperature persisted in all ambient air temperatures, and the rhythm in leg skin temperature was suppressed at the higher and lower ambient temperatures. This suggests that at the upper and lower regions of the thermoneutral zone, either a rhythm in heat production or a heat loss rhythm other than leg skin temperature is regulating the core body temperature rhythm. It was also found that the mean colonic temperature increased linearly with an increase in ambient temperature and that a phase relationship existed between ambient temperature and colonic temperature. In addition, as the ambient temperature increased, additional sites along the distal portion of the leg were recruited for vasomotor heat loss. [ABSTRACT FROM AUTHOR]

Published
1985
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44. Testing the PPAR hypothesis of tobacco use disorder in humans: A randomized trial of the impact of gemfibrozil (a partial PPARα agonist) in smokers

Author

Bernard Le Foll, Stephen J. Heishman, William J. Kowalczyk, Sean P. Barrett, Patricia Di Ciano, Marie N. S. Gendy, and Tony P. George

Subjects
0301 basic medicine, Skin Physiology, Male, Pulmonology, Physiology, medicine.medical_treatment, lcsh:Medicine, Social Sciences, Craving, Pharmacology, Body Temperature, Nicotine, Habits, 0302 clinical medicine, Heart Rate, Smoking Habits, Medicine and Health Sciences, Gemfibrozil, Psychology, Public and Occupational Health, lcsh:Science, media_common, Skin, Smoking Cessation Agents, Multidisciplinary, Smoking, Middle Aged, Nicotine Addiction, Chemistry, Physiological Parameters, Research Design, Physical Sciences, Female, medicine.symptom, Anatomy, Integumentary System, medicine.drug, Research Article, Adult, Substance-Related Disorders, media_common.quotation_subject, Cardiology, Addiction, Laboratory Tests, Placebo, Research and Analysis Methods, 03 medical and health sciences, Alkaloids, Double-Blind Method, Mental Health and Psychiatry, medicine, Humans, PPAR alpha, Behavior, business.industry, lcsh:R, Chemical Compounds, Biology and Life Sciences, Smoking Related Disorders, Abstinence, Crossover study, 030104 developmental biology, Cross-Sectional Studies, Cue reactivity, Smoking cessation, lcsh:Q, Smoking Cessation, business, Skin Temperature, 030217 neurology & neurosurgery
Abstract

Previous pre-clinical studies demonstrated a promising role of alpha-type peroxisome proliferator-activated receptors (PPARα) agonists in decreasing nicotine self-administration and nicotine-seeking behavior in animals. Our goal was to investigate the potential of gemfibrozil, a PPARα agonist, on reducing tobacco smoking in humans. Methods This was a double-blind, placebo-controlled, crossover study evaluating the effects of gemfibrozil (1200 mg/day) on smoking in 27 treatment-seeking smokers. The study had two 2-week phases separated by a washout period of at least 1 week. In each phase and after 1 week on medication, participants underwent a lab session where cue reactivity and forced choice paradigms were conducted. Physiological responses and self-reported craving were monitored during the presentation of smoking and neutral cues. In addition, two types of cigarettes were used in the forced choice paradigms: the Nicotinized cigarettes (Nic) and the Denicotinized cigarettes (Denic). The goal of the forced choice was to calculate the percentage of choice of Nic cigarettes while taking gemfibrozil or placebo. The number of quit days was calculated during the two quit attempts weeks (one while taking gemfibrozil and one while taking placebo) of the study. Results There were no significant differences between gemfibrozil and placebo groups in the percentage of choice of Nic cigarettes, the cue-reactivity (both physiological and subjective measures), or in the number of days of abstinence. Conclusions Although preclinical studies with PPAR α agonists showed promising results, this preliminary study did not demonstrate positive effect of gemfibrozil on tobacco use and cessation indices.

Published
2018

45. Two subspecies of bent-winged bats (Miniopterus orianae bassanii and oceanensis) in southern Australia have diverse fungal skin flora but not Pseudogymnoascus destructans

Author

Linda F. Lumsden, Glenn F. Browning, Marc S. Marenda, Peter H. Holz, and Jasmin Hufschmid

Subjects
0301 basic medicine, Range (biology), Physiology, Endangered species, lcsh:Medicine, Artificial Gene Amplification and Extension, Subspecies, Pathology and Laboratory Medicine, Population density, Polymerase Chain Reaction, Body Temperature, Geographical Locations, Critically endangered, Chiroptera, Bats, Medicine and Health Sciences, DNA, Fungal, lcsh:Science, Skin, Mammals, Fungal Pathogens, Multidisciplinary, biology, Miniopterus, Fungal Diseases, Eukaryota, Population decline, Infectious Diseases, Physiological Parameters, Medical Microbiology, Vertebrates, Histoplasma Capsulatum, Pathogens, Research Article, animal structures, 030106 microbiology, Oceania, Zoology, Mycology, Nose, Research and Analysis Methods, Microbiology, 03 medical and health sciences, Ascomycota, Pseudogymnoascus destructans, Animals, Molecular Biology Techniques, Microbial Pathogens, Molecular Biology, Population Density, Endangered Species, lcsh:R, Organisms, Fungi, Australia, Biology and Life Sciences, Sequence Analysis, DNA, biology.organism_classification, 030104 developmental biology, Amniotes, People and Places, North America, lcsh:Q
Abstract

Fungi are increasingly being documented as causing disease in a wide range of faunal species, including Pseudogymnoascus destructans, the fungus responsible for white nose syndrome which is having a devastating impact on bats in North America. The population size of the Australian southern bent-winged bat (Miniopterus orianae bassanii), a critically endangered subspecies, has declined over the past 50 years. As part of a larger study to determine whether disease could be a contributing factor to this decline, southern bent-winged bats were tested for the presence of a range of potentially pathogenic fungi: P. destructans, dermatophytes and Histoplasma capsulatum (a potential human pathogen commonly associated with caves inhabited by bats). Results were compared with those obtained for the more common eastern bent-winged bat (M. orianae oceanensis). All bats and their environment were negative for P. destructans. A large number of fungi were found on the skin and fur of bats, most of which were environmental or plant associated, and none of which were likely to be of significant pathogenicity for bats. A 0–19% prevalence of H. capsulatum was detected in the bat populations sampled, but not in the environment, indicative of a low zoonotic risk. Based on the results of this study, fungi are unlikely to be contributing significantly to the population decline of the southern bent-winged bat.

Published
2018

46. THE EFFECT OF SKIN TEMPERATURE AND VASCULAR CHANGE ON THE RATE OF TRANSEPIDERMAL WATER LOSS.

Author

Grice, Katherine and Bettley, F. Ray

Subjects
VASODILATION, PHYSIOLOGY, VITAL signs, FEVER, SKIN, BODY temperature
Abstract

Vasoconstriction and vasodilation had no significant effect on transepidermal water loss (TWL), and the galvanic skin resistance was unaffected. Decreasing skin temperature was accompanied by decreasing TWL. The fall appeared to be related to skin temperature and not directly to the reduction in body temperature. No significant difference in the TWL was found between skin rendered anhidrotic by poldine and untreated skin in which sweating could not be detected. [ABSTRACT FROM AUTHOR]

Published
1967
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47. Modelling hand skin temperature in relation to body composition

Author

Rongling Li, W Wim Zeiler, Brm Boris Kingma, Katarina Katic, RS: NUTRIM - R1 - Obesity, diabetes and cardiovascular health, RS: NUTRIM - HB/BW section B, RS: NUTRIM - R1 - Metabolic Syndrome, Building Services, and Energy Technology

Subjects
Male, 010504 meteorology & atmospheric sciences, Physiology, PREDICTION, Skin temperature, Obesity/physiopathology, 02 engineering and technology, SDG 3 – Goede gezondheid en welzijn, 01 natural sciences, Biochemistry, Body composition, Body Temperature, Models, 0202 electrical engineering, electronic engineering, information engineering, Medicine, HUMAN THERMOREGULATION, Skin, integumentary system, Anatomy, Skin/blood supply, ENVIRONMENTAL-CONDITIONS, Energy expenditure, Female, General Agricultural and Biological Sciences, OBESE WOMEN, Body Temperature Regulation, THERMAL COMFORT, Blood temperature, 020209 energy, HEAT, Models, Biological, SDG 3 - Good Health and Well-being, SENSATIONS, Maximum difference, Humans, Obesity, 0105 earth and related environmental sciences, BLOOD-FLOW, business.industry, Skin blood flow, Hand/physiology, ENERGY-EXPENDITURE, Blood flow, Hand, Biological, Absolute deviation, Hand temperature, BUILT ENVIRONMENT, Normal weight, Thermophysiological model, business, Developmental Biology, Biomedical engineering
Abstract

Skin temperature is a challenging parameter to predict due to the complex interaction of physical and physiological variations. Previous studies concerning the correlation of regional physiological characteristics and body composition showed that obese people have higher hand skin temperature compared to the normal weight people. To predict hand skin temperature in a different environment, a two-node hand thermophysiological model was developed and validated with published experimental data. In addition, a sensitivity analysis was performed which showed that the variations in skin blood flow and blood temperature are most influential on hand skin temperature. The hand model was applied to simulate the hand skin temperature of the obese and normal weight subgroup in different ambient conditions. Higher skin blood flow and blood temperature were used in the simulation of obese people. The results showed a good agreement with experimental data from the literature, with the maximum difference of 0.31 degrees C. If the difference between blood flow and blood temperature of obese and normal weight people was not taken into account, the hand skin temperature of obese people was predicted with an average deviation of 1.42 degrees C. In conclusion, when modelling hand skin temperatures, it should be considered that regional skin temperature distribution differs in obese and normal weight people.

Published
2017

48. Sustained increases in skin blood flow are not a pre-requisite to initiate sweating during passive heat exposure

Author

Nicholas Ravanelli, Daniel Gagnon, Ollie Jay, and Université de Montréal. Faculté de médecine. Département de pharmacologie et physiologie

Subjects
Male, Thermotolerance, medicine.medical_specialty, Physiology, Sudomotor, Vasodilation, Sweating, 030204 cardiovascular system & hematology, Thermoregulation, Heat stress, 03 medical and health sciences, Young Adult, 0302 clinical medicine, Physiology (medical), Internal medicine, Skin Physiological Phenomena, medicine, Humans, Body temperature, Skin, integumentary system, Chemistry, Skin blood flow, Surgery, Cardiology, 030217 neurology & neurosurgery, Blood Flow Velocity, Heat-Shock Response, Body Temperature Regulation, Research Article
Abstract

Some studies have observed a functional relationship between sweating and skin blood flow. However, the implications of this relationship during physiologically relevant conditions remain unclear. We manipulated sudomotor activity through changes in sweating efficiency to determine if parallel changes in vasomotor activity are observed. Eight young men completed two trials at 36°C and two trials at 42°C. During these trials, air temperature remained constant while ambient vapor pressure increased from 1.6 to 5.6 kPa over 2 h. Forced airflow across the skin was used to create conditions of high (HiSeff) or low (LoSeff) sweating efficiency. Local sweat rate (LSR), local skin blood flow (SkBF), as well as mean skin and esophageal temperatures were measured continuously. It took longer for LSR to increase during HiSeff at 36°C (HiSeff: 99 ± 11 vs. LoSeff: 77 ± 11 min, P < 0.01) and 42°C (HiSeff: 72 ± 16 vs. LoSeff: 51 ± 15 min, P < 0.01). In general, an increase in LSR preceded the increase in SkBF when expressed as ambient vapor pressure and time for all conditions ( P < 0.05). However, both responses were activated at a similar change in mean body temperature (average across all trials, LSR: 0.26 ± 0.15 vs. SkBF: 0.30 ± 0.18°C, P = 0.26). These results demonstrate that altering the point at which LSR is initiated during heat exposure is paralleled by similar shifts for the increase in SkBF. However, local sweat production occurs before an increase in SkBF, suggesting that SkBF is not necessarily a prerequisite for sweating.

Published
2017

49. Elevated skin and core temperatures both contribute to reductions in tolerance to a simulated haemorrhagic challenge

Author

James Pearson, Zachary J. Schlader, Rebekah A. I. Lucas, Daniel Gagnon, and Craig G. Crandall

Subjects
Hyperthermia, Adult, Male, Fever, Physiology, Stress index, Hemorrhage, 030204 cardiovascular system & hematology, Core temperature, Heat Stress Disorders, Article, Syncope, Body Temperature, 03 medical and health sciences, 0302 clinical medicine, Physiology (medical), medicine, Humans, Increased skin temperature, Skin, Lower Body Negative Pressure, Presyncope, Core (anatomy), Nutrition and Dietetics, business.industry, Skin temperature, General Medicine, Hyperthermia, Induced, medicine.disease, Anesthesia, Female, business, 030217 neurology & neurosurgery, Heat-Shock Response, Military activity
Abstract

NEW FINDINGS What is the central question of this study? Combined increases in skin and core temperatures reduce tolerance to a simulated haemorrhagic challenge. The aim of this study was to examine the separate and combined influences of increased skin and core temperatures upon tolerance to a simulated haemorrhagic challenge. What is the main finding and its importance? Skin and core temperatures increase during many occupational settings, including military procedures, in hot environments. The study findings demonstrate that both increased skin temperature and increased core temperature can impair tolerance to a simulated haemorrhagic challenge; therefore, a soldier's tolerance to haemorrhagic injury is likely to be impaired during any military activity that results in increased skin and/or core temperatures. Tolerance to a simulated haemorrhagic insult, such as lower-body negative pressure (LBNP), is profoundly reduced when accompanied by whole-body heat stress. The aim of this study was to investigate the separate and combined influence of elevated skin (Tskin ) and core temperatures (Tcore ) on LBNP tolerance. We hypothesized that elevations in Tskin as well as Tcore would both contribute to reductions in LBNP tolerance and that the reduction in LBNP tolerance would be greatest when both Tskin and Tcore were elevated. Nine participants underwent progressive LBNP to presyncope on four occasions, as follows: (i) control, with neutral Tskin (34.3 ± 0.5°C) and Tcore (36.8 ± 0.2°C); (ii) primarily skin hyperthermia, with high Tskin (37.6 ± 0.2°C) and neutral Tcore (37.1 ± 0.2°C); (iii) primarily core hyperthermia, with neutral Tskin (35.0 ± 0.5°C) and high Tcore (38.3 ± 0.2°C); and (iv) combined skin and core hyperthermia, with high Tskin (38.8 ± 0.6°C) and high Tcore (38.1 ± 0.2°C). The LBNP tolerance was quantified via the cumulative stress index (in millimetres of mercury × minutes). The LBNP tolerance was reduced during the skin hyperthermia (569 ± 151 mmHg min) and core hyperthermia trials (563 ± 194 mmHg min) relative to control conditions (1010 ± 246 mmHg min; both P

Published
2017

50. Safety aspects of atmospheric pressure helium plasma jet operation on skin: In vivo study on mouse skin

Author

Maja Cemazar, Gregor Sersa, Uroš Cvelbar, Tanja Blagus, Gregor Filipič, and Spela Kos

Subjects
Hot Temperature, Plasma Gases, Physiology, Diffusion, Glycobiology, lcsh:Medicine, Helium, Biochemistry, 01 natural sciences, Body Temperature, 010305 fluids & plasmas, Mice, Medicine and Health Sciences, lcsh:Science, Glucans, Flow Rate, Skin, 010302 applied physics, Mice, Inbred BALB C, Jet (fluid), Multidisciplinary, Atmospheric pressure, Physics, Classical Mechanics, Volumetric flow rate, Chemistry, Atmospheric Pressure, Physiological Parameters, Physical Sciences, Female, Anatomy, Research Article, Chemical Elements, States of Matter, medicine.medical_specialty, Histology, Materials science, Imaging Techniques, chemistry.chemical_element, Atmospheric-pressure plasma, Fluid Mechanics, Research and Analysis Methods, Continuum Mechanics, Polysaccharides, In vivo, Tissue Repair, Fluorescence Imaging, Burns, Chemical, 0103 physical sciences, medicine, Animals, Dextran, Wound Healing, lcsh:R, Biology and Life Sciences, Fluid Dynamics, Plasma, Surgery, Microscopy, Fluorescence, chemistry, Plasmas, Biophysics, lcsh:Q, Physiological Processes, Skin Temperature
Abstract

Biomedical applications of plasma require its efficacy for specific purposes and equally importantly its safety. Herein the safety aspects of cold plasma created with simple atmospheric pressure plasma jet produced with helium gas and electrode discharge are evaluated in skin damage on mouse, at different duration of exposure and gas flow rates. The extent of skin damage and treatments are systematically evaluated using stereomicroscope, labelling with fluorescent dyes, histology, infrared imaging and optical emission spectroscopy. The analyses reveal early and late skin damages as a consequence of plasma treatment, and are attributed to direct and indirect effects of plasma. The results indicate that direct skin damage progresses with longer treatment time and increasing gas flow rates which reflect changes in plasma properties. With increasing flow rates, the temperature on treated skin grows and the RONS formation rises. The direct effects were plasma treatment dependent, whereas the disclosed late-secondary effects were more independent on discharge parameters and related to diffusion of RONS species. Thermal effects and skin heating are related to plasma-coupling properties and are separated from the effects of other RONS. It is demonstrated that cumulative topical treatment with helium plasma jet could lead to skin damage. How these damages can be mitigated is discussed in order to provide guidance, when using atmospheric pressure plasma jets for skin treatments.

Published
2017

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