Research advances from the National Institutes of Health (NIH) Intramural Research Program (IRP) often make headlines. Read the news releases that describe our most recent findings:
Whether you’re shedding pounds with the help of effective new medicines, slimming down after weight loss surgery or cutting calories and adding exercise, there will come a day when the numbers on the scale stop going down, and you hit the dreaded weight loss plateau.
In a recent study, Kevin Hall, a researcher at the National Institutes of Health who specializes in measuring metabolism and weight change, looked at when weight loss typically stops depending on the method people were using todrop pounds. He broke down the plateau into mathematical models using data from high-quality clinical trials of different ways to lose weight to understand why people stop losing when they do. The study published Monday in the journal Obesity.
The global COVID-19 pandemic has taken a toll on Black, American Indian/Alaska Native, and Latino individuals in the United States, causing more deaths by population size, both directly and indirectly, in these groups compared with white or Asian individuals. The findings, from a large surveillance study led by researchers at the National Cancer Institute (NCI), part of the National Institutes of Health (NIH), appeared October 5, 2021, in Annals of Internal Medicine.
“Focusing on COVID-19 deaths alone without examining total excess deaths—that is, deaths due to non-COVID-19 causes as well as to COVID-19—may underestimate the true impact of the pandemic,” said Meredith S. Shiels, Ph.D., M.H.S., senior investigator in the Infections and Immunoepidemiology Branch in NCI’s Division of Cancer Epidemiology and Genetics, who led the study. “These data highlight the profound impact of long-standing inequities.”
Scientists at NCI have a long history of tracking mortality trends in the United States, mainly focusing on cancer death rates. More recently, these investigators have been applying their expertise in analyzing national surveillance data to better understand the impact of the COVID-19 pandemic on excess deaths by racial and ethnic group.
NIH study in mice demonstrates the importance of quickly addressing infection
Traumatic brain injury (TBI) and other injuries to blood vessels in the brain, like stroke, are a leading cause of long-term disability or death. Researchers at the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health, have found a possible explanation for why some patients recover much more poorly from brain injury if they later become infected. The findings were published in Nature Immunology.
Making use of a mouse model for mild TBI (mTBI) that they had developed previously, the team of researchers led by NINDS scientist Dorian McGavern, Ph.D., discovered that viral, fungal, or a mimic for bacterial infections all impacted blood vessel repair within the meninges, the protective covering of the brain. When they looked closer, they observed that some cells of the immune system no longer moved into the site of the injury, which occurred in the uninfected animals, suggesting they were responding to systemic infection. The study also looked in a second injury model affecting the blood vessels in the brain, called a cerebrovascular injury (CVI), and saw a similar effect on repair.
“Evolution prioritizes mobilizing the immune system to fight off infection over repair,” said Dr. McGavern. “Because the body is dealing with a greater threat, cells that would normally repair the damaged blood vessels in or around the brain are needed elsewhere.”
Seven days after mTBI, the blood vessels (stained in red) in the tissues around the brain are not completely repaired. A marker for intact vessels was used (labeled in green) to distinguish fully functional blood vessels (yellow) from ones that are still damaged (red).
Patterns of methamphetamine use have become riskier, diversified across U.S. population
Overdose deaths involving methamphetamine nearly tripled from 2015 to 2019 among people ages 18-64 in the United States, according to a study by the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health. The number of people who reported using methamphetamine during this time did not increase as steeply, but the analysis found that populations with methamphetamine use disorder have become more diverse. Published today in JAMA Psychiatry, the study suggests that increases in higher-risk patterns of methamphetamine use, such as increases in methamphetamine use disorder, frequent use, and use of other drugs at the same time, may be contributing to the rise in overdose deaths.
“We are in the midst of an overdose crisis in the United States, and this tragic trajectory goes far beyond an opioid epidemic. In addition to heroin, methamphetamine and cocaine are becoming more dangerous due to contamination with highly potent fentanyl, and increases in higher risk use patterns such as multiple substance use and regular use,” said NIDA Director Nora D. Volkow, M.D., one of the authors of the study. “Public health approaches must be tailored to address methamphetamine use across the diverse communities at risk, and particularly for American Indian and Alaska Native communities, who have the highest risk for methamphetamine misuse and are too often underserved.”
In 2020, more than 93,000 Americans died from drug overdoses, marking the largest one-year increase in overdose deaths ever recorded, according to provisional data from the U.S. Centers for Disease Control and Prevention. This increase has largely been driven by rising overdoses involving synthetic opioids, primarily fentanyl. Overdose deaths involving psychostimulants, and particularly methamphetamine, have also risen steeply in recent years, and many of these deaths involved use of an opioid at the same time. However, questions remain on how trends in methamphetamine use contribute to greater risk for overdose deaths.
Understanding Structure of HCV Proteins Could Aid in Vaccine Development
In a new paper published in Nature, scientists from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, describe the structure of a key protein on the surface of the hepatitis C virus (HCV) and how it interacts with its receptor found on some human cells. The findings provide new leads for developing an HCV vaccine.
Hepatitis C is one of the most common bloodborne infections in the United States. Although it may not cause any symptoms in its early stages, untreated chronic infections can lead to severe liver damage, cancer, and death. Concerningly, infections are on the rise among young adults, largely due to exposure resulting from shared drug-injectables. No vaccine is available to prevent HCV infection.
HCV is usually transmitted via blood, such as during birth or when drug-injection equipment is shared. Because HCV may not cause any symptoms for years after initial infection, infections often go undetected. According to the U.S. Centers for Disease Control and Prevention, an estimated 2.4 million people are living with hepatitis C infection in the United States. More than half of all people infected with HCV are thought to develop chronic infection. HCV is a leading cause of cirrhosis, liver failure requiring transplant, and the leading cause of death from liver disease. Although effective antiviral drugs are available to treat HCV infection, they are expensive and do not prevent reinfection.
A transmission electron microscope image of hepatitis virus particles. Image credit: CDC/E.H. Cook, Jr.
Study lays the groundwork for potential new therapies for progressive multiple sclerosis
Chronic lesions with inflamed rims, or “smoldering” plaques, in the brains of people with multiple sclerosis (MS) have been linked to more aggressive and disabling forms of the disease. Using brain tissue from humans, researchers at the National Institutes of Health’s National Institute of Neurological Disorders and Stroke (NINDS) built a detailed cellular map of chronic MS lesions, identifying genes that play a critical role in lesion repair and revealing potential new therapeutic targets for progressive MS. The study was published in Nature.
“We identified a set of cells that appear to be driving some of the chronic inflammation seen in progressive MS,” said Daniel Reich, M.D., Ph.D., senior investigator at NINDS. “These results give us a way to test new therapies that might speed up the brain’s healing process and prevent brain damage that occurs over time.”
Chronic active lesions are characterized by a slow, expanding rim of immune cells called microglia. Microglia normally help protect the brain, but in MS and other neurodegenerative diseases, they can become overactive and secrete toxic molecules that damage nerve cells. Other cells found at the edge of the lesions, such as astrocytes and lymphocytes, may also contribute to ongoing tissue damage. Prior studies suggest that microglia are the main culprits behind lesion expansion, but the exact types of cells found near lesions and their biological mechanisms are elusive.
Mapping multiple sclerosis lesions. Researchers used single-cell RNA sequencing to map the cells found at the edges of chronic MS lesions.
A genomic analysis of lung cancer in people with no history of smoking has found that a majority of these tumors arise from the accumulation of mutations caused by natural processes in the body. This study was conducted by an international team led by researchers at the National Cancer Institute (NCI), part of the National Institutes of Health (NIH), and describes for the first time three molecular subtypes of lung cancer in people who have never smoked.
These insights will help unlock the mystery of how lung cancer arises in people who have no history of smoking and may guide the development of more precise clinical treatments. The findings were published September 6, 2021, in Nature Genetics.
“What we’re seeing is that there are different subtypes of lung cancer in never smokers that have distinct molecular characteristics and evolutionary processes,” said epidemiologist Maria Teresa Landi, M.D., Ph.D., of the Integrative Tumor Epidemiology Branch in NCI’s Division of Cancer Epidemiology and Genetics, who led the study, which was done in collaboration with researchers at the National Institute of Environmental Health Sciences, another part of NIH, and other institutions. “In the future we may be able to have different treatments based on these subtypes.”
Illustration of lungs made up of DNA sequences. A magnifying glass hovers over a portion of a DNA sequence showing a mutational change.
Neurofibromatosis type 1, or NF1, is the most common cancer predisposition syndrome, affecting 1 in 3,000 people worldwide
People with an inherited condition known as neurofibromatosis type 1, or NF1, often develop non-cancerous, or benign, tumors that grow along nerves. These tumors can sometimes turn into aggressive cancers, but there hasn’t been a good way to determine whether this transformation to cancer has happened.
Researchers from the National Cancer Institute’s (NCI) Center for Cancer Research, part of the National Institutes of Health, and Washington University School of Medicine in St. Louis have developed a blood test that, they believe, could one day offer a highly sensitive and inexpensive approach to detect cancer early in people with NF1. The blood test could also help doctors monitor how well patients are responding to treatment for their cancer.
The findings are published in the August 31 issue of PLOS Medicine.
National Institutes of Health scientists studying SARS-CoV-2, the virus that causes COVID-19, have defined in Syrian hamsters how different routes of virus exposure are linked to disease severity. Their study, published in Nature Communications, details the efficiency of airborne transmission between hamsters and examines how the virus replicates and causes disease throughout the respiratory system. Their work also shows that virus transmission via fomites—exposure from contaminated surface contact — is markedly less efficient than airborne transmission but does occur.
To investigate how different routes of exposure affected disease development, the scientists exposed hamsters to SARS-CoV-2 via both aerosols and fomites. For aerosol exposure, the scientists used equipment that controlled the size of virus-loaded droplets. For fomite exposure, they placed a dish contaminated with SARS-CoV-2 in the animal cages.
The scientists found that aerosol exposure directly deposited SARS-CoV-2 deep into the lungs, whereas fomite exposure resulted in initial virus replication in the nose. Regardless of exposure route, animals had SARS-CoV-2 replicating in the lungs, but lung damage was more severe in aerosol-exposed animals compared to the fomite group.
Scientists at the National Institutes of Health (NIH) have developed a new sample preparation method to detect SARS-Cov-2, the virus that causes COVID-19. The method bypasses extraction of the virus’ genetic RNA material, simplifying sample purification and potentially reducing test time and cost. The method is the result of a collaboration among researchers at the National Eye Institute (NEI), the NIH Clinical Center (CC), and the National Institute of Dental and Craniofacial Research (NIDCR).
Diagnostic testing remains a crucial tool in the fight against the COVID-19 pandemic. Standard tests for detection of SARS-CoV-2 involve amplifying viral RNA to detectable levels using a technique called quantitative reverse transcription PCR (RT-qPCR). But first, the RNA must be extracted from the sample. Manufacturers of RNA extraction kits have had difficulty keeping up with demand during the COVID-19 pandemic, hindering testing capacity worldwide. With new virus variants emerging, the need for better, faster tests is greater than ever.
A team led by Robert B. Hufnagel, M.D., Ph.D., chief of the NEI Medical Genetics and Ophthalmic Genomic Unit, and Bin Guan, Ph.D., a fellow at the Ophthalmic Genomics Laboratory at NEI, used a chelating agent made by the lab supply company Bio-Rad called Chelex 100 resin to preserve SARS-CoV-2 RNA in samples for detection by RT-qPCR.
“We used nasopharyngeal and saliva samples with various virion concentrations to evaluate whether they could be used for direct RNA detection,” said Guan, the lead author of a report on the technique, which published this week in iScience. “The answer was yes, with markedly high sensitivity. Also, this preparation inactivated the virus, making it safer for lab personnel to handle positive samples.”
One dose of a new monoclonal antibody discovered and developed at the National Institutes of Health safely prevented malaria for up to nine months in people who were exposed to the malaria parasite. The small, carefully monitored clinical trial is the first to demonstrate that a monoclonal antibody can prevent malaria in people. The trial was sponsored and conducted by scientists from the Vaccine Research Center (VRC) of the National Institute of Allergy and Infectious Diseases (NIAID), part of NIH, and was funded by NIAID. The findings were published today in The New England Journal of Medicine.
“Malaria continues to be a major cause of illness and death in many regions of the world, especially in infants and young children; therefore, new tools are needed to prevent this deadly disease,” said NIAID Director Anthony S. Fauci, M.D. “The results reported today suggest that a single infusion of a monoclonal antibody can protect people from malaria for at least 9 months. Additional research is needed, however, to confirm and extend this finding.”
According to the World Health Organization, an estimated 229 million cases of malaria occurred worldwide in 2019, resulting in an estimated 409,000 deaths, mostly in children in sub-Saharan Africa. So far, no licensed or experimental malaria vaccine that has completed Phase 3 testing provides more than 50% protection from the disease over the course of a year or longer.
Colorized electron micrograph showing malaria parasite (right, blue) attaching to a human red blood cell. The inset shows a detail of the attachment point at higher magnification.
