Tag: children

Possible Biological Explanations for Kids’ Escape from COVID-19

On By A.P.In UncategorizedLeave a comment


Infected children may harbor SARS-CoV-2 while showing less-severe symptoms than adults. Their young immune systems, ACE2 receptor levels, and even exposure to other coronaviruses might play a role in their resilience.

by Anthony King

Since SARS-CoV-2, the virus responsible for the COVID-19 pandemic, was first recognized as a close cousin of the virus that caused the SARS outbreak of 2003, scientists have looked to the experience of that earlier epidemic to glean insight into the current global health crisis.

Kids were largely unaffected in the original SARS outbreak. In Hong Kong, no one under the age of 24 years died, while more than 50 percent of patients over 65 succumbed to the infection. Globally, less than 10 percent of those diagnosed with SARS were children, and only 5 percent of them required intensive care.

“There were repeated incursions from animals to humans, with both SARS and MERS, and the assumption by many was maybe children are just not exposed to the infected civet cats or camels,” says virologist Kanta Subbarao of the Doherty Institute in Melbourne, Australia.

A very similar pattern has been observed with the new outbreak of COVID-19. Within Wuhan, no children tested positive between November 2019 and the second week of January, and the elderly proved particularly vulnerable. The Chinese Centers for Disease Control and Prevention reported in mid-February that out of 44,672 confirmed cases of COVID-19, 86.6 percent were between 30 and 79 years of age. The oldest among them were at greatest risk of death. And in a study of 1,099 patients in China, just 0.9 percent of confirmed cases were under the age of nine, while only 1.2 percent were between 10 and 19 years old.

Now, evidence is emerging that while few children suffer severely from COVID-19, they do get infected. A recent study even found evidence of viral excretion in children from rectal swabs. “At the moment it doesn’t seem to be causing much in the way of serious disease in young people, particularly children,” says virologist Robin Shattock of Imperial College London. However, he adds, “it is quite likely that children are an important source of the virus.”

“There is good evidence that children get infected and have a fairly high titre of virus but just don’t have serious disease,” agrees Ralph Baric, a coronavirus researcher at the University of North Carolina at Chapel Hill. He saw a similar phenomenon in his mouse studies with the original SARS coronavirus (SARS-CoV). Although SARS-CoV can replicate fairly well, “younger animals are really resistant to infection in terms of the disease,” he says. When Baric tested older animals, he says, the severity of SARS illnesses rose. In one experiment, one-fifth of mice infected with SARS aged 3–4 weeks died, whereas all of the mice 7–8 weeks old died.

Subbarao has also found that young adult mice, at six weeks old, can clear SARS-CoV with no significant clinical symptoms. “When we used the same virus in 12-month-old mice, which is by no means really old, there were more clinical signs,” she says. These results indicate that both the original SARS-CoV and the one circulating now may infect children, but not make them ill. “The animal data supports the idea that they are infected but do not develop disease, because our young mice have the same levels of virus as old mice but do not get sick,” says Stanley Perlman, an immunologist at the University of Iowa. “It is not a question of infection.”

The work on mice is now being supported by emerging epidemiological data. A preprint posted to medRxiv on March 4 analyzed 391 COVID-19 cases and 1,286 of their close contacts. The authors concluded that children are at a similar risk of infection as the general population, though less likely to have severe symptoms.

An aging immune system

One explanation for the correlation between age and disease severity is that as humans’ immune systems age, more cells become inactive. “As you age, your immune system undergoes senescence and loses its capacity to respond as effectively or be regulated as effectively,” says Baric.

Another explanation, which Perlman favors, is tied to the aging lung environment. In order for individuals not to easily develop asthma or overreact to environmental irritants such as pollen or pollution, aged lungs counter the usual immune reaction with some tamping down of inflammation. As a result, says Perlman, the lungs do not respond quickly enough to a viral infection. For instance, when his group makes the lungs of older mice more like those of young mice by altering prostaglandins, compounds that respond to tissue injury, “then the mice do well and they can clear the [SARS] infection and don’t get sick,” says Perlman.

In experiments reported in 2010, Perlman and his colleagues showed that T cells are especially important in clearing viruses from mice infected with SARS-CoV. “It is almost certain we need both an antibody- and T cell–response to do well” against COVID-19 infection, says Perlman. His suspicion is that the young immune system and its efficient T cells do a superior job of responding to SARS-CoV-2. A 2010 study led by Subbarao also stressed the importance of CD4+ helper T cells, which stimulate B cells to make antibodies against pathogens, in controlling SARS-CoV infection in mice.

“It could be that the type of T cell that dominates early in life is better at repelling this virus,” says immunologist Kingston Mills of Trinity College Dublin. He also proposes that young children’s higher production of a type of T cell called Th2 might guard against runaway inflammatory responses to SARS-CoV-2. Perlman doesn’t support the proposed role of a bias toward Th2 cells in the case of this viral infection, but he does agree that an immune overreaction is problematic.

“The innate response is delayed in the elderly, so ends up playing catch-up and is exuberant,” Perlman writes in an email to The Scientist.

ACE2 receptor

SARS-CoV and SARS-CoV-2 both use the same keyhole to enter cells, the ACE2 receptor. There’s an abundance of this receptor in cells in the lower lung, which may explain the high incidence of pneumonia and bronchitis in those with severe COVID-19 infection. A recent study showed that ACE2 is also highly expressed in the mouth and tongue, granting the virus easy access to a new host. ACE2 receptor abundance goes down in the elderly in all these tissues, but, counterintuitively, this might place them at a greater risk of severe illness.

This is because the ACE2 enzyme is an important regulator of the immune response, especially inflammation. It protects mice against acute lung injury triggered by sepsis. And a 2014 study found that the ACE2 enzyme offers protection against lethal avian influenza. Some patients with better outcomes had higher levels of the protein in their sera, and turning off the gene for ACE2 led to severe lung damage in mice infected with H5N1, while treating mice with human ACE2 dampened lung injury.

A fall in ACE2 activity in the elderly is partly to blame for humans’ poorer ability to put the brakes on our inflammatory response as we age, according to emailed comments from Hongpeng Jia of Johns Hopkins Medicine. Reduced abundance of ACE2 receptors in older adults could leave them less able to cope with SARS-CoV-2, says Baric, though the hypothesis still needs more research.

Exposure to other coronaviruses

There are four other coronaviruses that infect humans, with symptoms typical of a common cold. These viruses are common in children. “We don’t know which of them, if any, might provide some cross immunity,” says Subbarao. It could be that immunity to viral proteins, obtained from circulating “common cold” viruses, moderates the course of COVID-19.

This is a “hand-waving hypothesis,” Subbarao adds, but one that is worth testing. Recently, it has been suggested that plasma from people who’ve recovered from COVID-19 could be transfused into patients infected with SARS-CoV-2 to treat them.

“I don’t think anyone in the field knows why the disease is less robust in extremely young animals or humans,” Baric tells The Scientist. It is also still too early to know how much learned from the first SARS coronavirus applies to SARS-CoV-2. “SARS-CoV-1 will tell us a lot, but I think there is new information we are going to learn about SARS-CoV-2,” Perlman acknowledges.

https://www.the-scientist.com/news-opinion/possible-biological-explanations-for-kids-escape-from-covid-19-67273?utm_campaign=TS_DAILY%20NEWSLETTER_2020&utm_source=hs_email&utm_medium=email&utm_content=84840060&_hsenc=p2ANqtz-_QBhFeETnCdgO-hMkDQF0G0KlDcX_Lu5wb8FR6n0M2nggE4q841plJ_OtOZv-bbBKiOgV9emt0eX9q7t-0l6Og3pcCVQ&_hsmi=84840060

Young children’s oral bacteria may predict obesity

On By A.P.In UncategorizedLeave a comment

microbial-activity-in-the-mouth-may-help-identify-autism-in-children

Weight gain trajectories in early childhood are related to the composition of oral bacteria of two-year-old children, suggesting that this understudied aspect of a child’s microbiota — the collection of microorganisms, including beneficial bacteria, residing in the mouth — could serve as an early indicator for childhood obesity. A study describing the results appears September 19 in the journal Scientific Reports.

“One in three children in the United States is overweight or obese,” said Kateryna Makova, Pentz Professor of Biology and senior author of the paper. “If we can find early indicators of obesity in young children, we can help parents and physicians take preventive measures.”

The study is part of a larger project with researchers and clinicians at the Penn State Milton S. Hershey Medical Center called INSIGHT, led by Ian Paul, professor of pediatrics at the Medical Center, and Leann Birch, professor of foods and nutrition at the University of Georgia. The INSIGHT trial includes nearly 300 children and tests whether a responsive parenting intervention during a child’s early life can prevent the development of obesity. It is also designed to identify biological and social risk factors for obesity.

“In this study, we show that a child’s oral microbiota at two years of age is related to their weight gain over their first two years after birth,” said Makova.

The human digestive tract is filled with a diverse array of microorganisms, including beneficial bacteria, that help ensure proper digestion and support the immune system. This “microbiota” shifts as a person’s diet changes and can vary greatly among individuals. Variation in gut microbiota has been linked to obesity in some adults and adolescents, but the potential relationship between oral microbiota and weight gain in children had not been explored prior to this study.

“The oral microbiota is usually studied in relation to periodontal disease, and periodontal disease has in some cases been linked to obesity,” said Sarah Craig, a postdoctoral scholar in biology at Penn State and first author of the paper. “Here, we explored any potential direct associations between the oral microbiota and child weight gain. Rather than simply noting whether a child was overweight at the age of two, we used growth curves from their first two years after birth, which provides a more complete picture of how the child is growing. This approach is highly innovative for a study of this kind, and gives greater statistical power to detect relationships.”

Among 226 children from central Pennsylvania, the oral microbiota of those with rapid infant weight gain — a strong risk factor for childhood obesity — was less diverse, meaning it contained fewer groups of bacteria. These children also had a higher ratio of Firmicutes to Bacteroidetes, two of the most common bacteria groups found in the human microbiota.

“A healthy person usually has a lot of different bacteria within their gut microbiota,” said Craig. “This high diversity helps protect against inflammation or harmful bacteria and is important for the stability of digestion in the face of changes to diet or environment. There’s also a certain balance of these two common bacteria groups, Firmicutes and Bacteroidetes, that tends to work best under normal healthy conditions, and disruptions to that balance could lead to dysregulation in digestion.”

Lower diversity and higher Firmicutes to Bacteroidetes (F:B) ratio in gut microbiota are sometimes observed as a characteristic of adults and adolescents with obesity. However, the researchers did not see a relationship of weight gain with either of these measures in gut microbiota of two-year-olds, suggesting that the gut microbiota may not be completely established at two years of age and may still be undergoing many changes.

“There are usually dramatic changes to an individual’s microbiota as they develop during early childhood,” said Makova. “Our results suggest that signatures of obesity may be established earlier in oral microbiota than in gut microbiota. If we can confirm this in other groups of children outside of Pennsylvania, we may be able to develop a test of oral microbiota that could be used in clinical care to identify children who are at risk for developing obesity. This is particularly exciting because oral samples are easier to obtain than those from the gut, which require fecal samples.”

Interestingly, weight gain in children was also related to diversity of their mother’s oral microbiota. This could reflect a genetic predisposition of the mother and child to having a similar microbiota, or the mother and child having a similar diet and environment.

“It could be a simple explanation like a shared diet or genetics, but it might also be related to obesity,” said Makova. “We don’t know for sure yet, but if there is an oral microbiome signature linked to the dynamics of weight gain in early childhood, there is a particular urgency to understand it. Now we are using additional techniques to look at specific species of bacteria–rather than larger taxonomic groups of bacteria–in both the mothers and children to see whether specific bacteria species influence weight gain and the risk of obesity.”

In addition to Makova, Craig, Paul, and Birch, the research team includes Jennifer Savage, Michele Marini, Jennifer Stokes, Anton Nekrutenko, Matthew Reimherr, and Francesca Chiaromonte from Penn State, Daniel Blankenberg from the Cleveland Clinic, and Alice Carla Luisa Parodi from Politecnico di Milano. INSIGHT (Intervention Nurses Start Infants Growing on Healthy Trajectories) is coordinated through the Penn State Milton S. Hershey Medical Center.

This work is supported by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK); the Penn State Eberly College of Science; the Penn State Institute for Cyberscience; the National Center for Research Resources and the National Center for Advancing Translational Sciences of the National Institutes of Health (NIH); and the Pennsylvania Department of Health using Tobacco CURE funds.

http://science.psu.edu/news-and-events/2018-news/Makova9-2018

Sperm donor #2757 sired at least 45 kids—now they’re connecting online

On By A.P.In UncategorizedLeave a comment

Human sperm, artwork

Half-siblings conceived with donated sperm and eggs are connecting online using DNA testing and online registries, forming extraordinarily large genetic families with dozens to hundreds of children linked to one parent, The Washington Post reports.

The modern family ties and genetic sleuthing are making it easier for donor-conceived children to learn about their backgrounds—and harder for anonymous donors to maintain anonymity. That has clearly been proven in tragic cases in which fertility doctors misled patients about their donor’s identity, even using their own sperm to sire dozens of children. But in legal, less-scandalous cases, the online connections are also highlighting the complex consequences of America’s lax regulations of the fertility industry, particularly on sperm and egg donations.

Many other countries have set legal limits on the number of children, families, or pregnancies to which one donor can contribute. Sperm donors in Taiwan can only sire one child, for instance. In Britain, they can donate to 10 families, and in China they can provide starter material for five pregnancies. But in the US, no such limits exist.

The nonprofit organization the American Society of Reproductive Medicine recommends limiting each sperm donor’s contributions to 25 births within a population of 800,000, which is about the size of San Francisco. As the Post points out, that could allow for one donor to sire more than 10,000 children across the entire country.

Though that number may seem absurdly large, the real numbers are also eye-popping. In one instance, half-siblings used online registries and DNA testing to discover that their biological father, sperm donor #2757, sired at least 29 girls and 16 boys. The half-siblings range in ages from 1 to 21 and live in eight states and four countries. Other sibling networks linked online ranged in size from dozens to nearly 200.

Such large genetic families raise concerns about half-siblings meeting unknowingly, falling in love, and having children of their own, risking genetic disorders. The vast family connections also exacerbate concerns that donors are often not required to provide medical histories and updates. There are already cases in the medical literature of half-siblings discovering each other while seeking treatments for rare genetic conditions, the Post points out.

Last month, the US Food and Drug Administration rejected a petition put forth by donor-offspring that sought to limit the number of births to which a donor could contribute. The petition also urged the FDA to track the number of each donor’s offspring and make collecting donor medical histories and updates mandatory. The FDA responded by saying that such oversight extended beyond its authority, which for now is limited to making sure that donors are screened for certain infectious diseases.

The response has infuriated families with donor-conceived children who want more regulations and transparency for donors. Meanwhile, donor-offspring continue to link up online. One daughter of donor #2757 told the Post:

“Every time I find a new sibling, I get anxiety and think to myself: when is it going to end?”

https://arstechnica.com/science/2018/09/sperm-donor-2757-sired-at-least-45-kids-now-theyre-connecting-online/

Following an outdoor lesson in nature, children were more engaged with their schoolwork, and their teachers could teach uninterrupted for almost twice as long.

On By A.P.In Uncategorized1 Comment

By Conn Hastings

A study recently published in open-access journal Frontiers in Psychology finds that 9-10 year-old children are significantly more attentive and engaged with their schoolwork following an outdoor lesson in nature. This “nature effect” allowed teachers to teach uninterrupted for almost twice as long during a subsequent indoor lesson. The results suggest that outdoor lessons may be an inexpensive and convenient way to improve student engagement in education — a major factor in academic achievement.

Scientists have known for a while that natural outdoor environments can have a variety of beneficial effects on people. People exposed to parks, trees or wildlife can experience benefits such as physical activity, stress reduction, rejuvenated attention and increased motivation. In children, studies have shown that even a view of greenery through a classroom window could have positive effects on students’ attention.

However, many teachers may be reluctant to hold a lesson outdoors, as they might worry that it could overexcite the children, making it difficult for them to concentrate on their schoolwork back in the classroom. Ming Kuo, a scientist at the University of Illinois at Urbana-Champaign, and her colleagues set out to investigate this, and hypothesized that an outdoor lesson in nature would result in increased classroom engagement in indoor lessons held immediately afterwards.

“We wanted to see if we could put the nature effect to work in a school setting,” says Kuo. “If you took a bunch of squirmy third-graders outdoors for lessons, would they show a benefit of having a lesson in nature, or would they just be bouncing off the walls afterward?”

The researchers tested their hypothesis in third graders (9-10 years old) in a school in the Midwestern United States. Over a 10-week period, an experienced teacher held one lesson a week outdoors and a similar lesson in her regular classroom, and another, more skeptical teacher did the same. Their outdoor “classroom” was a grassy spot just outside the school, in view of a wooded area.

After each outdoor or indoor lesson, the researchers measured how engaged the students were. They counted the number of times the teacher needed to redirect the attention of distracted students back to their schoolwork during the observation, using phrases such as “sit down” and “you need to be working”. The research team also asked an outside observer to look at photos taken of the class during the observation period and score the level of class engagement, without knowing whether the photos were taken after an indoor or outdoor lesson. The teachers also scored class engagement.

The team’s results show that children were more engaged after the outdoor lessons in nature. Far from being overexcited and inattentive immediately after an outdoor lesson, students were significantly more attentive and engaged with their schoolwork. The number of times the teacher had to redirect a student’s attention to their work was roughly halved immediately after an outdoor lesson.

“Our teachers were able to teach uninterrupted for almost twice as long at a time after the outdoor lesson,” says Kuo, “and we saw the nature effect with our skeptical teacher as well.”

The researchers plan to do further work to see if the technique can work in other schools and for less experienced teachers. If so, regular outdoor lessons could be an inexpensive and convenient way for schools to enhance student engagement and performance. “We’re excited to discover a way to teach students and refresh their minds for the next lesson at the same time,” says Kuo. “Teachers can have their cake and eat it too.”

Children more engaged and attentive following outdoor lesson in nature

Daycare inside a nursing home: Intergenerational Learning Center in Seattle

On By A.P.In agingLeave a comment

By Starre Vartan

Some of the most innovative ideas for the future are rooted in the past. Take the Mount Intergenerational Learning Center in Seattle. Within its walls, elderly people are teaching and spending time with preschool students.

But if it also seems odd, that’s because it’s not something you typically see in Western societies. These two groups of people tend to be almost completely isolated from each other, except maybe during holidays. Of course, that wasn’t always the case. When people lived in family groups — and in those places in the world where people still do — this was and is completely normal. And it makes sense, as both the very old and the very young seem to live at a slower, less focused, more in-the-moment state of being.

Here’s what the Mount Center says about its program: “Five days a week, the children and residents come together in a variety of planned activities such as music, dancing, art, lunch, storytelling or just visiting. These activities result in mutual benefits for both generations.”

In one of those moments of kismet, I happen to be reading Marge Piercy’s “Woman on the Edge of Time,” which is an influential feminist-utopian novel written in 1976. One of the characters from the year 2137 explains to a from-the-’70s visitor why the young children in their advanced society are being cared for by the very old: “We believe old people and children are kin. There’s more space at both ends of life. That closeness to birth and death makes makes a common concern with big questions and basic patterns. We think old people, because of their distance from the problems of their own growing up, hold more patience and can be quieter to hear what children want.”

Behind the project is Seattle University adjunct professor Evan Briggs. She told ABC News, that when the children and the residents come together there’s a “complete transformation in the presence of the children. Moments before the kids came in, sometimes the people seemed half alive, sometimes asleep. It was a depressing scene. As soon as the kids walked in for art or music or making sandwiches for the homeless or whatever the project that day was, the residents came alive.”

Like the quote from the book above, Briggs writes on her Kickstarter page that when she first saw what was happening at the Mount, she noticed: “…with neither past nor future in common, the relationships between the children and the residents exist entirely in the present. Despite the difference in their years, their entire sense of time seems more closely aligned.”

Hence the name, “Present Perfect,” for her documentary. It seems like this is an idea that might spread, an idea whose time has come — again.

Read more: http://www.mnn.com/family/family-activities/blogs/a-daycare-inside-a-nursing-home-its-pure-magic#ixzz3eZYE5Ao3

Scientific evidence that same-sex parenting does not harm children

On By A.P.In FamilyLeave a comment

There is no evidence that having same-sex parents harms children in any way, a new comprehensive review finds.

In the new review, Jimi Adams, PhD, an associate professor of health and behavioral studies at the University of Colorado Denver, said he wanted to find out if children suffered any disadvantages simply because their parents were of the same sex.
Adams’ team analyzed data from thousands of studies on the issue. The data overwhelming found that children of same-sex parents do not differ from those of heterosexual or single parents on a range of social and behavioral outcomes.

According to the research, which was published in the journal Social Science Research, by 1990 a consensus between researchers on the issue began to emerge, and by 2000 “overwhelming” consensus had been reached that same-sex parenting does not harm children.

“As same-sex marriage has been debated in courts across the country, there has been the lingering question about the effects of same-sex parenting on children,” Adams said in a university news release. “I found overwhelming evidence that scientists agree that there is not a negative impact to children of same-sex couples,” he said.

Referenc: Adams J and Light R. Scientific consensus, the law, and same sex parenting outcomes. Soc Sci Res. 2015; 53: 300-310.

http://www.sciencedirect.com/science/article/pii/S0049089X15001209

New research identifies similarity between how pigeons and human children learn equivalent of words

On By A.P.In Nature, Neuroscience, pigeon2 Comments

The more scientists study pigeons, the more they learn how their brains—no bigger than the tip of an index finger—operate in ways not so different from our own.

In a new study from the University of Iowa, researchers found that pigeons can categorize and name both natural and manmade objects—and not just a few objects. These birds categorized 128 photographs into 16 categories, and they did so simultaneously.

Ed Wasserman, UI professor of psychology and corresponding author of the study, says the finding suggests a similarity between how pigeons learn the equivalent of words and the way children do.

“Unlike prior attempts to teach words to primates, dogs, and parrots, we used neither elaborate shaping methods nor social cues,” Wasserman says of the study, published online in the journal Cognition. “And our pigeons were trained on all 16 categories simultaneously, a much closer analog of how children learn words and categories.”

For researchers like Wasserman, who has been studying animal intelligence for decades, this latest experiment is further proof that animals—whether primates, birds, or dogs—are smarter than once presumed and have more to teach scientists.

“It is certainly no simple task to investigate animal cognition; But, as our methods have improved, so too have our understanding and appreciation of animal intelligence,” he says. “Differences between humans and animals must indeed exist: many are already known. But, they may be outnumbered by similarities. Our research on categorization in pigeons suggests that those similarities may even extend to how children learn words.”

Wasserman says the pigeon experiment comes from a project published in 1988 and featured in The New York Times in which UI researchers discovered pigeons could distinguish among four categories of objects.

This time, the UI researchers used a computerized version of the “name game” in which three pigeons were shown 128 black-and-white photos of objects from 16 basic categories: baby, bottle, cake, car, cracker, dog, duck, fish, flower, hat, key, pen, phone, plan, shoe, tree. They then had to peck on one of two different symbols: the correct one for that photo and an incorrect one that was randomly chosen from one of the remaining 15 categories. The pigeons not only succeeded in learning the task, but they reliably transferred the learning to four new photos from each of the 16 categories.

Pigeons have long been known to be smarter than your average bird—or many other animals, for that matter. Among their many talents, pigeons have a “homing instinct” that helps them find their way home from hundreds of miles away, even when blindfolded. They have better eyesight than humans and have been trained by the U. S. Coast Guard to spot orange life jackets of people lost at sea. They carried messages for the U.S. Army during World Wars I and II, saving lives and providing vital strategic information.

UI researchers say their expanded experiment represents the first purely associative animal model that captures an essential ingredient of word learning—the many-to-many mapping between stimuli and responses.

“Ours is a computerized task that can be provided to any animal, it doesn’t have to be pigeons,” says UI psychologist Bob McMurray, another author of the study. “These methods can be used with any type of animal that can interact with a computer screen.”

McMurray says the research shows the mechanisms by which children learn words might not be unique to humans.

“Children are confronted with an immense task of learning thousands of words without a lot of background knowledge to go on,” he says. “For a long time, people thought that such learning is special to humans. What this research shows is that the mechanisms by which children solve this huge problem may be mechanisms that are shared with many species.”

Wasserman acknowledges the recent pigeon study is not a direct analogue of word learning in children and more work needs to be done. Nonetheless, the model used in the study could lead to a better understanding of the associative principles involved in children’s word learning.

“That’s the parallel that we’re pursuing,” he says, “but a single project—however innovative it may be—will not suffice to answer such a provocative question.”

http://now.uiowa.edu/2015/02/pigeon-power