Monday, May 20, 2019
The transcatheter approach increases treatment options for high-risk patients
Researchers at the National, Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health, have developed a novel technique that prevents the obstruction of blood flow, a common fatal complication of transcatheter mitral valve replacement (TMVR). The new method, called LAMPOON, may increase treatment options for high-risk patients previously ineligible for heart valve procedures. The Journal of the American College of Cardiology published the findings online on May 20.
TMVR is used to treat mitral valve stenosis, a narrowing of the valve that restricts blood flow into the main pumping chamber of the heart. It also treats regurgitation, which occurs when the valve leaks and causes blood to flow back through the valve. Untreated, these conditions can cause pulmonary hypertension, heart enlargement, atrial fibrillation, blood clots, and heart failure.
For elderly or frail patients, TMVR offers a less invasive alternative to open heart surgery. During TMVR, doctors replace the mitral valve by delivering an artificial valve through a long, thin, flexible tube, called a catheter, through blood vessels and into the heart. But in more than 50 percent of patients, the heart’s anatomy gets in the way. The heart leaflet is pushed back and blocks blood flow. This is known as left ventricular outflow tract (LVOT) obstruction, a common and the most life-threatening complication of TMVR.
“These patients have a failing mitral valve, are not able to undergo open heart surgery, and are now rejected as candidates for TMVR because of the very high risk of left ventricular outflow tract obstruction,” said study author Jaffar M. Khan, M.D., clinician at NHLBI.
The LAMPOON procedure.
Thursday, May 16, 2019
Small-scale trial is the first randomized, controlled research of its kind
People eating ultra-processed foods ate more calories and gained more weight than when they ate a minimally processed diet, according to results from a National Institutes of Health study. The difference occurred even though meals provided to the volunteers in both the ultra-processed and minimally processed diets had the same number of calories and macronutrients. The results were published in Cell Metabolism.
This small-scale study of 20 adult volunteers, conducted by researchers at the NIH’s National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), is the first randomized controlled trial examining the effects of ultra-processed foods as defined by the NOVA classification system. This system considers foods “ultra-processed” if they have ingredients predominantly found in industrial food manufacturing, such as hydrogenated oils, high-fructose corn syrup, flavoring agents, and emulsifiers.
Previous observational studies looking at large groups of people had shown associations between diets high in processed foods and health problems. But, because none of the past studies randomly assigned people to eat specific foods and then measured the results, scientists could not say for sure whether the processed foods were a problem on their own, or whether people eating them had health problems for other reasons, such as a lack of access to fresh foods.
“Though we examined a small group, results from this tightly controlled experiment showed a clear and consistent difference between the two diets,” said Kevin D. Hall, Ph.D., an NIDDK senior investigator and the study’s lead author. “This is the first study to demonstrate causality — that ultra-processed foods cause people to eat too many calories and gain weight.”
Researchers from the National Institutes of Health Kevin D. Hall, Ph.D., center, and Stephanie Chung, M.B.B.S., right, talk with a study participant at the NIH Clinical Center.
Friday, May 3, 2019
Testing the blood for free fatty acids could help doctors verify if children fasted before undergoing tests
Testing the blood for free fatty acids could help doctors verify if children fasted before undergoing tests for diabetes or other medical conditions, according to researchers at the National Institutes of Health. Their study appears in Pediatrics.
An overnight fast is required for the blood glucose test used to diagnose type 2 diabetes. However, earlier studies suggest that at least 6% of patients don’t fast sufficiently, potentially raising blood glucose and leading to an incorrect diagnosis and additional testing. Researchers from NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and other institutions paired the blood glucose test with a blood test for free fatty acids. Unlike blood glucose, which declines after a fast and increases after a meal, the blood level of free fatty acids increases after a fast and drops after a meal.
The researchers analyzed blood test results of children who participated in studies of obesity at the NIH Clinical Center. They compared free fatty acid test results of children who were admitted as inpatients — and whose food intakes were controlled by hospital staff — to those of children who participated as outpatients. They found that 9.7% of outpatients had lower free fatty acid levels, indicating they probably did not fast, compared to only 1.6% of inpatients. The authors suggest that testing for free fatty acids may help doctors interpret glucose test results in children, decreasing the number of children who need to be re-tested for high blood sugar.
Tuesday, April 30, 2019
NIH study suggests supplement that reduces risk of birth defects may also have maternal health benefit
Taking a folic acid supplement daily before pregnancy may reduce the risk of gestational, or pregnancy-related, diabetes, according to a study by researchers at the National Institutes of Health and other institutions. The findings appear in Diabetes Care.
Folic acid is the synthetic form of folate, or vitamin B9, which is found in leafy green vegetables, nuts, peas, beans and other foods. The U.S. Preventive Services Task Force recommends that all women of reproductive age take a daily supplement containing 400 to 800 micrograms of folic acid to reduce the risk of conceiving a child with a neural tube defect, a class of birth defects affecting the brain and spinal cord.
Gestational diabetes results when the level of blood sugar, or glucose, rises too high. It increases a woman’s chances for cesarean delivery and for blood pressure disorders during pregnancy. It also raises the risk of cardiovascular disease and type 2 diabetes later in life. For infants, gestational diabetes increases the risk of large birth size and of obesity during childhood and adulthood.
Monday, April 29, 2019
NIH-supported study highlights the importance of responsible portrayal of suicide by the media.
The Netflix show “13 Reasons Why” was associated with a 28.9% increase in suicide rates among U.S. youth ages 10-17 in the month (April 2017) following the shows release, after accounting for ongoing trends in suicide rates, according to a study published today in Journal of the American Academy of Child and Adolescent Psychiatry. The findings highlight the necessity of using best practices when portraying suicide in popular entertainment and in the media. The study was conducted by researchers at several universities, hospitals, and the National Institute of Mental Health (NIMH), part of the National Institutes of Health. NIMH also funded the study.
The number of deaths by suicide recorded in April 2017 was greater than the number seen in any single month during the five-year period examined by the researchers. When researchers analyzed the data by sex, they found the increase in the suicide rate was primarily driven by significant increases in suicide in young males. While suicide rates for females increased after the show’s release, the increase was not statistically significant.
“The results of this study should raise awareness that young people are particularly vulnerable to the media,” said study author Lisa Horowitz, Ph.D., M.P.H., a clinical scientist in the NIMH Intramural Research Program. “All disciplines, including the media, need to take good care to be constructive and thoughtful about topics that intersect with public health crises.”
Suicidal thoughts or actions (even in very young children) are a sign of extreme distress and should not be ignored.
If you or someone you know needs immediate help, contact the National Suicide Prevention Lifeline
at 1-800-273-TALK (8255) or Crisis Text Line: text “home” to 741741.Learn more
about ways you can help someone who might be at risk for self-harm.
Thursday, April 18, 2019
NIH scientists identify paradoxical response to HIV medication in five individuals
Antiretroviral therapy (ART) is usually very effective at suppressing HIV in the body, allowing a person’s immune system to recover by preventing the virus from destroying CD4+ T cells(link is external). Scientists have now identified a rare, paradoxical response to ART known as extreme immune decline, or EXID. Five individuals evaluated at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, experienced a significant decline in CD4+ T cell levels despite suppression of HIV below detectable levels for more than three years, according to a report published online today in JCI Insight. The research team was led by Irini Sereti, M.D., chief of the HIV Pathogenesis Section in NIAID’s Laboratory of Immunoregulation, and Andrea Lisco, M.D., Ph.D.
The NIAID researchers found that the immune systems of people with EXID fared even worse than those of another subset of individuals defined as immunological-non-responders, or INRs, who respond inadequately to ART. INR participants consistently taking ART for four years had CD4+ T cell counts that increased on average by 193 cells per microliter (µL) of blood. Participants who responded normally to ART increased their CD4+ T cell count by more than twice that amount. In contrast, the five participants with EXID experienced an average decline of 157 CD4+ T cells/µL while consistently maintaining viral suppression on ART.
Colorized scanning electron micrograph of a T lymphocyte.
Wednesday, April 17, 2019
NIH scientists and funding contributed to development of experimental treatment
A small clinical trial has shown that gene therapy can safely correct the immune systems of infants newly diagnosed with a rare, life-threatening inherited disorder in which infection-fighting immune cells do not develop or function normally. Eight infants with the disorder, called X-linked severe combined immunodeficiency (X-SCID), received an experimental gene therapy co-developed by National Institutes of Health scientists. They experienced substantial improvements in immune system function and were growing normally up to two years after treatment. The new approach appears safer and more effective than previously tested gene-therapy strategies for X-SCID.
These interim results from the clinical trial, supported in part by NIH, were published today in The New England Journal of Medicine.
Infants with X-SCID, caused by mutations in the IL2RG gene, are highly susceptible to severe infections. If untreated, the disease is fatal, usually within the first year or two of life. Infants with X-SCID typically are treated with transplants of blood-forming stem cells, ideally from a genetically matched sibling. However, less than 20% of infants with the disease have such a donor. Those without a matched sibling typically receive transplants from a parent or other donor, which are lifesaving, but often only partially restore immunity. These patients require lifelong treatment and may continue to experience complex medical problems, including chronic infections.
Tuesday, April 16, 2019
NIH research could be a step toward a treatment to prevent heart attacks
Two proteins that bind to stress hormones work together to maintain a healthy heart in mice, according to scientists at the National Institutes of Health and their collaborators. These proteins, stress hormone receptors known as the glucocorticoid receptor (GR) and mineralocorticoid receptor (MR), act in concert to help support heart health. When the signaling between the two receptors is out of balance, the mice have heart disease.
The work, published April 16 in Science Signaling, may lead to the development of therapeutic compounds that help people with an increased risk of a heart attack.
Stress increases risk of dying from heart failure by inducing adrenal glands to make a hormone called cortisol. Cortisol is involved in the fight-or-flight response and binds to GRs and MRs in different tissues of the body to reduce inflammation, among other functions. If the level of cortisol remains too high over a long period of time, common risk factors for heart disease may arise, such as increased cholesterol and glucose in the blood and high blood pressure.
Lead author Robert Oakley, Ph.D., first identified a malfunctioning GR in the 1990s when he was a graduate student working with John Cidlowski, Ph.D., at the University of North Carolina at Chapel Hill. Soon after the discovery, other scientists determined that people with above average amounts of this altered GR had greater risk of heart disease. Based on this finding, Oakley and Cidlowski tested a mouse strain without heart GR in their lab at the National Institute of Environmental Health Sciences (NIEHS), part of NIH. These animals spontaneously developed enlarged hearts leading to heart failure and death. When the team produced a mouse strain missing cardiac MR, the animals’ hearts functioned normally.
Friday, April 12, 2019
NIH study suggests our brains may use short rest periods to strengthen memories
In a study of healthy volunteers, National Institutes of Health researchers found that our brains may solidify the memories of new skills we just practiced a few seconds earlier by taking a short rest. The results highlight the critically important role rest may play in learning.
“Everyone thinks you need to ‘practice, practice, practice’ when learning something new. Instead, we found that resting, early and often, may be just as critical to learning as practice,” said Leonardo G. Cohen, M.D., Ph.D., senior investigator at NIH’s National Institute of Neurological Disorders and Stroke and a senior author of the paper published in the journal Current Biology. “Our ultimate hope is that the results of our experiments will help patients recover from the paralyzing effects caused by strokes and other neurological injuries by informing the strategies they use to ‘relearn’ lost skills.”
The study was led by Marlene Bönstrup, M.D., a postdoctoral fellow in Dr. Cohen’s lab. Like many scientists, she held the general belief that our brains needed long periods of rest, such as a good night’s sleep, to strengthen the memories formed while practicing a newly learned skill. But after looking at brain waves recorded from healthy volunteers in learning and memory experiments at the NIH Clinical Center, she started to question the idea.
In a study of healthy volunteers, NIH researchers found that taking short breaks, early and often, may help our brains learn new skills.
Wednesday, April 10, 2019
Small-scale, NIH-led clinical study offers early hope for developing a treatment
The anti-cancer drug pembrolizumab has shown promise in slowing or stopping the progression of progressive multifocal leukoencephalopathy (PML), a typically fatal infection of the brain caused by the JC virus (JCV). This finding comes from a small-scale study by scientists at National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health. The study appears in the New England Journal of Medicine.
Pembrolizumab blocks the interaction between two proteins, PD-1 and PD-L1. Normally, these proteins work by putting the brakes on the immune system to limit excessive inflammation. However, some tumors that have PD-L1 on their surface can exploit this “off switch,” limiting the immune system’s ability to attack the cancer. Recent studies of PML patients have suggested that this mechanism may also be involved in JCV brain infections.
“We found both PD-1 and PD-L1 proteins in the infected parts of brains of patients with PML,” said Irene Cortese, M.D., director of the NINDS Neuroimmunology Clinic and first author of the paper. “This led us to ask whether pembrolizumab could be a potential treatment for PML.”
MRI of a PML patient showing significant lesions in the brain (white signal).