Publisher Health

Based on an antibody study, dried samples of easily self-collected saliva and of blood drawn from the fingertip could be useful for monitoring people’s immune responses to vaccination.
In a study by the University of Helsinki and HUS Helsinki University Hospital, the levels of antibodies associated with the SARS-CoV-2 virus were analysed in more than 1,200 employees in the social welfare and healthcare sector to determine whether there were differences in different antibody classes according to viral exposure. Dried saliva and blood samples collected between January and March 2021 were utilised in the study. The exposure and background data were collected using a questionnaire.
Based on the results, immunoglobulin G (IgG) has a 99.5% sensitivity and 75.3% specificity to distinguish people with two vaccinations from non-exposed and exposed individuals, individuals with previous Covid-19 infection, and those with one vaccination. IgG measured from saliva also had an 85.3% sensitivity and 65.7% specificity in distinguishing people with two vaccinations from the other groups.
The results of the study have been published in the Medical Microbiology and Immunology journal.
Dentists had the lowest amount of antibodies against the virus
The study attested to the exposure of social welfare and healthcare employees to coronavirus, visible in the results as elevated antibody levels. A total of 47.5% of nurses and 47.7% of doctors were seropositive due to either a previous infection, vaccination or exposure, whereas only 8.7% of dentists had been exposed to the virus. In addition to dentists, the lowest antibody levels were observed in administrative staff and social workers.

The estrogen deficiency following menopause is thought to impair women’s ability to use fat as an energy source. A study conducted at the Faculty of Sport and Health Sciences of the University of Jyväskylä shows that menopausal state or blood estrogen levels do not clearly determine the rate middle-aged women are able to use fat at rest or during exercise. Higher fat utilization did not indicate better glucose tolerance.
Estrogen is viewed as a hormone promoting fat burning. After menopause, estrogen levels drop. The resulting estrogen deficiency is thought to reduce women’s ability to use fat as an energy source, leading potentially to weight gain and metabolic health impairment. Estrogen levels can be restored with hormone replacement therapy (HRT). A study performed at the University of Jyväskylä found that the influence of menopause on fat utilization is likely minor compared with nutritional status or fitness levels.
When the rate of fat utilization was measured at rest after overnight fasting, its primary determinant was energy balance. Women whose energy intake was lower compared with their energy expenditure used fat at a higher rate. Higher fat utilization was also characterized by higher blood fatty acid and ketone levels. However, fat utilization of postmenopausal women did not differ from women who had not yet reached menopause or were using HRT.
“This was an expected result. Women burn fat also after menopause if their energy intake is less than their expenditure,” says Doctoral Researcher Jari Karppinen.
Peak fat utilization rate was measured during a bicycle test. The highest rates were achieved by women with the highest fitness and physical activity levels. Again, postmenopausal women did not differ from women who had not reached menopause or used HRT.
“If you want to improve the ability to burn fat during exercise, focus on improving your fitness with endurance training,” Karppinen continues. “In this case, you do not need to worry about menopause that much. Previous research has shown that the ability to burn fat while exercising improves with training even after menopause.”
A higher fat utilization rate does not directly indicate health or weight loss
The study also looked at whether higher fat utilization indicated better glucose tolerance. The results were somewhat surprising. In women who used fat at a higher rate while resting, blood glucose and insulin levels rose more during a subsequent glucose tolerance test. Higher peak fat utilization during exercise did not indicate better glucose tolerance.
“This finding can be explained by basic physiology,” Karppinen says. “When you use more fat at rest as an energy source, eating carbohydrates may raise your blood glucose levels more. The body is momentarily tuned to use more fat.”
The ketogenic diet is the current trend diet. Its effectiveness in weight loss is marketed with the claim that when a person follows the diet, the body begins to burn more fat from bodily sources.
“This is a common misunderstanding,” Karppinen emphasizes. “A high-fat diet indeed raises the total amount of fat used in energy production. However, this is due to increased fat intake and does not mean that you suddenly begin to shed more body fat. When energy intake is less than energy expenditure, the weight drops similarly regardless of diet macronutrient distribution.”
The study performed at the Gerontology Research Center and the Faculty of Sport and Health Sciences of the University of Jyväskylä is part of the Estrogen, microRNAs and the risk of metabolic dysfunction (EsmiRs) study. The study involved 42 women, 26 of whom had passed menopause. The remaining 16 women had higher estrogen levels: seven of the women had not yet passed menopause, and nine were on hormone replacement therapy. The fat utilization was measured by indirect calorimetry. The research project was funded by the Academy of Finland.

Using a mouse model, researchers have deciphered an alternative route that certain cells take to make organs and used that knowledge to exploit a new type of stem cells as a potential source of organs in a dish.
Imagine if you could repair damaged tissue in our organs. That is what stem cell research is working towards, because stem cells have tremendous potential to produce the cells of organs such as the liver, pancreas and intestine.
For decades, scientists have attempted to mimic the path that stem cells follow in order to form e.g. organs in embryos. However, despite extensive efforts, making cells to properly develop in the lab has been very difficult. But they may have overlooked an important step and maybe missing another type of stem cells, suggests a new study from the University of Copenhagen.
“Very simply put, a number of recent studies have attempted make a gut from stem cells in a dish. We have found a new way to do this, a way which follows different aspects of what happens in the embryo. Here, we found a new route that the embryo uses, and we describe the intermediate stage that different types of stem cells could use to make the gut and other organs,” says Ph.D. student at Martin Proks, one of the primary authors of the study from Novo Nordisk Foundation Center for Stem Cell Medicine at the University of Copenhagen (reNEW).
The researchers looked at so-called pluripotent stem cells and endoderm extra-embryonic stem cells. Extra-embryonic endoderm cells are a new stem cell line that the same research team described a couple of years back. They contribute to the gut organs by being very important support cells that provide membranes, nourishment for the membranes and more.
Group Leader and Professor Joshua Brickman at reNEW explains:
“We have identified an alternative route that so called extra-embryonic cells can use to make intestinal organs in the embryo. We then took our extra-embryonic endoderm stem cells and developed them into intestinal organ-like structures in the dish.”

The omicron wave of the COVID-19 pandemic in late 2021 and early 2022 spread like a grass fire in America’s densely populated cities but led to higher rates of death in rural counties where vaccinations are lagging.
The latest study by the University of Cincinnati, published in the journal Frontiers in Medicine, revealed striking disparities in health care between urban and rural America.
“This new national study, looking back at the delta and omicron variants of COVID-19, demonstrates the power and utility of geospatial and data visualization analysis,” said co-author Neil MacKinnon, formerly dean of UC’s James L. Winkle College of Pharmacy, now provost of Augusta University.
“It is our hope this information might be useful for decision-makers for future public health campaigns and approaches to address pandemics.”
The United States was hit by the fourth and most severe wave of the COVID-19 pandemic through a variant known as omicron that infected even many of those who were vaccinated. Researchers relied on data from 2,417 counties to track the incidence of cases and the mortality rate per 100,000 people between Dec. 1, 2021, and Jan. 31, 2022.
They found that counties with vaccination rates of less than 40% had far higher mortality rates than counties with vaccination rates of 60% or more. The study recommended that health policymakers continue to make vaccination coverage a priority.

Advances in nanotechnology have made it possible to fabricate structures out of DNA for use in biomedical applications like delivering drugs or creating vaccines, but new research in mice investigates the safety of the technology.
Using a technique called DNA Origami (DO) — a process which involves folding complementary strands of DNA into double helixes over and over again — scientists can construct a variety of tiny devices with complex shapes that could be injected in the body to deliver medicines or perform other tasks. But because this technology is still relatively new, scientists have been divided on whether nanostructures could cause dangerous immune responses or be toxic in other ways in animal systems.
Now, a team of researchers from The Ohio State University has taken an initial step toward answering that question. The study, published in the journal Small, found that while high amounts of these DNA devices can cause a slight immune response, it isn’t marked enough to be dangerous. Their findings also suggest that different shapes may be more conducive to different therapeutic applications.
“DNA is unbelievable in terms of construction and how it’s able to be manipulated and designed to form nano-robots in a very coordinated manner,” said Christopher Lucas, lead author of the study and a research scientist in mechanical and aerospace engineering at Ohio State. “We believe this technology, which has an incredible amount of potential, can be used to diagnose, treat and prevent disease.”
To test if that can be done safely, Lucas’ team used mice to compare the biodistribution and toxicity of two distinct nanostructures: a flat single-layer 2D Triangle called “Tri,” and a 3D rod-shaped structure that was given the moniker “Horse.” Over a period of 10 days, about 60 female mice were continuously given IV injections of both DO structures. But to really test the safety, the researchers repeatedly dosed the mice at a concentration 10 times greater than in previous studies.
Researchers did see that Tri and Horse created shape-dependent inflammatory responses, but because the response diminished over time, they showed that the immune reaction was relatively harmless in the long run. “It was a modest immune response, but it wasn’t toxic to the animals,” said Lucas. “Understanding that was really key as we move towards preclinical development, and ready the technology for drug delivery applications.”
When the experiment concluded, the team also collected and imaged all of the mice’s major organs, blood and urine to track the device’s final distribution throughout the body. Results showed that both types of nanostructures were internalized by a variety of immune cells, but the amount of DO still left behind differed due to their original concentrations and how long they permeated the body. Because they’re biocompatible, nanostructures also happen to clear the body relatively quickly, Lucas said. And that’s a good thing, especially if scientists want to ensure these devices could be used to target only diseased cells.
But it’s hard to predict the challenges other kinds of nanostructures might run into inside a human or animal body.
“Once you put things into a biological system there’s just so much variability to account for,” said study co-author Carlos Castro, professor of mechanical and aerospace engineering.
As for what’s next, since they’ve shown the technology isn’t toxic to mice, the team wants to start loading the devices up with chemotherapy drugs and begin learning how to use the devices to effectively target cancer cells in animals. “We’re just scratching the surface,” said Castro. “We’re revealing a whole new set of interesting questions that we can dig deeper into.”
This research was supported by the National Institutes of Health.
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Materials provided by Ohio State University. Original written by Tatyana Woodall. Note: Content may be edited for style and length.

As we age, so do our eyes; most commonly, this involves changes to our vision and new glasses, but there are more severe forms of age-related eye problems. One of these is age-related macular degeneration, which affects the macula — the back part of the eye that gives us sharp vision and the ability to distinguish details. The result is a blurriness in the central part of our visual field.
The macula is part of the eye’s retina, which is the light-sensitive tissue mostly composed of the eye’s visual cells: cone and rod photoreceptor cells. The retina also contains a layer called the retinal pigment epithelium (RPE), which has several important functions, including light absorption, cleaning up cellular waste, and keeping the other cells of the eye healthy.
The cells of the RPE also nourish and maintain the eye’s photoreceptor cells, which is why one of the most promising treatment strategies for age-related macular degeneration is to replace aging, degenerating RPE cells with new ones grown from human embryonic stem cells.
Scientist have proposed several methods for converting stem cells into RPE, but there is still a gap in our knowledge of how cells respond to these stimuli over time. For example, some protocols take a few months while others can take up to a year. And yet, scientists are not clear as to what exactly happens over that period of time.
Mixed cell populations
“None of the differentiation protocols proposed for clinical trials have been scrutinized over time at the single-cell level — we know they can make retinal pigment cells, but how cells evolve to that state remains a mystery,” says Dr Gioele La Manno, a researcher with EPFL’s Life Sciences Independent Research (ELISIR) program.

Researchers from the University of Sheffield and Stanford University in the US have discovered there are specific genetic signals in people who develop severe coronavirus infection.
It is known that age, body mass index and pre-existing health problems account for some of the disparities, but genetics also play a significant role. This pioneering research aimed to address why some people with COVID-19 become seriously ill or die, whilst others have few, if any, symptoms.
Using machine learning, researchers from the University of Sheffield and Stanford Medicine have identified more than 1,000 genes linked to the development of severe COVID-19 cases that required breathing support, or were fatal. The team was also able to identify specific types of cells in which those genes act up. It’s one of the first studies to link coronavirus-associated genes to specific biological functions.
Dr Johnathan Cooper-Knock, NIHR Clinical Lecturer in the Department of Neuroscience at the University of Sheffield and co-author of the study, said: “During the research we discovered the genetic architecture underlying coronavirus infection, and found that these 1,000 genes account for three quarters of the genetic drivers for severe COVID-19. This is significant in understanding why some people have had more severe symptoms of Covid-19 than others.”
The study, published today (14 June 2022) in the journal Cell Systems, was led by Senior Author Professor Michael P Snyder from the University of Stanford in collaboration with genetics instructor Dr Sai Zhang and neuroscientist Dr Cooper-Knock, who is currently a Stanford visiting scholar.
The research process
The research team used several large data sets to unpack the genetics behind severe COVID-19. The first data set contained genetic information from healthy human lung tissue. The data helped identify gene expression in 19 different types of lung cells, including epithelial cells that line the respiratory tract and are the first defense against infection.

Preliminary findings from a new study involving more than 6,000 adults found that taste-related genes may play a role in determining food choices and could, in turn, influence cardiometabolic health. It is one of the first studies to examine how the genetics tied to perception for all five tastes — sweet, salt, sour, bitter, and umami (savory) — are associated with consumption of food groups and cardiometabolic risk factors.
The findings suggest that the genes that determine taste perception might be important to consider when developing personalized nutrition guidance aimed at improving diet quality and reducing risk for diet-related chronic diseases like obesity, type 2 diabetes and cardiovascular diseases.
“We know that taste is one of the fundamental drivers of what we choose to eat and, by extension, our diet quality,” said Julie E. Gervis, a doctoral candidate in the Cardiovascular Nutrition Lab at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University. “Considering taste perception could help make personalized nutrition guidance more effective by identifying drivers of poor food choices and helping people learn how to minimize their influence.”
For example, if people with strong bitter taste perception tend to eat fewer cruciferous vegetables, it might be recommended that they add certain spices or choose other types of vegetables that better align with their taste perception profile. “Most people likely don’t know why they make certain food choices,” said Gervis. “This approach could provide them with guidance that would allow them to gain more control.”
Gervis will present the findings online at NUTRITION 2022 LIVE ONLINE, the flagship annual meeting of the American Society for Nutrition held June 14-16.
Although previous studies have looked at genetic factors related to single tastes in certain groups of people, this new study is unique in that it examined all five basic tastes across a broad sample of U.S. adults. It is also the first to assess whether genetic variants responsible for taste perception are associated with intake of certain food groups and with cardiometabolic risk factors.
To do this, the researchers used data from prior genome-wide association studies to identify the genetic variants associated with each of the five basic tastes. They used this information to develop a new measure known as a “polygenic taste score” that provides a single estimate of the cumulative effect of many genetic variants on perception for a given taste. A higher polygenic taste score for bitter, for example, means that a person has a higher genetic predisposition to perceive bitter tastes.
The researchers then analyzed the polygenic taste scores, diet quality and cardiometabolic risk factors for 6,230 adults in the Framingham Heart Study. The risk factors included waist circumference, blood pressure and plasma glucose, and triglyceride and HDL cholesterol concentrations.
Overall, the analysis identified certain associations between taste-related genes with food groups and cardiometabolic risk factors. The data revealed that genes related to bitter and umami tastes might play a particular role in diet quality by influencing food choices while genes related to sweet seemed to be more important to cardiometabolic health.
For example, the researchers found that study participants with a higher bitter polygenic taste score ate nearly two servings less of whole grains per week compared to participants with a lower bitter polygenic taste score. The investigators also observed that having a higher umami polygenic taste score was associated with eating fewer vegetables, particularly red and orange vegetables, and that having a higher sweet polygenic taste score tended to be associated with lower triglyceride concentrations.
The researchers caution that the findings from this specific group of adults are not necessarily generalizable to everyone. “However, our results do suggest the importance of looking at multiple tastes and food groups when investigating the determinants of eating behaviors,” said Gervis. “Going forward, it will be important to try to replicate these findings in different groups of people so that we can understand the bigger picture and better determine how to use this information to devise personalized dietary advice.”
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How healthy is your diet? It seems like a simple question, but according to a new study, it’s one that most Americans struggle to get right.
“We found that only a small percentage of U.S. adults can accurately assess the healthfulness of their diet, and interestingly, it’s mostly those who perceive their diet as poor who are able to accurately assess their diet,” said Jessica Thomson, PhD, research epidemiologist with the U.S. Department of Agriculture’s Agricultural Research Service in the Southeast Area, the study’s lead author. “Additionally, most adults overrate the quality of their diet, sometimes to a substantial degree.”
Thomson will present the findings online at NUTRITION 2022 LIVE ONLINE, the flagship annual meeting of the American Society for Nutrition held June 14-16.
The researchers wanted to find out whether a single, simple question could be used as a screening tool for nutrition studies — to replace or complement the detailed dietary questionnaires commonly used in nutrition research. Previous studies have found that self-rated health is a strong predictor of morbidity and mortality, but there is scant research on whether self-rated diet quality is predictive of the actual quality of one’s diet.
The study used data from the National Health and Nutrition Examination Survey, a nationally representative survey of U.S. adults conducted every two years. Participants were asked to complete detailed 24-hour dietary recall questionnaires and rate their diet as excellent, very good, good, fair or poor.
Researchers used the food recall questionnaires to score each participant’s diet quality. Examples of foods ranked as healthier include fruits and vegetables, whole grains, healthy fats, lower-fat dairy products, seafood and plant proteins. Foods considered less healthy included refined grains and foods high in sodium, added sugars or saturated fats.
The study revealed significant disconnects between the researcher-calculated scores and how participants ranked their own diet. Out of over 9,700 participants, about 8,000 (roughly 85%) inaccurately assessed their diet quality. Of those, almost all (99%) overrated the healthfulness of their diet.
Surprisingly, accuracy was highest among those who rated their diet as poor, among whom the researcher’s score matched the participant’s rating 97% of the time. The proportion of participants who accurately assessed their diet quality ranged from 1%-18% in the other four rating categories.
Thomson said further research could help to elucidate what factors people consider when asked to assess their diet quality. For instance, it would be helpful to know whether people are aware of particular dietary recommendations and whether they take into consideration where their food is purchased or how it is prepared.
“It’s difficult for us to say whether U.S. adults lack an accurate understanding of the components of a healthful versus unhealthful diet or whether adults perceive the healthfulness of their diet as they wish it to be — that is, higher in quality than it actually is,” said Thomson. “Until we have a better understanding of what individuals consider when assessing the healthfulness of their diet, it will be difficult to determine what knowledge and skills are necessary to improve self-assessment or perception of one’s diet quality.”
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Researchers announced early tests of a new potato processing technique designed to make our bodies digest potato starch more slowly. Laboratory demonstrations show that the approach blocks certain digestive enzymes from reaching the potato starch as quickly, leading to a more controlled release of dietary glucose.
“There is a perception that potato foods are unhealthy because eating a large amount of some potato foods can cause a rapid increase in blood sugar, which is a risk for people with diabetes or those who want to control body weight,” said Amy Lin, PhD, the study’s principal investigator and lead of the Food Carbohydrate Program of the Singapore Institute of Food and Biotechnology Innovation (SIFBI) at A*STAR. “Our team revealed that toggling the accessibility of two digestion enzymes — α-amylase and mucosal α-glucosidase — in the small intestine is a successful strategy to make dietary glucose slowly and continuously release from potatoes.”
Andrea Gomez Maqueo Cerecer, postdoctoral research fellow at A*STAR, will present the findings online at NUTRITION 2022 LIVE ONLINE, the flagship annual meeting of the American Society for Nutrition held June 14-16. The study was supervised by Lin, and other research team members included Grace Ng, Ru Min Bek and Jei Xi Wong.
For the new processing technique, researchers cut potatoes into cubes and blanched them in hot water with a food grade ingredient for 30 minutes. The ingredient used in the solution has been designated “generally recognized as safe,” a standard established by the U.S. Food and Drug Administration for substances considered safe for use in food.
This process causes a reaction with pectin, a water-soluble fiber in potatoes, creating a gelling structure that acts as a barrier between starch granules and digestive enzymes. This protective layer is porous, and the processing method allows the size of the pores to be controlled to moderate how quickly α-amylase is able to penetrate the potato parenchyma cells and degrade starch to small molecules. Converting starch molecules to glucose relies on mucosal α-glucosidase, which is too big to penetrate those pores. Therefore, the elevation of dietary glucose of processed potatoes depends on the how quickly small starch molecules leach out of parenchyma cells and are digested by mucosal α-glucosidase.
“Without our treatment, enzymes move freely in and out of cells, and starch is quickly degraded by both enzymes and rapidly converted to glucose,” said Lin. “The treatment allows the starch to be slowly degraded to prevent a spike in glycemia and then fully converted to glucose to meet our energy and nutritional needs.”
The technique is not designed to prevent the potato from being digested, but rather to slow digestion to avoid a rapid increase in blood sugar. Researchers say the modification could also help consumers feel full for a longer period after eating the treated potatoes, helping to avoid overeating.
Researchers report that the method performed well in tests with a simulated digestion process in the laboratory. Treatment increased the fraction of the starch that is considered slowly digestible from 10% to 35% and significantly reduced the ability for the enzyme a-amylase to access starch within the cell walls.
Since the process essentially pre-cooks the potatoes, treated potatoes are not shelf-stable but could be frozen and then cooked or further processed for dishes such as roasted potatoes, hash browns, soups or stir-fry, researchers say. Initial taste tests had good results in terms of digestibility and texture.
As a next step, the researchers are preparing to further test impacts on digestibility in a clinical trial. They also plan to study whether a similar approach could be used to improve other staple foods.
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