View clinical trials related to Normal Physiology.
Filter by:Background: Brain activity creates waste products. The body s glymphatic system removes this waste, especially during sleep. One brain waste product is amyloid-beta (Ab). It plays a role in Alzheimer s disease. Researchers want to study the effect of sleep on Ab in the brain. Objective: To see if sleep affects the amount of waste product removed from the brain. Eligibility: Healthy people at least 18 years of age. Design: Participants will be screened with a medical history, physical exam, and blood and urine tests. They will answer questions about drug use, psychiatric history, and family history of alcoholism or drug use. Participants will complete an MRI screening questionnaire. Participants will stay in the clinic overnight two times. On one night they will sleep through the night. On the other night they will be kept awake all night. These overnight visits can happen in any order. Participants will wear 2 activity monitors, on the wrist and the ankle. Participants will have positron emission tomography (PET) scans. A small amount of a radioactive chemical will be injected through an intravenous (IV) catheter. Participants will lie on a bed that slides into the scanner. A cap or a special mask may be placed on the participant s head. Participants will have magnetic resonance imaging (MRI) scans. The MRI scanner is a metal cylinder in a strong magnetic field. Participants will lie on a table that slides into the cylinder. A device called a coil will be placed over the head. Participants will do a task on a computer screen in the scanner. Participants will have tests of thinking, memory, and attention. They may be interviewed, complete questionnaires, take pen-and-paper or computer tests, and perform simple actions.
Background: - The drug filgrastim (rGCSF) increases the number of blood-forming cells in the bloodstream. These cells can be collected from donors bloodstreams and used for transplant. Studies have shown that rGCSF is present in the breast milk of nursing mothers who are taking it. Based on these studies, it is now recommended that a nursing mother should not breastfeed from the time she receives the first dose of the drug until 2 days after the final dose. Researchers want to study the amount of the drug and its effect on the cells present in donor blood and breast milk. They hope to better understand the effects of this drug on breast milk. Objectives: - To understand the effects of filgrastim on breast milk. Eligibility: - Women enrolled in NIH protocol 00-CC-0165 and currently breastfeeding. Design: - Participants will receive rGCSF daily for 5 days. They will have blood taken daily. - Participants will get a freezer bag containing 10 sterile, labeled containers for breast milk collection. - Participants will transfer some of the breast milk they pump into one of the containers. They will write the date and time the milk was collected on the container. They will freeze the samples. Any remaining milk should be disposed of. - Participants will bring the samples to NIH on the day of their stem cell collection procedure. - For days 1 and 2 after stem cell collection, participants will continue to collect and freeze breast milk samples and dispose of any remaining milk. - For days 3 5 after stem cell collection, participants will collect and freeze samples. They can also resume normal breastfeeding. - A research nurse will arrange to collect the samples.
Background: - Magnetic resonance imaging (MRI) is used to investigate brain function. Researchers want to use MRI to better understand the function patterns and connections between brain regions in healthy people. This might help people with brain diseases in the future. Objectives: - To evaluate MRI methods performed twice on the same day. - To evaluate brain function using positron emission tomography (PET). Eligibility: - Healthy volunteers at least 18 years old. Design: - Visit 1: - Participants will be screened with medical history, physical exam, and interview about drug and alcohol use and psychiatric history. - They will give blood and urine samples. Their breath will be tested for alcohol and smoking. - Visit 2: - Participants will have urine collected. They will have MRI scans, some while resting, some while doing tasks on a computer. - The MRI scanner is a metal cylinder in a strong magnetic field. Participants will lie on a table that slides in and out of the cylinder, with a coil over their head. Participants will get earplugs for loud noises. - Visit 3: - Participants will have urine collected. - A needle will guide a thin plastic tube (catheter) into each arm. The needle will be removed, leaving the catheter in the vein. - Participants will then have a PET scan. They will get the chemical 18FDG in the catheter. They will lie on a bed that slides in and out of the PET scanner, with a cap on their head. - Participants may have tests of memory, attention, concentration, and thinking. They may complete interviews, questionnaires, tests on paper or computer, and simple actions. - Participants will wear a device for 1 week between visits to measure activity and sleep.
Background: - One form of the influenza vaccine is a nasal spray. It uses a live but weakened flu virus. Researchers want to better under how the live vaccine interacts with the body s immune system. They will test the nasal spray flu vaccine (called FluMist) against a saline (salt water) nasal spray. They will then look at blood and nasal cell samples to see how the vaccine affects these cells immune response. Objectives: - To look at immune changes in nasal and blood cells in people who receive live flu vaccine. Eligibility: - Healthy volunteers between 18 and 49 years of age. Design: - Participants will have five outpatient visits for this study. Each visit will last up to 2 hours. - At the first visit, participants will have a physical exam and medical history. They will give blood and urine samples. Nasal cell samples will also be collected. - A week later, participants will have either the nasal spray flu vaccine or a saline spray. They will know which spray they will receive. Blood samples will be collected. - Two days after the vaccination, they will have another physical exam. Blood and nasal cell samples will be collected. - At the final two visits (1 week and 1 month after the vaccination), more blood samples will be collected. - Those who had the saline spray will be able to have the actual vaccine spray at the last study visit. - The ratio of participants who receive vaccine to those who receive saline will be 4:1.
Background: - Vaccines and antiviral therapies are critical for preventing and treating viral diseases. Testing these vaccines and drugs often requires healthy volunteers. To ensure that volunteers are healthy and eligible to participate in these studies, they will be screened before the start of the study. This screening may involve a medical history, physical exam, and blood test. Other samples may also be collected. This study will help identify volunteers who are eligible to participate in vaccine or antiviral therapy trials. Objectives: - To screen volunteers for clinical trials of vaccines or drugs to treat or prevent virus infections. Eligibility: - Healthy volunteers at least 18 years of age. Design: - Screening may begin several months before the start of the clinical trial. Participants may come to the National Institutes of Health clinic one or more times. - Participants may be screened with a physical exam and medical history. Blood samples will be collected. Other samples may also be collected, including urine, nasal wash, nasal swab, or stool samples. All samples will be stored for reference by the study researchers....
Background: - Bacteria and other micro-organisms in the intestines play important roles in immunity and other health conditions. As a result, these micro-organisms are likely to affect many health conditions, including several types of cancer. Because cancer and other diseases may affect the digestive system and the bacteria within it, fecal samples that are taken both before and after the onset of a disease may show important changes in the body and provide information about possible treatments. However, unlike repositories of blood and tissue samples, researchers do not have a repository of fecal specimens. Researchers are interested in determining whether standard collection procedures used for fecal occult blood testing can provide accurate information on micro-organisms in the intestine. Objectives: - To determine whether standard fecal occult blood testing procedures can provide accurate collections of fecal micro-organisms for research purposes. Eligibility: - Healthy volunteers at least 18 years of age. Design: - At the clinical center, participants will be provided with written and illustrated instructions for the collection procedures and a self-administered risk questionnaire. The questionnaire will assess the challenges of collecting fecal specimens and will collect data on major dietary restrictions (e.g., vegan, vegetarian, food allergies), medication use and major illnesses, knowledge of and past experience with fecal occult blood testing, colonoscopy and colon cancer, and the fecal collection devices. - Participants will be provided with a collection bag for the sample, 16 sample collection tubes, and a box with frozen gel packs. - On the morning of collection, participants will collect the fecal sample in the bag and use the collection tubes to obtain material from different parts of the stool. - The tubes will be sealed and placed in the box with the gel packs, and the participant will hand deliver the entire box to the clinical center. - Characteristics of the bacteria in the material will be measured by laboratories at the University of Maryland. - Statistical comparisons will determine how well the procedures worked.
Background: - Incidence of breast cancer is very low in Mongolia (6.6/100,000), especially in rural areas. Over the past 15 years, there has been considerable economic growth in Mongolia, resulting in migration to urban centers such as the capital, Ulaanbaatar, from areas with nomadic or semi-nomadic lifestyles. This recent migration offers an opportunity to study the endocrine profiles of premenopausal women as they acculturate to a more Western lifestyle. Objectives: - To obtain new data on premenopausal endocrine and growth factor concentrations to assess possible variations by migration status within Ulaanbaatar; that is, to compare women who have been living in Ulaanbaatar for the longest period of time with those who have recently moved to Ulaanbaatar. - To compare data from Mongolia with data from the United States (and possibly China), where women are at higher risk of breast cancer. Eligibility: - A sample of 375 premenopausal women will be drawn from a larger sample of mothers whose children are participating in a study conducted by Harvard Medical School. Only mothers of girls will be included in this cross-sectional study. Women ages 25 44 years who are not pregnant or breastfeeding are eligible. Design: - A total of 30 ml (three 10 ml samples) of whole blood will be collected. Women will be asked to provide a spot urine sample. These samples will be sent periodically to the NCI biorespository during the course of the study for testing. A portion of a sample for each participant will be kept in Ulaanbaatar in case of problems in delivery to the United States. - The following hormones will be evaluated: testosterone, androstenedione, dehydroepiandrosterone (DHEA), DHEA-sulfate, estrone, estradiol, estriol, progesterone, prolactin, placental lactogen, IGF-1 and IGFBP-3, VEGF, soluble endoglin, and possibly other angiogenic proteins. - Socioeconomic status and medical and lifestyle information will be assessed by questionnaire, including ethnicity, occupation, education, and migration status (e.g., whether she moved from a rural area and time since migration). Breast cancer risk factors such as age at first pregnancy, age at first menstruation, gravidity (total number of pregnancies), parity (total number of childbirths), smoking status, alcohol use, and dietary intake will also be determined. (These questionnaires will have been pilot tested and revised before the start of this study.) The Global Physical Activity Questionnaire, developed by the World Health Organization, will assess physical activity. - Mean and median premenopausal hormone concentrations of previously collected blood samples from women in the United States who are at high breast cancer risk will be compared with the Mongolian samples. In addition, Chinese data will be compared if available.
This study will examine whether genetic differences among individuals affect blood levels of certain chemicals called DBPs after showering. Chemicals such as chlorine and ozone are used to kill germs in water. These chemicals may react with organic matter in the water and form other chemicals called disinfection byproducts, or DBPs. Although people are usually exposed to DBPs by drinking tap water, these chemicals may also penetrate the body during showering. This study will see whether the levels of DBPs after showering vary among individuals depending on differences in genes that code for enzymes called GSTT1, CYP2D6, and CYP2E1, which break down DBPs. This study, sponsored by the Centers for Disease Control and Prevention and the National Institutes of Health, is conducted at the University of Pittsburgh's Center for Clinical Pharmacology. Healthy adults between 18 and 45 years of age who do not smoke cigarettes and are not taking any medicines may be eligible for this study. Candidates are screened with a medical history and blood and urine tests. Participants are given a diary to record the foods they eat and how much water they drink during the 2 days before their study appointment. The following activities are scheduled on the appointment day: - Measurements of blood pressure, height, and weight, and pregnancy test for women - Questions about alcohol consumed and medications taken in the last 48 hours - Review of food and water diary - Interview for demographic information (name, address, date of birth, etc.) and other information, such as sex, height, weight. Subjects are also asked about anything, such as exercise, that might affect their breathing, since breathing problems are a rare side effect of chlorzoxazone, a drug used in this study. - Urine sample collection - Blood draw and insertion of a small catheter (plastic tube) to allow for additional blood draws during the test procedure without having repeated needle sticks - 10-minute shower in a private bathroom - Blood sample collection 10 minutes after the shower and again at 30 minutes after the shower - Dose of chlorzoxazone (a drug used to treat muscle pain) - Interview about subject's exposure to water - Light breakfast - Blood and urine collections 2 hours after the chlorzoxazone dose - Lunch - Observation for drug side effects for 2 hours, or longer if needed Seven blood samples totaling 75 milliliters (about 5 tablespoonfuls) of blood are collected during this study. The blood is tested for chemicals called trihalomethanes to see how they are broken down. The urine samples are tested for chemicals called haloacetic acids, which are found in tap water after it has been treated with chlorine.
Objectives: Plasma levels of catechols have distinct meanings in terms of indicating functions of endogenous catecholamine systems. This Protocol is designed to enable ongoing quality assurance of diagnostic and research assays of catechols and their metabolites and to identify possible influences of demographic and anthropometric factors, dietary constituents, and conditions of sampling on reference values. Study Populations: The study population is healthy volunteers and people who are obese or have untreated hypertension. Design: Arm venous blood is drawn via an indwelling i.v. catheter from healthy volunteers across demographic and anthropometric spectra (age, gender, skin color, ethnicity, body mass, adiposity), to obtain quality control plasma and establish reference values for plasma levels of catechols and their metabolites. Non-invasive physiological measures are obtained concurrently. Levels of catechols and their metabolites are related to results of common clinical pathology tests. Subgroups of subjects are tested more than once, to assess dietary influences (cereal with milk, coffee) and conditions of sampling (temperature at the skin). Outcome Measures: The main non-experimental outcome is an ongoing pool of quality control plasma. The main experimental outcome measures are plasma concentrations of catechols and their metabolites, non-invasive physiological measures, and results of common clinical pathology tests. Subject groups are compared with respect to the above demographic and anthropometric factors. Effects of the experimental manipulations are assessed within subjects