Author Interviews, Brigham & Women's - Harvard, Circadian Rhythm, Diabetes, Occupational Health, Science, Weight Research / 06.12.2021

MedicalResearch.com Interview with: Sarah L. Chellappa, MD PhD Medical Chronobiology Program Division of Sleep and Circadian Disorders Departments of Medicine and Neurology Brigham and Women’s Hospital Division of Sleep Medicine, Harvard Medical School Boston, MA Department of Nuclear Medicine Faculty of Medicine and University Hospital Cologne University of Cologne, Cologne, Germany. Frank A.J.L. Scheer, M.Sc., Ph.D. Professor of Medicine. Medical Chronobiology Program Division of Sleep and Circadian Disorders Departments of Medicine and Neurology Brigham and Women’s Hospital Division of Sleep Medicine, Harvard Medical School Boston, MA MedicalResearch.com: What is the background for this study? Would you explain the difference between the central circadian ‘clock’ and endogenous circadian glucose rhythms?  Response: Night work increases diabetes risk. This increased risk is not fully explained by differences in lifestyle, family history, and/or socioeconomic status, thus other mechanisms are likely involved. Laboratory studies in humans have shown glucose intolerance in both non-shift workers and shift workers exposed to simulated night work. Animal experimental data suggests that this may be in part due to a misalignment between central and peripheral rhythms. Central circadian rhythms (e.g., body temperature) are primarily modulated by the central circadian “clock”, which is located in the brain’s suprachiasmatic nucleus and is responsible for synchronizing our physiology and behavior with the 24-hour cycle. Peripheral rhythms, including endogenous circadian glucose rhythms, are likely modulated by peripheral “clocks” across the body that play an integral role in modulating the circadian expression of physiology, including metabolic functions. These central and peripheral clocks share a common molecular mechanism underlying their circadian rhythm generating capacity, including transcription-translation feedback loops of circadian “clock” genes.  (more…)
Asthma, Author Interviews, Brigham & Women's - Harvard, Circadian Rhythm, Occupational Health, PNAS, Pulmonary Disease, Sleep Disorders / 11.09.2021

MedicalResearch.com Interview with: Frank Scheer, PhD, MSc Professor and Director of the Medical Chronobiology Program Division of Sleep and Circadian Disorders Brigham and Women’s Hospital Steve Shea, PhD Professor and Director Oregon Institute of Occupational Health Sciences MedicalResearch.com: What is the background for this study? Response: For hundreds of years, people have observed that asthma severity often worsens in the nighttime. As many as 75 percent of people with asthma—20 million people in the U.S.—report experiencing worsening asthma severity at night. One longstanding question has been to what degree the body’s internal circadian clock—as opposed to behaviors, such as sleep and physical activities—contributes to worsening of asthma severity. Our research used long term intensive monitoring throughout two circadian protocols in dim light and without time cues to carefully isolate the influence of the circadian system from the other factors that are behavioral and environmental, including sleep. (more…)
Alzheimer's - Dementia, Author Interviews, Circadian Rhythm, JAMA / 30.01.2018

MedicalResearch.com Interview with: “mirror clock” by tourist_on_earth is licensed under CC BY 2.0Yo-El Ju, MD Assistant Professor of Neurology Sleep Medicine Section Washington University School of Medicine MedicalResearch.com: What is the background for this study? What are the main findings? Response: The background for this study is that prior studies have shown that people with Alzheimer's Disease have poor circadian clock function, for example sleeping during the day and being awake or agitated at night. Autopsy studies have shown that people with Alzheimer's Disease have degeneration in the "clock" part of their brains. In this study, we wanted to examine whether there were any circadian problems much earlier in Alzheimer's Disease, when people do not have any memory or thinking problems at all. We measured circadian function in 189 people with an actigraph, which is an activity monitor worn like a watch, for 1-2 weeks. Brain scans and studies of cerebrospinal fluid were used to determine who had preclinical Alzheimer's Disease, meaning they have the brain changes of Alzheimer's but do not have symptoms yet.  (more…)
Author Interviews, Circadian Rhythm, Toxin Research / 20.01.2017

MedicalResearch.com Interview with: Rajendram Rajnarayanan PhD Department of Pharmacology and Toxicology Assistant Professor Jacobs School of Medicine and Biomedical Sciences University of Buffalo MedicalResearch.com: What is the background for this study? What are the main findings? Response: Human exposure to environmental chemicals i.e., insecticides and pesticides increases the risk of various diseases by directly interacting with proteins or signaling pathways in the endocrine or neuroendocrine system. In this study, our teamscience effort integrating big-data computation with receptor pharmacology, report for the first time that carbamate insecticides found in household and agricultural products interact with human melatonin receptors. At UB we have generated a database, we call it Chem2Risk, which contains about four million chemicals reported to have some level of toxicity. From those, after grouping the chemicals in clusters according to their similarity, we found several with potential to mimic melatonin. Wet-lab experiments confirmed that these chemicals indeed interact with melatonin receptors and have the potential to alter melatonin signaling. (more…)
Author Interviews, Endocrinology, JCEM, Metabolic Syndrome, Sleep Disorders / 03.04.2015

CDC- sleepMedicalResearch.com Interview with: Nan Hee Kim M.D., Ph.D., Professor Korea University Ansan Hospital, Gojan1-dong, Danwon-gu, Gyunggi-do, Korea MedicalResearch: What is the background for this study? Dr. Nan Hee Kim: Many individuals in modern society experience a discrepancy between social and biological time. Especially during the work or school week, we are often forced to be awake against our preferred time. In addition, the increase of light, TV, computer and internet make people stay up late at night. However, night owls (evening persons) have been reported to have more health and behavioral problems than morning persons. Evening persons experience eating disorders, negative mood and insufficient sleep compared to morning persons. They initiate sleep later in the night but need to wake up earlier than their biologic morning due to social demands. There is abundant evidence that short sleep duration and insomnia are significant risk factors for obesity and diabetes. Therefore, we feel the necessity to reveal whether evening persons are associated with metabolic abnormalities in the general population. MedicalResearch: What are the main findings? Dr. Nan Hee Kim: In middle-aged adults, people who stayed up late had a 1.7-fold increased risk for type 2 diabetes and metabolic syndrome, and a 3.2-fold increase in risk for sarcopenia as compared with morning persons, independent of sleep duration and lifestyle. Evening persons were associated with reduced muscle mass in men and increased fat mass including visceral fat in women. (more…)
Alcohol, Author Interviews, Circadian Rhythm / 20.01.2015

Timo Partonen MD, Research Professor National Institute for Health and Welfare Helsinki, FinlandMedicalResearch.com Interview with: Timo Partonen MD, Research Professor National Institute for Health and Welfare Helsinki, Finland Medical Research: What is the background for this study? What are the main findings? Response: Alcohol-use disorders are often comorbid conditions with mood and anxiety disorders. Clinical studies have demonstrated that there are abnormalities in circadian rhythms and intrinsic clocks in patients with alcohol-use disorders. Circadian clock gene variants are therefore a fruitful target of interest. The main findings are that variants of key clock genes, namely those of ARNTL, ARNTL2, PER1 and PER2, have association with alcohol consumption, with alcohol abuse, or with alcohol dependence. It is of interest that variants of a fifth clock gene of key importance, that is those of CLOCK, are associated with alcohol-use disorders only if comorbid with depressive disorders. (more…)
Author Interviews, Breast Cancer, Circadian Rhythm / 25.07.2014

MSteven M. Hill, Ph.D. Professor, Structural & Cellular Biology Edmond & Lily Safra Chair for Breast Cancer Research Co-Director, Molecular Signaling Program, Louisiana Cancer Research Consortium Director, Tulane Circadian Biology CenteredicalResearch.com Interview with Steven M. Hill, Ph.D. Professor, Structural & Cellular Biology Edmond & Lily Safra Chair for Breast Cancer Research Co-Director, Molecular Signaling Program, Louisiana Cancer Research Consortium Director, Tulane Circadian Biology Center Medical Research: What are the main findings of the study? Dr. Hill: The main findings of our study are that exposure to even dim light at night can drive human breast tumors to a hyper metabolic state, activating key tumor cell signaling pathways involved in tumor cell survival and proliferation, leading to increased tumor growth, all resulting in a tumor which is completely resistant to tamoxifen therapy. Our work shows that this effect is due to the repression of nighttime melatonin by dim light at night. When nighttime melatonin is replace the tumors become sensitive to tamoxifen resulting in cell death and tumor regression. (more…)