| No Effect of Moderate Hypohydration or Hyperthermia on Anaerobic Exercise Performance |
2006 |
6 pages |
| Authors:
S. N. Cheuvront; R. Carter; E. M. Haymes; M. N. Sawka; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
 | Purpose: This study examined the effects of hypohydration and moderate hyperthermia (core temperature elevation) on anaerobic exercise performance in a temperate environment. Methods: Eight active males completed two passive heat exposure trials (180-min, 45 degrees C, 50%rh) with (EUH) and without (HYP) fluid replacement. A single 15-s Wingate Anaerobic Test (WAnT) was used to assess anaerobic performance (peak power, mean power, and fatigue index) before (-180-min) and again a three ... |
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| Effect of Moderate Hypothermia on Gene Expression by THP-1 Cells: A DNA Microarray Study |
2006 |
10 pages |
| Authors:
Larry A. Sonna; Matthew M. Kuhlmeier; Heather C. Center; Jeffrey D. Hasday; Craig M. Lilly; Karen D. Fairchild; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| The mechanisms by which moderate hypothermia (32 degree C for 12-72 h) affect human cellular function are unclear. We tested the hypothesis that it produces broad changes in mRNA expression in vitro. Acute monocytic leukemia (THP- 1) cells were incubated under control conditions (37 degrees C) or moderate hypothermia (32 degrees C) for 24 h. RNA was extracted, and the hypothermic response was confirmed by examining the expression of the ... |
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| Heat Related Illnesses |
2006 |
9 pages |
| Authors:
R. Carter; S. N. Cheuvront; M. N. Sawka; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Heat illnesses range in severity form mild (heat rash, heat syncope, cramps) to serious (heat exhaustion, heat injury, heat stroke). Although heat illness can occur in anyone, an increased risk is associated with a variety of environmental factors, personal characteristics, health conditions, and medications. The risk of serious heat illness can be markedly reduced by implementing a variety of countermeasures, including becoming acclimated to the heat, managing heat stress exposure, ... |
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| Rapid IV Versus Oral Rehydration: Responses to Subsequent Exercise Heat Stress |
2006 |
8 pages |
| Authors:
Robert W. Kenefick; Kathleen M. O'Moore; Nicholas V. Mahood; John W. Castellani; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| 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. |
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| Prevention of Cold Injuries During Exercise |
2006 |
19 pages |
| Authors:
J. W. Castellani; A. J. Young; M. B. Ducharme; G. G. Giesbrecht; E. Glickman; R. E. Sallis; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| In is the position of the American College of Sports Medicine that exercise can be performed safely in most cold-weather environments without incurring cold-weather injuries. The key to prevention is use of a comprehensive risk management strategy that: a) identifies/assesses the cold hazard; b) identifies/assesses contributing factors for cold-weather injuries; c) develops controls to mitigate cold stress/strain; d) implements controls into formal plans; and e) utilizes administrative oversight to ensure ... |
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| Effect of Acetazolamide on Leg Endurance Exercise at Sea Level and Simulated Altitude |
2006 |
11 pages |
| Authors:
Charles S. Fulco; Steven R. Muza; Dan Ditzler; Eric Lammi; Steven F. Lewis; Allen Cymerman; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Acetazolamide can be taken at sea level to prevent acute mountain sickness during subsequent altitude exposure. Acetazolamide causes metabolic acidosis at sea level and altitude, and increase Sao2 (arterial oxygen saturation) at altitude. The aim of the present study was to determine whether acetazolamide impairs muscle endurance at sea level but not simulated altitude (4300 m for |
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| Carbohydrate Supplementation and Endurance Performance of Moderate Altitude Residents at 4300 m |
2006 |
8 pages |
| Authors:
C. S. Fulco; M. Zupan; S. R. Muza; P. B. Rock; K. Kambis; T. Payn; M. Hannon; E. Glickman; A. Cymerman; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Recent work from our laboratory demonstrated that carbohydrate supplementation (CHOS) during exercise improved prolonged time-trial (TT) performance of sea-level residents (SLR) living at 4300 m while they were in daily negative energy balance (-1250 kcal/day). The purposes of the current study were to determine during initial exposure to 4300 m: 1) whether CHOS also improves TT performance of moderate altitude residents (MAR) who are in energy balance and 2) if ... |
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| Thermal Stress and the Physiological Response to Environmental Toxicants |
DEC 2005 |
|
| Authors:
Christopher J. Gordon; Lisa R. Leon; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
 | Most toxicological and pharmacological studies are performed in laboratory animals maintained under comfortable environmental conditions. Yet, the exposure to environmental toxicants as well as to many drugs can occur under stressful environmental conditions during rest or while exercising. The intake and biological efficacy of many toxicants is exacerbated by exposure to heat stress, which can occur in several ways. The increase in pulmonary ventilation during exposure to hot environments results ... |
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| Saccadic Velocity and Pupillary Reflexes During Acclimatization to Altitude (4300m) |
JUL 2005 |
9 pages |
| Authors:
A. Cymerman; S. R. Muza; A. L. Friedlander; C. S. Fulco; P. B. Rock; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Oculometrics have been shown to be responsive to hypoxemia. We investigated whether oculometrics could be used as an objective index of a hypoxic effect on the central nervous system (CNS) and altitude acclimatization. We hypothesized that oculomotor reflexes (pupil diameter (PD), constriction amplitude (CA), constriction latency (CL), and saccadic velocity (SV)) changed in concert with a select number of accepted acclimatization variables and that these changes correlated with the severity ... |
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| Human Water Needs |
JUN 2005 |
11 pages |
| Authors:
Michael N. Sawka; Samuel N. Cheuvront; Robert Carter III; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Healthy humans regulate daily water balance remarkably well across their lifespan despite changes in biological development and exposure to stressors or hydration status. Acute or chronic body water deficits result when intakes are reduced or losses increase, but day-to-day hydration is generally well maintained so long as food and fluid are readily available. Total water intake incluces drinking water, water in beverages, and water in food. Daily water needs determined ... |
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| Prevention and Management of Cold-Weather Injuries |
APR 2005 |
95 pages |
| Authors:
J. W. Castellani; C. O'brien; M. N. Sawka; W. B. Gamble; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Soldiers participating in military deployments often encounter cold Stress that requires management for successful mission accomplishment. Excessive cold stress degrades physical performance capabilities, significantly impacts morale, and eventually causes cold casualties. Cold stress environments include not only exposure to extremely low temperatures, but also cold-wet exposures in warmer ambient temperatures. The purpose of this bulletin is to provide guidance to military and civilian health care providers, allied medical personnel, and ... |
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| Oculomotor and Pupillary Reflexes During Acclimatization to Altitude (4300 m) |
JAN 2005 |
26 pages |
| Authors:
Allen Cymerman; Anne L. Friedlander; Stephen R. Muza; Todd A. Hagobian; Andrew W. Subudhi; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| To identify soldiers with a possible health risk when deployed rapidly to moderate altitude, oculometrics were investigated as an objective index of the hypoxic effect on the CNS. The authors previously described the effects of a 4-hour exposure to real and simulated 4,300 m altitude on the pupillary light reflex as measured by the initial pupil diameter (PD), constriction amplitude (CA), and constriction latency (CL). Saccadic Velocity (SV) was measured ... |
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| Physiological Data Acquisition System Documentation |
JAN 2005 |
27 pages |
| Authors:
S. B. Robinson; L. Elliott; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| This report describes a data acquisition system developed to obtain electrocardiogram (ECU), pulse waveform core and skin temperature measurements, as well as ambient climatic conditions. These data are typical of those collected during heat-strain studies in climatic chambers in USARfEM. Since acceptable commercial systems are not available, this system was custom-built to acquire data using National Instruments hardware components and LabVIEW 7.0 Express Developmental Software. General requirements for this system ... |
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| The Use of Gene Knockout Mice in Thermoregulation Studies |
JAN 2005 |
17 pages |
| Authors:
Lisa R. Leon; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| As the use of gene knockout models in thermoregulation studies has gained popularity, the reported incidence of redundant or discrepant phenotypes between studies has also increased, Several gene knockout models mimic human processes and have provided valuable insight into the role of endogenous mediators in thermoregulatory processes. There are also many examples of mutant strains expressing virtually identical phenotypes as their wild-type controls, causing concern regarding the appropriateness of these ... |
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| Environmental Factors for Exercise Testing and Exercise Prescription |
JAN 2005 |
25 pages |
| Authors:
S. N. Cheuvront; M. N. Sawka; K. B. Pandolf; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| The clinical use of exercise testing to evaluate an individual's cardiorespiratory reserve and to enable the appropriate prescription of aerobic activity has attained wide medical acceptance. The physiologic stress from the metabolic intensity imposed by exercise, however, is only one consideration in testing and prescription. An equally important stress is that imposed by the environment (heat, cold, altitude, and air quality). Both exercise and environment alter the physiologic responses of ... |
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| Heat Stress Induces a Biphasic Thermoregulatory Response in Mice |
2005 |
9 pages |
| Authors:
Lisa R. Leon; David A. DuBose; Clifford W. Mason; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Previous animal models of heat stress have been compromised by methodologies such as restraint and anesthesia that confound our understanding of the core temperature (Tc) responses elicited by heat stress. Using biotelemetry, we developed a heat stress model to examine. Tc responses in conscious unrestrained C57BL/6J male mice. Prior to heat stress acclimated > 4 weeks to Ta of 25oC. Mice were exposed to ambient temperature (Ta) of 39.5+/- 0. ... |
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| The Influence of Hydration Status on Heat Rate Variability After Exercise Heat Stress |
2005 |
9 pages |
| Authors:
111 Carter Robert; Cheuvronta Samuel N.; D. W. Wray; Margaret A. Kolka; Lou A. Stephensona; Michael N. Sawka; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| While exercise heat stress and hydration status are known to independently influence heart rate variability (HRV), the combined effect of these physiological stressors is unknown. Thus, heat-acclimated subjects (t = 5) performed exercise heat trials (40 deg C, 20% relative humidity) in the euhydrated and hypohydrated state (3.9 + or - O.7% body weight loss). During each trial, cardiac cycle R-R interval data were collected for 45 min at rest ... |
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| Running Performance Differences Between Men and Women (An Update) |
2005 |
9 pages |
| Authors:
C. N. Cheuvront; R. Carter; K. C. DeRuisseau; R. J. Moffatt; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| More than a decade ago it was reported in the journal Nature that the slope of improvement in the men's and women's running records, extrapolated from mean running velocity plotted against historical time, would eventually result in a performance intersection of the sexes across a variety of running distances. The first of these intersections was to occur for 42,000m before the 21st century. Most of the error in this prediction ... |
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| Epidemiology of Hospitalizations and Deaths from Heat Illness in Soldiers |
2005 |
8 pages |
| Authors:
Robert Carter III; Samuel N. Cheuvront; Jeffrey O. Williams; Margaret A. Kolka; Lou A. Stephenson; Michael N. Sawka; Paul J. Amoroso; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Serious heat illness has received considerable recent attention due to catastrophic heat waves in the United States and Europe, the deaths of high-profile athletes, and military deployments. This study documents heat illness hospitalizations and deaths for the U.S. Army from 1980 through 2002. Hospitalization data were obtained from the Total Army Injury Health Outcomes Database (TAIHOD) coded according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). North ... |
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| Residence at Moderate Altitude Improves Ventilatory Response to High Altitude |
DEC 2004 |
8 pages |
| Authors:
S. R. Muza; P. B. Rock; M. F. Zupan; J. C. Miller; W. R. Thomas; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| This study compared the distribution of arterial oxygen saturation (SaO2) and susceptibility to Acute Mountain Sickness (AMS) in moderate altitude residents (MAR) and low altitude residents (LAR) following rapid ascent to 4056 m. |
|
| Thermal Gradient Data Acquisition System Documentation |
DEC 2004 |
29 pages |
| Authors:
Larry D. Walker; Scott B. Robinson; Lisa Leon; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| This report describes a data acquisition system developed to obtain position and temperature measurements from a mouse thermal gradient following heat exposure or any other thermoregulatory event that can be recorded in mice. Since acceptable commercial systems are not available, this system was custom- built to acquire data using National Instruments' versatile hardware components and LabVIEW 7.0 Express Developmental Software. General requirements for this system are that it be highly ... |
|
| Pool Data Acquisition System Documentation |
AUG 2004 |
35 pages |
| Authors:
Scott B. Robinson; Laurie A. Blanchard; Robert Soares; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| This report describes a data acquisition system developed to obtain body temperature measurements for human volunteers during cold exposure. Since acceptable commercial systems are not available, this system was custom-built to acquire data using National Instruments hardware components and LabVIEW 6.0 Development Software. The system works by integrating signals collected by hardware devices, and the software processes/manipulates by using Virtual Instruments (VI's). This report provides detailed documentation for the construction ... |
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| Effect of Potential Vesicant Antagonist Drugs on White Blood Cell Metabolic Activity in Human Whole Blood Exposed to 2-Chloroethyl Ethyl Sulfide |
JUL 2004 |
13 pages |
| Authors:
David A. DuBose; Michael D. Blaha; David H. Morehouse; Nelya Okun; Craig Hill; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Mustard agent affects several pathways that involve calcium poisoning and protein degradation, but it is not clear how these pathways affect vesicant-induced toxicity. This makes it difficult to develop a good screening test to evaluate chemicals which might be used to antagonize or mitigate mustard's actions in cells. We examined here a screening test that uses live human tissue (human whole blood) and describe how monitoring the tissue after exposure ... |
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| Conversion of a Large Animal Inhalational Anesthesia Machine to One for Small Animal Use |
MAY 2004 |
19 pages |
| Authors:
Lisa R. Leon; Michael D. Blaha; David A. DuBose; Larry D. Walker; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| The use of injectable anesthesia in animal research practices has the disadvantage of uncontrollable anesthesia depth, which leads to toxicity and at times death. This adversely influences research and, animal care and welfare. Injectable anesthesia is generally employed in small research animals, since body mass issues prevent the use of conventional inhalation anesthesia machines, while specialized small animal devices are too costly. To support small animal research in mice and ... |
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| Going Against the Grain: Flaws in the Zone Diet |
APR 2004 |
5 pages |
| Authors:
S. N. Cheuvront; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| The Zone Diet is an eating plan claiming to maintain an "ideal" hormone balance and improve health through the manipulation of dietary carbohydrate and protein. While popular, the diet's health claims are based on dubious information, misinterpreted scientific facts, and it ultimately remains unsubstantiated. |
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| Hypohydration Effects on Thermoregulation During Moderate Exercise in the Cold |
26 MAR 2004 |
7 pages |
| Authors:
R. W. Kenefick; N. V. Mahood; M. P. Hazzard; T. J. Quinn; J. W. Castellani; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Abstract Hyperosmotic hypovolemia impairs vasoconstriction during sedentary cold exposure. The purpose of this study was to determine whether hypohydration alters thermoregulation and cardiovascular responses to exercise in cold air. On four occasions, eight males {35.I (2.7) years, 175.5 (3.1) cm 73.3 (2.6) kg, 57.2 (2.6) ml. kg-1 min-' maximal oxygen uptake( VO2max), 19.6 (2.4)% fat] walked, in t--shirt, shorts, and shoes, at 50% V0Z,nax, for 60 min in either a ... |
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| Altitude Acclimatization Guide |
MAR 2004 |
18 pages |
| Authors:
Stephen R. Muza; Charles S. Fulco; Allen Cymerman; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Rapid ascent of low altitude residents to altitudes above 6,000 ft (1,600 m) increases individual susceptibility to altitude illness and decreases physical and cognitive work performance. Altitude acclimatization allows Soldiers to decrease their susceptibility to altitude illness and optimize physical and cognitive performances for the altitude to which they are acclimatized. Altitude acclimatization consists of physiological adaptations that develop in a time-dependent manner during continuous or repeated intermittent exposure to ... |
|
| Exertional Heat Injury and Gene Expression Changes: A DNA Microarray Analysis Study |
20 FEB 2004 |
12 pages |
| Authors:
Larry A. Sonna; C. B. Wenger; Scott Flinn; Holly K. Sheldon; Michael N. Sawka; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| This study examined gene expression changes associated with exertional heat injury (EHI) in vivo and compared these changes to in vitro heat shock responses previously reported by our laboratory. Peripheral blood mononuclear cell (PBMC) RNA was obtained from four malc Marine recruits (ages 17-19 yr) who presented with symptoms consistent with EHI, core temperatures ranging from 39.3 to 42.5 deg C, and elevations in serum enzymes such as creatine kinase. ... |
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| Operator Functional State Assessment (l'evaluation de i'aptitude operationnelle de i'operateur humain) |
FEB 2004 |
8 pages |
| Authors:
R. Carter; S. N. Cheuvront; M. N. Sawka; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Adequate hydration is essential for maintaining fighting effectiveness, and several common operational stresses can result in relatively large alterations in TBW content and distribution. During most "normal" conditions, humans have little trouble maintaining optimal fluid balance. However, many factors such as sickness, physical exercise, climatic exposure (heat, cold, and altitude), and psychological strain can lead to significant disturbances in water balance (Sawka, 1988). Perhaps the best example involves heat stress ... |
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| Biotelemetry Transmitter Implantation in Rodents: Impact on Growth and Circadian Rhythms |
15 JAN 2004 |
9 pages |
| Authors:
Lisa R. Leon; Larry D. Walker; David A. DuBose; Lou A. Stephenson; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| The implantation of a biotelemetry transmitter for core body temperature (Tc) and motor activity (MA) measurements is hypothesized to have effects on growth and circadian rhythmicity depending on animal body-to- transmitter (B:T) size ratio. This study examined the impact of transmitter implantation (TM) on body weight., food intake (FI), water intake (WI). and circadian Tc and MA rhythms in mice (23.8 +/- 0.04 g) and rats (311.5 +/- 5.1 g) ... |
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| Intermittent Altitude Exposures Reduce Acute Mountain Sickness at 4300 M |
JAN 2004 |
9 pages |
| Authors:
Beth A. Beidleman; Stephen R. Muza; Charles S. Fulco; Allen Cymerman; Dan Ditzler; Dean Stulz; Janet E. Staab; Gary S. Skrinar; Steven F. Lewis; Michael N. Sawka; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Acute mountain sickness (AMS) commonly occurs at altitudes exceeding 2000-2500 m and usually resolves after acclimatization induced by a few days of chronic residence at the same altitude. Increased ventilation and diuresis may contribute to the reduction in AMS with altitude acclimatization. The aim of the present study was to examine the effects of intermittent altitude exposures (IAE), in combination with rest and exercise training, on the incidence and severity ... |
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| Heart Rate Variability as an Index of Physiological Strain in Hyperthermic and Dehydrated Rats |
2004 |
10 pages |
| Authors:
Candance B. Matthew; Amy M. Bastille; Richard R. Gonzalez; Ingrid V. Sils; Reed W. Hoyt; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Telemetry-equipped rats were subjected to hyperthermia (H, T sub c) = 41.5 deg C) with and without dehydration (D 9% loss of body weight) stresses. Time domain and spectral analysis of heart rate variability indicated that the dehydrated hyperthermic (DH) rats had increased sympathetic activity compared to H rats, and DH rats had decreased discriminated the more physiologically stressful of these states. These non-invasive measures of physiological strain discriminated the ... |
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| Hydration Status Monitoring |
2004 |
12 pages |
| Authors:
R. Carter; S. N. Cheuvront; M. A. Kolka; M. N. Swaka; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| This paper reviews widely used indices of hydration status in humans. For the purposes of this review, euhydration will refer to "normal" total body water (TBW), whereas hypohydration will refer to a body water deficit. The term dehydration will be used to refer to the dynamic process of body water loss(i.e., the transaction from euhydration to hypohydration). Greenleaf and Sargent, 1965; Sawka, 1992). The term hypovolemia will define when blood ... |
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| Cold Air Data Acquisition System Documentation |
SEP 2003 |
34 pages |
| Authors:
Scott B. Robinson; Laurie A. Blanchard; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| This report describes a data acquisition system developed to obtain body temperature measurements for human volunteers during cold air exposure. Since acceptable commercial systems are not available, we had to custom-build this system to acquire data using National Instruments hardware components and LabVlEW 6.0 Developmental Software. This report provides detailed documentation for the construction and operation of the cold air data acquisition system. This report lends to the reader insight ... |
|
| Effect of Nifedipine on Core Cooling in Rats during Tail Cold Water Immersion |
SEP 2003 |
5 pages |
| Authors:
Michael J. Durkot; Lawrence de Garavilla; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Male rats (450 g, n=11/group) were heated at an ambient temperature of 42 degrees C until a rectal temperature of 42.8 degrees C was attained. The rats then received either saline (30 degrees C) + tail ice water immersion (F + I) or saline (30 degrees C) + tail ice water immersion + Nifedipine, a peripheral vasodilator (F + I + N) to determine cooling rate effectiveness and survivability. The ... |
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| An Exercise Model to Study Progressive Muscle Fatigue During Constant Work Rate Exercise on a Cycle Ergometer |
JUL 2003 |
39 pages |
| Authors:
Charles S. Fulco; Paolo Bonato; Don Gilmore; Steven F. Lewis; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| To gain insight into mechanisms of muscle fatigue in common everyday activities such as bicycling and running, those muscles which limit performance should be studied by tracking the fatiguability of the same muscles during the activity. However, conventional ergometric testing modes such as stationary cycling or treadmill exercise do not readily lend themselves to quantitating the progressive increase in muscle fatigue, characterized by a loss of muscle power. It has ... |
|
| Environmental Medicine Genome Bank (EMGB): Annual Report and Project Summary |
JUL 2003 |
22 pages |
| Authors:
Nicholas J. Messinese; Craig M Lilly; Larry A. Sonna; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| The Environmental Medicine Genome Bank (EMGB) project is an ongoing effort to identify and characterize genes relevant to environmental illnesses and to human physical performance. To accomplish this, the EMGB banks DNA samples from human volunteers who have participated in environmental and human performance studies or material obtained under approved Brigham and Women's Hospital protocols that would otherwise have been discarded. The EMGB maintains a registry of this phenotypic information. ... |
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| Influence of Moderate Altitude Residence on Arterial Oxygen Saturation at Higher Altitudes |
01 MAY 2003 |
28 pages |
| Authors:
Stephen R. Muza; Paul B. Rock; Michael Zupan; James Miller; William R. Thomas; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Mountainous terrain provides sanctuary for hostile forces as seen in Central and West Asia, the Balkans, and South America. This harsh environment lessens U.S. military technological superiority by limiting use of air support and crew-served combat vehicles. This places the burden of combat on dismounted warfighters. Objective Force Warrior (OFW) emphasizes the rapid deployment and mobility of troops to conduct operations for sustained periods without relief. However, rapid deployment of ... |
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| Flunarizine Attenuates Hypothermia/Rewarming-Induced Changes in Protein and Water Movement Across the Endothelium of Rats |
MAY 2003 |
24 pages |
| Authors:
Candace B. Matthew; Ingrid V. Sils; Amy M. Bastille; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Severe hypothermia damages endothelial cell cytoskeleton and significantly reduces tissue perfusion that is only partially restored on rewarming. The calcium channel blocker flunarizine (FL) was administered to examine the mechanisms and possible attenuation of hypothermia-induced changes in extravasation and perfusion. Blood and tissue samples were taken from 6 groups of 12 male rats: CN (control, normothermic). FLN (N rats given 1 mg/kg of FL by gavage), CHypo and FLHypo (cooled ... |
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| Endurance Time in the Self-Contained Toxic Environment Protective Outfit (STEPO) with Personal Ice-Cooled Microclimate Cooling System (PICS) in Three Environments |
MAY 2003 |
39 pages |
| Authors:
Leslie Levine; Bruce S. Cadarette; Margaret A. Kolka; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| This study of the Self-Contained Toxic Environment Protective Ouffit (STEPO) with the Personal Ice-Cooled Microclimate Cooling System (PICS) in three environments was conducted in September 2002 at the request of Project Manager - Soldier Systems, Product Manager- Soldier Equipment (PM-Soldier), Ft. Belvoir, VA. PM-Soldier was addressing the needs of the STEPO/PICS users for guidance on work times up to 4 hours. A 1999 study of this STEPO/PICS system demonstrated that ... |
|
| Water Immersion and Re-Warming Facility of the Thermal and Mountain Medicine Division |
MAY 2003 |
11 pages |
| Authors:
V. Forte; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| The water immersion laboratory (WIL) simulates cold and hot environments by changing the water temperature in a concrete vessel through a steam-driven heat exchanger and ethylene glycol-jacketed chiller. The desired temperature is precisely manipulated and controlled by pneumatic control values, which receive signals from transducers, and display temperature outputs for each sensor on the digital indicators at the control panel. The temperature is changed to desired protocol conditions for evaluation ... |
|
| Carbohydrate Supplementation Improves Time-Trial Cycle Performance at 4300 m Altitude |
FEB 2003 |
49 pages |
| Authors:
Charles S. Fulco; K. W. Kambis; A. L. Friedlander; P. B. Rock; J. E. Staab; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
|
| Carbohydrate supplementation (CHOS) during prolonged (> 1 hr) heavy cycle exercise at sea level (SL) enhances glucose availability and oxidation, allowing performance at higher work rates compared to control. However, at altitude (ALT), hypoxemia exacerbated by exercise may limit work rate increases and time-trial cycle performance improvements with CHOS. The purpose of this study was to determine if CHOS improves performance at ALT. |
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| Effect of Hypoxia on Gene Expression by Human Hepatocytes (HepG2) |
2003 |
14 pages |
| Authors:
L. A. Sonna; M. L. Cullivan; H. K. Sheldon; R. E. Pratt; C. M. Lilly; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
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| The full extent to which hypoxia produces gene expression changes in human cells is unknown. We used late-generation oligonucleotide arrays to catalog hypoxia-induced changes in gene expression in HepG2 cells. Five paired sets of cultures were subjected to either control (room air-5% CO2) or hypoxic (1% 02-5% CO2) conditions for 24 h, and RNA was analyzed on an Affymetrix cDNA array containing 12,600 sequences. A statistically significant change in expression ... |
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| Environmental Medicine Genome Back (EMGB): Annual Report and Project Summary |
JUL 2002 |
18 pages |
| Authors:
Nicholas J. Messinese; Holly K. Sheldon; Craig M. Lilly; Larry A. Sonna; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
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| The Environmental Medicine Genome Bank (EMGB) project is an ongoing effort to identify and characterize genes relevant to environmental illnesses and to human physical performance. To accomplish this, the EMGB banks DNA samples from human volunteers who have participated in environmental and human performance studies or material obtained under approved Brigham and Women's Hospital protocols that would otherwise have been discarded. The EMGB maintains a registry of this phenotypic information. ... |
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| Cysteinyl Leukotriene Blockade Does Not Prevent Acute Mountain Sickness |
JUL 2002 |
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| Authors:
S. R. Muza; D. Kaminsky; C. S. Fulco; L. E. Banderet; A. Cymerman; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
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| MOUNTAIN sickness (AMS)is a syndrome that is characterized by headache, anorexia, nausea, vomiting, insomnia, lassitude, and malaise. There is individual variation in susceptibility to the syndrome; however, the hypoxia- induced symptoms are most common in unacclimatized low-altitude residents who rapidly ascend to terrestrial elevations exceeding 2,500 m (10). In addition, the development of AMS appears to be promoted by engaging in physical activities at high altitude (7). The symptoms of ... |
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| Effect of Acetazolamide on Isolated Quadriceps Muscle Endurance Performance at Sea Level and During Acute Altitude Exposure |
FEB 2002 |
33 pages |
| Authors:
Charles S. Fulco; Dan Ditzler; Robert Soares; Eric Lammi; Steven R. Muza; David W. Degroot; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
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| Acetazolarnide (AZ) can be taken at sea level (SL) to prevent acute mountain sickness during subsequent altitude (ALT) exposure. AZ causes metabolic acidosis at SL and ALT, and increases arterial oxygen saturation (SaO2) at ALT. HYPOTHESIS: AZ will impair muscle endurance at SL but not ALT (4300 m, <3 h). METHODS: Six subjects (2012 yr; Xl SD) performed exhaustive constant work rate 1-leg knee extension exercise (2512 watts) once per ... |
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| Physiological Response to Cold Exposure in Men: A Disabled Submarine Study |
2002 |
16 pages |
| Authors:
J. W. Castellani; C. O'Brien; D. A. Stulz; L.A. Blanchard; D. W. Degroot; M. E. Bovill; T. J. Francis; A. J. Young; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
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| A disabled submarine (DISSUB) lacking power and/or environmental control will become cold, and the ambient air may become hypercapuic and hypoxic. This study examined if the combination of hypoxia, hypercapnia, and cold exposure would adversely affect thermoregulatory responses to acute cold exposure in survivors awaiting rescue. Seven male submariners (33 plus or minus 6 yrs) completed a series of cold-air tests (CAT) that consisted of 20-min at T(air) = 22 ... |
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| Exercise, genetics, and blood pressure: Focus on "Physical Exercise and Blood Pressure With Reference to the Angiotensinogen M285T Polymorphism" and on "Angiotensinogen M235T Polymorphism Associates With Exercise Hemodynamics in Postmenopausal Women" |
2002 |
4 pages |
| Authors:
Larry A. Sonna; Susan B. Glueck; Xavier Jeunemaitre; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
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| Blood pressure is a complex trait that is influenced by a number of hereditary, environmental, and culturally transmissible factors. Genetic factors are estimated to account for about 30% of the variance in blood pressure in adult populations, and it appears likely that this hereditary contribution is polygenic in nature. Furthermore, there is evidence that the genetic factors contributing to resting blood pressure also affect blood pressure during exercise. |
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| Think Layers When Dressing for Exercise in the Cold |
OCT 2001 |
2 pages |
| Authors:
Catherine O'Brien; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
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| Whether or not you get cold during outdoor activities depends on certain factors including environmental conditions, how much heat your body produces, and whether your body conserves or loses that heat. Humans have two primary physiological responses to cold: vasoconstriction and shivering. Vasoconstriction decreases blood flow to the skin, reducing the rate of heat loss. Shivering increases body beat production. Although these mechanisms maintain body temperature during brief, mild cold ... |
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| Environmental Medicine Genome Bank (EMGB): Current Composition |
SEP 2001 |
20 pages |
| Authors:
Nicholas J. Messinese; Holly K. Sheldon; Craig M. Lilly; Larry A. Sonna; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
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| The Environmental Medicine Genome Bank (EMGB) project is an ongoing effort to identify and characterize genes relevant to environmental illnesses and to human physical performance. To accomplish this, the EMGB banks DNA samples from human volunteers who have participated in environmental and human performance studies or material obtained under approved Brigham and Women's Hospital protocols that would otherwise have been discarded. The EMGB maintains a registry of this phenotypic information. ... |
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