30 Clinical Trials for Various Conditions
The purpose of this study is to determine if, compared to non-depressed adults, differences exist in skin blood flow and sweating responses to passive heat stress in adults with clinically diagnosed depression, those with depression who are prescribed and taking SSRIs and those with depression who are prescribed and taking SNRIs.
The frequency and severity of heat waves has increased in the last decades. Older adults (over 65 years) have impaired responses to heat stress making them at increased risk for adverse events. Previous heat waves report that women over 65 experience worse health outcomes than any other age group and age matched men. Aging and reproductive hormones, specifically estrogen, independently alter responses to heat stress. However, the combined effects of low estrogen following menopause and aging on the response to heat stress are unknown. In this study, the investigators will identify the role of estrogen in pre and post menopausal women on thermoregulatory responses to heat stress.
The goal of this project is to understand the factors that affect skin temperature (e.g., tissue above amputation site, and opposite foot) in people with amputation and diabetes. This project will also test the effects of 'shock-absorbing' prosthesis on skin temperature responses.
This will be a double blind, placebo-controlled, randomized, counterbalanced, crossover study designed to assess the impact of preloaded betaine supplementation on thermoregulation and exercise metabolism in the heat. The study, outlined in Figure 7 and described in detail below, will consist of seven total visits to the Institute of Sports Science and Medicine (ISSM) or Sandels laboratories at Florida State University, two of which will be experimental visits. On the first visit, participants will be informed as to the details of the study before giving their oral and written informed consent (Appendix A). Thereafter, anthropometrics will be measured and participants will complete an incremental exercise test on an electronically-braked cycle ergometer to volitional exhaustion to determine peak oxygen consumption (VO2 peak). Days 1-6 participants will consume a full dosage of supplementation, whereas day 0 and 7 participants will consume half a dose of the supplement, with the last dosage being consumed 60 minutes prior to experimental visits, days 7 and 21. On days 2 and 4, familiarization trials will be completed to standardize training loads and to reduce any potential learning effect. These visits will be implemented in the heat. On day 7, participants will complete the first experimental trial described in detail below. Afterwards, participants will enter a seven day washout period 167 before crossing over to the second supplemental condition on day 14. On days 16 and 18, participants will undergo the same familiarization trials as they did on days 2 and 4. On day 21, participants will complete their second experimental trial. Each experimental trial will be separated by 14 days. This study will be approved by the Florida State University Insitutional Review Board (Appendix B).
The project will evaluate thermoregulatory processes among individuals with and without first-episode psychosis.
To assess and compare the quality of sleep self- reported by veterans with sleep disorders before and after use of the Chilipad cooling mattress pad
This is a double-blinded, randomized, crossover design study to assess the effects of dietary nitrate supplementation (beetroot juice) on peripheral artery disease (PAD) patients (ages 50-85) diagnosed with Fontaine stage I or II PAD (as determined by vascular surgeon at UNMC). Exclusion criteria include: 1) experience severe claudication (leg pain) at rest or tissue loss due to PAD (Fontaine stage III and IV), 2) have limited walking capacity due to conditions other than PAD, 3) are already supplementing with a form of dietary nitrate, or 4) have an allergy to beetroot juice. Subjects will be required to visit the lab 3 times and will be randomized to receive either the supplement or the placebo for the 2nd and 3rd visits. There will be a washout period of 14 days between the 2nd and 3rd visits. Visit 1 will take approximately 2 hours and the 2nd/3rd visits will take approximately 1.5 hours. Total experimentation period will last approximately 15 days. Visit 1 will consist of non-invasive baseline testing including assessment of endothelial function (flow-mediated dilation by ultrasound imaging), maximal walking capacity (Gardner treadmill protocol), leg function (near-infrared spectroscopy, time to onset claudication, blood flow to lower extremities), and body core temperature (rectal thermometer). Visits 2 and 3 will require consumption of either the supplement or placebo. The same tests from the baseline measurements will be performed for visits 2 and 3. There will be a recommended fourth visit, albeit not required, to review study results.
The ability to maintain normal core body temperature (Tcore = 98.6°F) is impaired in persons with a cervical spinal cord injury (tetraplegia). Despite the known deficits in the ability of persons with spinal cord injury (SCI) to maintain Tcore, and the effects of hypothermia to impair mental function in able-bodied (AB) persons, there has been no work to date addressing these issues in persons with tetraplegia. Primary Aim: To determine if exposure of up to 2 hours to cool temperatures (64°F) causes Tcore to decrease in persons with tetraplegia, and if that decrease is associated with a decrease in cognitive function. Primary Hypotheses: Based on our pilot data: (1) 66% of persons with tetraplegia and none of the matched controls will demonstrate a decline of 1.8°F in Tcore; (2) 80% of persons with tetraplegia and 30% of controls will have a decline of at least one T-score in Stroop Interference scores (a measure of executive function). Secondary Aim: To determine the change in: (1) distal skin temperature, (2) metabolic rate, and (3) thermal sensitivity. Secondary Hypothesis: Persons with tetraplegia will have less of a percent change in average distal skin temperatures and metabolic rate, and report lower thermal sensitivity ratings compared with AB controls. Tertiary Aim: To determine if a 10 mg dose of an approved blood pressure-raising medicine (midodrine hydrochloride) will (1) reduce the decrease in Tcore and (2) prevent or delay the decline in cognitive performance in the group with tetraplegia compared to the exact same procedures performed on the day with no medicine (Visit 1) in that same group. Tertiary Hypothesis: Through administering a one-time dose of midodrine, the medicine-induced decreased blood flow to the skin will lessen the decline in Tcore and prevent or delay the associated decline in cognitive performance compared to the changes in Tcore and cognitive performance during cool temperature exposure without midodrine in the same group with tetraplegia.
Total joint patients have poor outcomes with infection since they are having permanent hardware implanted. Infection prevention in this group is therefore critical and a major source of discussion in both the orthopedic and anesthesia literature. Hypothermia has been shown to increase the risk of infection and blood loss. However, studies have not examined when in the operation or how fast patients temperatures drop. This study will observe how patients' temperatures change during total joint arthroplasty. By identifying when body temperature changes occur, prevention strategies may be developed and implemented.
Exertional heat stroke (EHS) affects \~500 Military Personnel and over 100 Soldiers every year, and it is believed that these numbers are underreported. EHS is the most severe form of exertional heat illness (EHI) and can result in substantial, long-lasting organ damage, and even death in severe cases. Based on current knowledge and training needs, it is impossible to prevent every EHS - which shifts the focus from exclusively prevention to a combination of prevention, treatment, and enhancing recovery as much as possible. While many risk factors have been identified and there are adequate treatments available, biomarkers associated with heat stroke risk, recovery, and return-to-duty (RTD) remain largely unclear. The purpose of the proposed study is to enhance knowledge surrounding biomarkers of EHS and long-term health consequences that result from EHS. The investigators will recruit research volunteers for a field study in order to collect pre-, post-, and follow-up measures from a high-risk EHS event (i.e. ruck marches, timed runs) this will allow us to have a basis for comparison between Soldiers who collapse with EHS (from previously collected data) and those that complete high-risk events, but do not collapse. This will allow for comparison between the groups to identify EHS-specific biomarkers that could aid in recovery and RTD decisions for Soldiers.
Acute mirabegron administration has been shown to increase brown fat activity in humans. Long-term mirabegron administration upregulates brown fat, and appears to improve glucose regulation, and change skeletal muscle phenotype.
Carbohydrate ingestion, in particular fructose, has been shown in a handful of previous studies to elicit a thermic effect and increase core body temperature after ingestion. Carbohydrate foods and supplements are commonly consumed prior to endurance running competition, including situations where an athlete's ability to dissipate body heat is compromised. Thus, there is some potential for pre-exercise carbohydrate ingestion to have a deleterious effect on body heat regulation in hot and humid environments. Thus, this projects aims to study the effects of pre-exercise carbohydrate ingestion on core body temperature, perceived thermal stress, and perceived exertion during high-intensity running.
This is a phase I descriptive pilot study to determine the feasibility of using the Heat Retention Head Wrap on infants during the re-warming period following cardio-pulmonary bypass.
The purpose of this study is to examine the need for reflective heat shield covers over the temperature probes applied to the skin of newborn babies who are being nursed under a radiant warmer.
This project will identify the efficacy of cooling modalities aimed to attenuate excessive elevations in skin and internal body temperatures, and associated indices of cardiac stress, during physical activity in well-healed burn survivors. The investigators will conduct a randomized crossover design study. Non-burned control subjects and subjects who experienced burns covering 20% or more of their body surface area will be investigated. Subjects will exercise in heated environmental conditions while receiving no cooling (control) as well as skin wetting.
The earth's climate is warming, and the number of heat waves has increased in recent years. At the same time, the number of adults over the age of 65 is growing. Humans sweat and increase blood flow to the skin to cool their body when they get hot. Older adults do not do this as well as young adults. This makes it harder to safely be in warm and/or humid conditions. It is important to learn about cooling strategies for older adults to safely be in warm and/or humid conditions. There is compelling evidence that intermittent hand and forearm cold-water immersion effectively reduces the rise of core temperature during heat stress in older adults. However, it is still unknown if this is an effective cooling strategy for older adults. Furthermore, our laboratory has shown that folic acid supplementation improves blood flow responses in older adults. This may be beneficial to older adults during heat stress.
The purpose of this study is to investigate thermoregulatory responses in older individuals with COPD.
The goal of this interventional crossover study is to determine the effects of transcutaneous spinal cord stimulation (TSCS) on the ability to perform moderate exercise and regulate core body temperature in the chronic spinal cord injury community. The main questions it aims to answer are: * What are the effects of active TSCS targeted for BP control on exercise endurance time and HR recovery during submaximal arm cycle ergometry (ACE) as compared to sham TSCS in participants with chronic, cervical SCI? * What are the effects of active TSCS on Tcore responses to cool ambient exposure and on subjective reporting of thermal comfort and thermal sensitivity as compared to sham TSCS. Participants will receive sham and active stimulation while using an arm bicycle or while in a cold room. Participants are free to participate in either the exercise phase, the cold room phase, or both phases of this study. Please note that there no expected long term benefits of this study.
Assess the effects of intranasal cocaine on temperature regulation and whole-body sweat rate during exercise in warm environmental conditions.
This study is investigating the efficacy of CORE™ devices in calculating core body temperature in athletes under varying environmental conditions.
This study is intended to calculate the core body temperature in patients who are having a Cesarean Section (C/S) and are kept warm with an Upper Body Forced Air Warming device (Bair Hugger) or underbody forced air warmer. These warming devices are approved and are a required item in many if not all surgical procedures. They are used daily throughout the hospital. The research question is: Where is the best place to position the warming blanket in pregnant mothers undergoing Cesarean section delivery. The researchers hope to compare post - operative core body temperatures in patients getting an Upper Body forced air device versus those getting an Underbody Body forced air warming device.
The investigators hope to learn the feasibility and preliminary efficacy of the Embr device for improving thermal comfort in individuals with POTS and impaired thermoregulation. Feasibility will be assessed via usage of the Embr device and participant feedback. Preliminary efficacy measures will include temperature-related symptoms and temperature- related quality of life in individuals with POTS and impaired thermoregulation.
This project will identify the efficacy of cooling modalities aimed to attenuate excessive elevations in skin and internal body temperatures during physical activity in well-healed burn survivors. The investigators will conduct a randomized crossover design study. Non-burned control subjects, subjects who experienced burns covering \~20% to 40% of their body surface area, and subject having burns \>40% of their body surface area will be investigated. Subjects will exercise in heated environmental conditions while receiving the following cooling modalities: no cooling, fan only, skin wetting only, and a combination of fan and skin wetting.
This study evaluates critical environmental limits (temperature and humidity) above which older adults are unable to effectively thermoregulate. Participants will exercise in a series of different environmental conditions to identify combinations of temperature and humidity above which age-related physiological changes cause uncompensable heat stress, resulting in increased risk of heat illness.
This prospective randomized clinical trial will assess the effect of pre-operative convective warming on intra-operative thermoregulation in patients undergoing gastrointestinal or genitourinary surgical procedures with the Tiger anesthesia perioperative protocol.
Patients under deep sedation and general anesthesia lose heat to their surrounding environment. Hypothermia after anesthesia is associated with worse patient outcomes, including increased number of infections and cardiovascular complications. Cardiac MRI scans performed for patients who require general anesthesia can cause a loss of body heat. Several mechanisms exist for reducing hypothermia under anesthesia including forced air warmers, fluid warmers, radiant warmers, and chemical warmers. Unfortunately, there are no MRI-compatible systems which allow patient warming and prevention of hypothermia in anesthetized patient in the MRI-scanner. This study is testing a non-invasive device that warms patients under clinically indicated general anesthesia in the MRI scanner. This device will keep in the heat made by the MRI scanner.
Background: - The way that the body burns calories is known as energy expenditure. Some studies show that when we are cold, we burn more calories to keep our bodies warm. Brown fat is a special kind of fat that can use energy to keep the body warm. Small animals and infants have been known to have brown fat for many years. Recently, it has been suggested that adult humans also have brown fat. If brown fat becomes active (burns calories) in adult humans when exposed to cold, then these people would tend to burn off more calories and might not gain weight easily. Learning more about the relationship between energy expenditure, brown fat, environmental temperature, and body temperature may help explain why some people become obese and other people do not. Objectives: * To better understand how the body burns calories when exposed to different temperatures. * To study brown fat and how it burns calories in cold temperatures. Eligibility: * Healthy men between 18 and 35 or 55 and 75 years of age. * Healthy women between 18 and 35 years of age. * To control for ethnicity, participants must be non-Hispanic whites or African Americans. Design: * Participants will be screened with a physical exam and medical history. Blood and urine samples will be collected. * Participants will stay in the Metabolic Unit of the National Institutes of Health Clinical Center as inpatients for no more than 14 days. The length of the hospital stay will depend on how participants respond to the different study temperatures. * Every afternoon, participants will walk for 30 minutes on a treadmill. All meals will be provided. * Participants will stay up to 5 hours per day in a specialized room with different temperature settings. Temperatures will range from about 61 degrees to 88 degrees Fahrenheit. Body temperature, activity, calorie burning, and cold/hot sensations will be monitored. On the study day of the coldest temperature, participants will have an imaging study to look for brown fat activity. * Participants will be compensated for their time and participation at the end of the study.
Preterm newborns typically must be thermally regulated. In the United States, isolettes (incubators) are used to help them maintain their temperature. Traditionally, the temperature support (i.e. the temperature of the incubator) is decreased slowly according to NICU protocol until the baby is able to maintain its temperature in an open crib, without regard to the status of its feedings. This study will attempt to determine if there is a difference in length of stay, weight gain, and calories needed to gain appropriate weight between a group of newborns whose isolette temperatures are decreased in an aggressive strategy (isolette temperatures are decreased based only on baby's body temperature), and a group of newborns whose isolette temperatures are decreased in a conservative strategy (isolette temperatures are decreased to a minimum temperature and then kept steady until their feeds are at caloric goal and they are taking at least half of their feeds by mouth).
This study will examine how body metabolism adjusts to small changes in environmental temperature and how it may be related to weight loss. Healthy, non-obese individuals between 18 and 60 years of age may be eligible for this study. The study consists of one screening visit and one 5-day admission to the NIH Clinical Center for the following procedures: Diet: Participants follow a proscribed diet consisting of 50% carbohydrates, 20% protein and 30% fat. DEXA scan to measure body fat. Subjects lie on a table above a source of X-rays while a very small dose of X-rays is passed through the body. Air displacement plethysmography (Bod-Pod) to study fat composition: Subjects sit in a small booth for 10 minutes wearing a swim suit and breathing normally through a tube. This test measures the person s weight and volume precisely. Metabolic room: Subjects stay 12 hours in a specialized room designed to measure the amount of oxygen breathed in and the amount of carbon dioxide breathed out. The room contains a private toilet and sink, treadmill, bed, desk, window, telephone and computer with television and internet access. While in this room, subjects undergo the following: * Continuous heart rate monitor: Subjects wear an EKG monitor to analyze heart rate variability. * Spontaneous movements: Subjects wear portable accelerometers at the hip and wrist to measure spontaneous physical movements. * Continuous temperature monitor: Subjects swallow a small capsule that transmits internal body temperature via miniature, wireless sensors. Adhesive patches placed on the skin monitor external body temperature. * Blood and urine collections: Subjects collect all of their urine during the 12 hours they are in the metabolic room. Blood samples are taken at specified intervals through a catheter that has been placed in a vein. * Microdialysis: A small needle is placed into fat tissue just under the skin on the abdomen. A solution containing a minimal amount of ethanol is infused and samples of fluid are collected every 20 minutes as it leaves the fat pad. This helps determine the metabolism level. This procedure starts 30 minutes before entering the metabolic room and continues until the subject leaves the room. Fat tissue biopsy: A small piece of fat tissue is withdrawn through a needle from under the skin on the abdomen. The sample is used to study fat tissue size and ability to store sugar.
Subjects will walk on a treadmill at 3 mph and sweat will be collected from both forearms. One arm will be pretreated with topical lidocaine, and the other will act as the control.