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Results 251 - 300 of 1109
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Coris Eric Emmanuel - - 2007
Heat illness is the third leading cause of death in athletics and a leading cause of morbidity and mortality in exercising athletes. Once faced with a case of heat related illness, severe or mild, the health care professional is often faced with the question of when to reactivate the athlete ...
Armstrong Lawrence E - - 2007
Exertional heat exhaustion (HEX) is the most common form of heat illness experienced by athletes, laborers, and military personnel. Both dehydration stemming from a water and/or salt deficiency and a high ambient temperature must exist for HEX to occur. In the field, appropriate therapy can reduce recovery time. This manuscript ...
de Castro E Paula L A - - 2007
Exposure of oocytes to elevated temperature (i.e. heat shock) during maturation can reduce fertilization rate and development of the resultant embryos. Given the possible role of free radicals in actions of heat shock on cellular function, we tested the hypothesis that a high oxygen environment exacerbates the magnitude of deleterious ...
Armstrong Lawrence E - - 2007
Dietitians, exercise physiologists, athletic trainers, and other sports medicine personnel commonly recommend that exercising adults and athletes refrain from caffeine use because it is a diuretic, and it may exacerbate dehydration and hyperthermia. This review, contrary to popular beliefs, proposes that caffeine consumption does not result in the following: (a) ...
Yamanaka Yoshitaka - - 2007
BACKGROUND: Local heating of non-glabrous skin increases skin blood flow (SkBF) in two phases: the initial peak (P1) is mediated by sensory axon reflex, and the plateau phase (P2) is thought to be mediated by local production of substances including nitric oxide. We evaluated P1 and P2 responses in subacute ...
Cheuvront Samuel N - - 2007
Sweat prediction equations are often used outside their boundaries to estimate fluid requirements and generate guidance. The limitations associated with these generalized predictions have not been characterized. The purposes of this study were to: (1) evaluate the accuracy of a widely used sweat prediction equation (SHAP) when widening it's boundaries ...
Noakes Timothy David - - 2008
This article proposes a novel framework classification for the heat illnesses. It argues that heat stroke is the only described condition that is truly a "heat illness" since it is the only condition in which there is clear evidence for a pathological elevation of the core body temperature. If this ...
Pietrzak William S - - 2007
Heating bioabsorbable plates above T(g) allows for temporary softening to facilitate adaptation to bone. This can, however, transiently alter the mechanical properties, a better understanding of which would provide further insight into the use of these polymers. Two types of unoriented L-lactide/glycolide copolymer wafer specimens (82:18 and 95:5 molar ratios) ...
Davis Scott L - - 2007
The aim of this investigation was to identify the consequences of skin grafting on cutaneous vasodilation and sweating in split-thickness grafted skin during indirect whole-body heating 5 to 9 months after surgery. In addition, thermoregulatory function was examined at donor skin sites on a separate day. Skin blood flow and ...
Demchak Timothy J - - 2007
CONTEXT: Ultrasound heating rates are known to differ between various manufacturers; it is unknown whether this difference exists within a manufacturer. OBJECTIVE: Determine if intramuscular heating differences exist between transducers from the same manufacturer. STUDY DESIGN: 3 x 10 repeated measures. Independent variables were Transducer (A, B, and C) and ...
Bishop David - - 2007
PURPOSE: Team sports contain high-intensity sprints separated by active recovery (AR) and passive recovery (PR). The beneficial effects of AR on repeated-sprint performance, for short exercise duration, in thermoneutral environments, are well known. However, team sports are often performed in hot environments for prolonged periods. Therefore, the aim was to ...
Allen Michael J - - 2007
Because no scientific literature exists regarding endodontic pathfinders, the aim of this study was to compare such instruments. Ten different pathfinder-type files were analyzed with respect to dimensional characteristics, pitch, and rigidity; efficiency, wear, and distortion were assessed by using an in vitro simulation exercise. SEM cross-sections and tip images ...
Wanner Samuel P - - 2007
The aim of this study was to evaluate the participation of ventromedial hypothalamic nucleus (VMH) muscarinic cholinoceptors in heat balance and central fatigue during treadmill exercise (24 m min(-1), 5% inclination). The animals were anesthetized with pentobarbital sodium (50 mg/kg body weight i.p.) and fitted with bilateral cannulae into the ...
- - 2007
Exertional heat illness can affect athletes during high-intensity or long-duration exercise and result in withdrawal from activity or collapse during or soon after activity. These maladies include exercise associated muscle cramping, heat exhaustion, or exertional heatstroke. While certain individuals are more prone to collapse from exhaustion in the heat (i.e., ...
Kenefick R W - - 2007
This study examined the effects of rehydration (Rehy) with fluids of varying tonicities and routes of administration after exercise-induced hypohydration on exercise performance, fluid regulatory hormone responses, and cardiovascular and thermoregulatory strain during subsequent exercise in the heat. On four occasions, eight men performed an exercise-dehydration protocol of approximately 185 ...
Appenzeller Brice M R - - 2007
In the present work, we assessed the suitability of sodium and potassium physiologically present in sweat, as internal reference allowing to re-calculate the corresponding volume of sweat collected on a PharmChek Patch. A method using capillary electrophoresis with indirect ultra-violet detection was developed for the determination of sodium and potassium ...
- - 2007
This Position Stand provides guidance on fluid replacement to sustain appropriate hydration of individuals performing physical activity. The goal of prehydrating is to start the activity euhydrated and with normal plasma electrolyte levels. Prehydrating with beverages, in addition to normal meals and fluid intake, should be initiated when needed at ...
Brace Christopher L - - 2007
To evaluate the performance of a 17-gauge triaxial antenna at microwave ablation in an in vivo porcine liver model. This study was approved by the institutional animal care and use committee. Thirteen female domestic pigs (mean weight, 45 kg) were used. Ablations were performed with a prototype microwave ablation system ...
Low David A - - 2007
We tested the hypothesis that local heating-induced nitric oxide (NO) production attenuates cutaneous vasoconstrictor responsiveness. Eleven subjects (6 men, 5 women) had four microdialysis membranes placed in forearm skin. Two membranes were perfused with 10 mM of N(G)-nitro-L-arginine (L-NAME) and two with Ringer solution (control), and all sites were locally ...
Xu Guihua - - 2007
This paper reports the effects of heat treatment on huyou (Citrus paradisi Changshanhuyou) peel in terms of phenolic compounds and antioxidant capacity. High-performance liquid chromatography (HPLC) coupled with a photodiode array (PDA) detector was used in this study for the analysis of phenolic acids (divided into four fractions: free, ester, ...
Prímola-Gomes Thales N - - 2007
The aim of this study was to evaluate the effects of stimulation of the central cholinergic pathway on the regulation of post-exercise tail heat loss in rats. Either 2.0microL of 25x10(-3)M physostigmine (Phy) or 0.15M NaCl solution (Sal) were injected into the right lateral cerebral ventricle of both resting (n=8) ...
Bruce-Low S S - - 2007
Fire fighter breathing apparatus instructors (BAIs) must possess the ability to respond to both the extrinsic stress of a high temperature environment and the intrinsic stress from wearing personal protective equipment (PPE) and self-contained breathing apparatus (SCBA), repeatedly and regularly, whilst training recruits in live fire training exercises (LFTEs). There ...
Rowland T - - 2007
The goal of this study was to identify factors which limit exercise endurance in hot ambient conditions in prepubertal boys. Eight healthy non-acclimatized, highly physically active prepubertal boys performed steady load cycling at approximately 65 % peak VO (2) to exhaustion in both cool (19.6 +/- 0.6 degrees C, 66.4 ...
Glogau Richard G - - 2007
OBJECTIVE: The objective was to demonstrate that botulinum toxin type A (BTX-A) can be delivered to targeted skin sites with topical application for the treatment of primary axillary hyperhidrosis. METHODS: This randomized, blinded, vehicle-controlled study enrolled 12 patients with primary axillary hyperhidrosis with greater than 50 mg of sweat produced ...
Ganio Matthew S - - 2007
Studies related to fundamental hydration issues have required clinicians to re-examine certain practices and concepts. The ingestion of substances such as creatine, caffeine, and glycerol has been questioned in regards to safety and hydration status. Reports of overdrinking (hyponatremia) also have brought into question the practices of drinking appropriate fluid ...
Cheung Stephen S - - 2007
Traditionally, exercise in the heat has been assumed to be primarily limited by cardiovascular constraints. However, an evolutionary perspective suggests that psychological safeguards should also protect individuals prior to catastrophic hyperthermia, and exposure to hot environments or elevated body temperature may directly attenuate central drive for exercise even well before ...
Noakes Timothy D - - 2007
Early human ancestors evolved hunting in the midday heat on the dry African savannah and developed favourable biological adaptations that permit prolonged running in the heat. These physiological adaptations must have included the capacity to sweat profusely to maintain a low body temperature when running for 4-6 hours in dry ...
Horowitz Michal - - 2007
The fundamental functions of heat shock proteins (HSPs) are molecular chaperoning and cellular repair. There is little literature on the association between the numerous functions of HSPs and systemic integrative responses, particularly those controlled by the central nervous system. This chapter focuses on the role played by members of the ...
Sonna Larry A - - 2007
Microarray analysis of gene expression at the level of RNA has generated new insights into the relationship between cellular responses to acute heat shock in vitro, exercise, and exertional heat illness. Here we discuss the systemic physiology of exertional hyperthermia and exertional heat illness, and compare the results of several ...
Siegel Arthur J - - 2007
Exercise-associated hyponatraemia (EAH) is an acute-onset imbalance in the tonicity of extracellular fluids during or after endurance exercise which results in a blood sodium concentration <135 mmol/L. Both excessive fluid intake and a concurrent decrease in urine formation contribute to this rapid-onset, predominantly dilutional, decrease in serum sodium, which can ...
Meyer F - - 2007
The dependence of sweat composition and acidity on sweating rate (SR) suggests that the lower SR in children compared to adults may be accompanied by a higher level of sweat lactate (Lac-) and ammonia (NH3) and a lower sweat pH. Four groups (15 girls, 18 boys, 8 women, 8 men) ...
Wendt Daniël - - 2007
As a result of the inefficiency of metabolic transfer, >75% of the energy that is generated by skeletal muscle substrate oxidation is liberated as heat. During exercise, several powerful physiological mechanisms of heat loss are activated to prevent an excessive rise in body core temperature. However, a hot and humid ...
Maughan Ron J - - 2007
The marathon poses a considerable physical challenge for athletes of all levels. When combined with high heat and humidity, not only is performance potentially compromised, but health and well-being are also at risk. There are well recognised effects of heat and hydration status on the cardiovascular and thermoregulatory systems that ...
Kenefick Robert W - - 2007
This article reviews causes of marathon collapse related to physical exhaustion, heat exhaustion and dehydration. During severe exercise-heat stress (high skin and core temperatures), cardiac output can decrease below levels observed during exercise in temperate conditions. This reduced cardiac output and vasodilated skin and muscle can make it difficult to ...
Huber Roman - - 2007
Hot compresses on the right upper abdomen are used as support for patients with liver diseases in Germany. The study was designed to determine, whether they affect hepatic blood flow. Single dose kinetics of indocyanine green (ICG) were studied in 13 healthy subjects with or without hot compresses on the ...
Angilletta Michael J MJ - - 2007
Urbanization has caused regional increases in temperature that exceed those measured on a global scale, leading to urban heat islands as much as 12 degrees C hotter than their surroundings. Optimality models predict ectotherms in urban areas should tolerate heat better and cold worse than ectotherms in rural areas. We ...
Tobina Takuro T Graduate School of Education, Hokkaido University, ; Faculty of Sports and Health Science, Fukuoka University , - - 2007
Angiotensin I converting enzyme (ACE) gene Insertion / Deletion (I/D) polymorphism is associated with exercise trainability and exercise induced left ventricular hypertrophy. However, it is unclear whether this polymorphism influences exercise trainability in the elderly, and the electrocardiological alterations by exercise training is unknown among the genotypes. We herein investigated ...
Kenefick Robert W - - 2006
PURPOSE: This study sought to determine the effect of rapid intravenous (IV) versus oral (ORAL) rehydration immediately after dehydration, on cardiovascular, thermoregulatory, and perceptual responses during subsequent exercise in the heat. METHODS: Eight males (21.4 +/- 0.7 yr; 176.2 +/- 1.6 cm; 75.2 +/- 3.7 kg; 63.7 +/- 3.6 mL.kg.min ...
Reilly Thomas - - 2006
PURPOSE OF REVIEW: Exercise causes body temperature to rise and the resulting heat stored becomes a factor limiting exercise performance in hot conditions. Loss of heat by evaporative processes leads to hypohydration which itself can eventually impair performance. This review focuses on thermoregulatory and behavioural processes during sustained exercise in ...
Taylor Nigel A S - - 2006
INTRODUCTION: Little is known regarding local differences in foot sweat secretion. Since such information is important to our understanding of sweat gland control for thermoregulatory modeling and for the design of footwear we explored this topic. METHODS: Local sweat rates were investigated across core temperatures from 37-39 degrees C, achieved ...
Yoshida Tetsuya - - 2006
To clarify whether the resting background effects (genomic) or exercise-related action (non-genomic) of aldosterone (ALD) is primarily affected to an individual variation in the sweat Na+ concentration ([Na+]sweat), we analyzed the cross-sectional relationship between [Na+]sweat and the plasma ALD concentration during rest and exercise in a hot environment. Eleven college-aged ...
O'Connor Robert E - - 2006
Exercise-induced hyponatremia is most commonly associated with prolonged exertion during sustained, high-intensity endurance activities such as marathons or triathlons. In most cases, exercise-induced hyponatremia is attributable to excess free water intake, which fails to replete the sometimes massive sodium losses that result from sweating. The risk of hyponatremia can be ...
Leite Laura H R - - 2006
The effect of central angiotensin AT1-receptor blockade on thermoregulation in rats during exercise on a treadmill (18 m/min, 5% inclination) was investigated. Core (Tb) and skin tail temperatures were measured in rats while they were exercising until fatigue after injection of 2 microl of losartan (Los; 20 nmol, n = ...
Carter Robert R - - 2006
Hypohydration is associated with orthostatic intolerance; however, little is known about cerebrovascular mechanisms responsible. This study examined whether hypohydration reduces cerebral blood flow velocity (CBFV) in response to an orthostatic challenge. Eight subjects completed four orthostatic challenges (temperate conditions) twice before (Pre-EU and Pre-Hyp) and following recovery from passive heat ...
Kanu Abu B - - 2006
Studies with a new technique, active membrane-differential mobility spectrometry, with aqueous standards of benzene and phenol are described. The atmospheric pressure photo-ionisation chemistries of benzene and phenol in the presence of oxygen are similar in that benzene forms phenol radicals that subsequently react to yield diphenylether and 4-phenoxyphenol products. Further ...
Mendez-Villanueva Alberto - - 2006
The activity profile of men's competitive surfing was investigated during an international contest. Forty-two male surfers were filmed during 42 elimination heats. Surfers' activities were classified into 1 of 4 distinct categories (paddling, wave riding, stationary, and miscellaneous). The surfers were paddling and stationary 51% (25-70%) and 42% (23-72%) of ...
Kalkowsky Bernhard - - 2006
As the percentage of shifts in hot working conditions in German Coal mines had increased to more than 50% during the last decade, a study was carried out to record the physiological strain of miners. Thirty-eight miners participated during 125 shifts. Heart rate and rectal temperature were measured continuously. Sweat ...
Rozsasi Ajnacska - - 2006
BACKGROUND: The aim of this study was to evaluate changes in total respiratory heat loss during use of a heat and moisture exchanger (HME) in tracheotomized patients. METHODS: Tracheal humidity and temperature were measured before the application and during use of the HME (plastic foam impregnated with CaCl2), and total ...
Fanghänel Jörg - - 2006
A new calorimetric method has been developed to follow the time course of slow conformational changes during the refolding of denatured proteins. The method is based on the ability of isothermal titration calorimeters (ITC) to detect small amounts of heat continuously over a minute to an hour time range without ...
Kamijo Yoshi-ichiro - - 2006
The purposes of this review are to show pathophysiological mechanisms for heat illness during working in a hot environment and accordingly provide some preventive considerations from a viewpoint of body fluid homeostasis. The incidence of the heat illness is closely associated with body temperature regulation, which is much affected by ...
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