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Category Archives: Mind Building
Scientists recreate DNA damage caused by toxins from smoking
Researchers from the University of York have recreated how toxins from smoking cause unique patterns of DNA damage. The discovery could help scientists better understand the cause of bladder cancer and the link to smoking.
The causes of bladder cancer remain largely unknown, however smoking is seen as the main risk factor for the disease.
Researchers — led by Dr Simon Baker from the Department of Biology — grew human bladder tissues in the laboratory and exposed them to a common toxin from cigarette smoke. After the tissues were damaged by the smoke toxin, the team analysed all three billion letters of the genetic code (DNA) to find a pattern of changes called a “mutational signature.”
Dr Baker said: “Mutational signatures can be used like fingerprints at a crime scene. When we look at the DNA in a cancer we can see the fingerprints of all the criminals involved in causing the damage that led to cancer.
“The DNA damaging event might be exposure to cigarette smoke or UV from the sun but it might also be an unknown event that causes cancer.”
“Our study found that the smoke toxin left its distinctive fingerprints on the DNA of bladder tissues grown in the laboratory. However, when we looked at the DNA of patients’ bladder cancers the mutational signature, of the smoke toxin, was only responsible for a small amount of the damage.
“So despite smoking being the key risk factor for bladder cancer, direct damage of the DNA by smoke toxins is unlikely to be the main reason for these cancers forming.”
It may be that the smoke toxins accelerate other DNA damaging events and attention is now focussing on a family of enzymes called “APOBEC.”
APOBEC enzymes destroy viruses by mutating their DNA as part of the body’s natural defences against infection, but recent studies suggest they might mistakenly target our own DNA in a number of cancer types. The next stage of the study will be to try and understand how and why APOBEC enzymes become activated in the cells of the bladder.
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Materials provided by University of York. Note: Content may be edited for style and length.
How hero shrews’ bizarre backbones evolved
At first glance, hero shrews don’t seem super exciting — they’re small grayish-brown mammals, related to moles and hedgehogs, and they look a little bit like chubby, long-nosed rats. But under their fur, they have some of the strangest skeletons in the animal kingdom. Hero shrews have unique interlocking backbones that make their spines insanely strong — the shrews only weigh a quarter of a pound, but there are stories that their backs can support the weight of a full-grown man standing on them. Scientists aren’t sure why these tiny animals developed such crazy backbones, but researchers looking for clues took CT scans of shrew spines to try to get a better sense of how the spines evolved.
“Hero shrews have crazy-looking spines — their vertebrae are squished flat like a pancake, and they have a bunch of extra places where they touch the vertebrae next to them. It makes a really long stiff column along their back, and there aren’t good field reports as to what this structure might be useful for,” says Stephanie Smith, a postdoctoral researcher at the Field Museum and the University of Chicago and the lead author of a new paper in Proceedings of the Royal Society B. “So we wanted to look at those vertebrae and figure out how they might be using them.”
Western scientists first became aware of hero shrews about a hundred years ago, but the Mangbetu people of the Congo Basin have long known about the shrews’ incredible strength. There’s a (maybe apocryphal) story about Mangbetu people showing a team of American and European scientists how a grown man could stand on a hero shrew’s back without hurting it. A second species of hero shrew, with a spine complexity in between that of the original hero shrew and a regular shrew, was described in 2013. But researchers haven’t been able to spot the shrews in the wild putting these backbones to good use — the shrews are hard to find, and they live in areas where political unrest makes research trips nearly impossible.
“There are two species of hero shrew, and they’re both very poorly known. We have specimens of them at the museum, but we can’t see them in action. It’s almost like studying an animal in the fossil record, where we have specimens that tell us about their anatomy, but we can’t bring a live specimen into the lab and observe it,” says Kenneth Angielczyk, a curator of paleontology at the Field Museum and the paper’s senior author.
The authors of the 2013 paper, including the Field’s late head of collections Bill Stanley, posited that the hero shrews’ thick spines might be used as a brace as the animals shifted logs and peeled apart palm stems to get at insects. But no one’s observed them doing that. All we know for sure is that the shrews’ backbones are unique.
“Their spines are arched, and when they contract their muscles to squeeze their vertebrae together, the bones interlock really tightly. When that happens, it becomes one solid block of vertebrae instead of a bunch of bendy pieces,” says Smith.
Without any live shrews to observe, Smith and Angielczyk turned to the bones in the Field Museum’s collections. They took micro-CT scans of the bones of the two known hero shrew species, as well as a “normal” shrew for comparison. These scans revealed minute details of the bones, but more importantly, they also hinted at how the bones were used in life.
“Bones contain a record, to some degree, of the forces that are acting on them during life. There are special cells in the bone that detect when pressure is put on it. They send out signals to reorganize the bone to be better at handling the forces they’re under, so you have bones responding throughout an animal’s life to habitual forces,” explains Smith. “My absolute favorite example of this was a paper where they put sheep in tall shoes, like high heels, and the different angle of pressure changed the inner structure of their leg bones.”
Armed with the knowledge that the inner structure of bone changes depending on the direction of the forces that have acted on the bone, Smith and Angielczyk tried to determine what these shrews had gotten up to. “We found that the two species of hero shrews have really, really thick, dense spongy bone inside their vertebrae. The percentage of bone is high relative to the total volume of the structure compared to other shrews,” Smith says. “That makes the bone a lot sturdier. It’s like how a chair with thick legs and crossbeams connecting those legs is sturdier than a chair with just four spindly legs and no crossbeams.”
“That’s really interesting because it says that these guys can take a lot of force compressing their spine from head to tail. And that’s the main direction that force is applied to the spine in an animal that has four legs,” continues Smith. “It doesn’t necessarily solve the question of what are they doing, but it does give us an indicator that they’re habitually experiencing strong forces in that direction.”
To sum up: hero shrew spines don’t just look tough from the outside, they’re also super dense inside, in a way that indicates that they’re able to withstand pressure from being scrunched up like an inchworm. It doesn’t confirm Stanley’s hypothesis that the shrews scrunch up and then extend their spines to wedge apart palm trunks to get at bugs — only direct observation can do that. But it does indicate that the shrew’s backbones could resist the forces such behavior would generate.
In addition to studying the forces the hero shrews were exposed to in life, Smith also helped quantify the differences between the two known species. The original hero shrew described in 1910 has a more complex spine than the new species from 2013, although the latter has a more complex spine than regular shrews. This suggests the transitional features of the 2013 species (Thor’s hero shrew) can provide information about how the 1910 shrew evolved from a slender-spined ancestor. To help quantify the differences between the shrews’ spines, Smith painstakingly counted all the little nodules and tubercles on the specimens’ vertebrae. “I think the grand total was something like 17,000,” she says. “We found that the Thor’s hero shrew was intermediate on both the inside and the outside. Because of the way that bone reacts to load, that means that it could also be functionally intermediate. But that’s just a hypothesis at this point.”
And if this all seems like a lot of time and effort thinking about shrews at a time when the world has bigger fish to fry, the researchers note that it helps answer bigger questions about the evolution of mammals.
“Small mammals experience the world differently than we do, and we don’t have all that much information about the way that being small affects their interaction with the world,” says Angielczyk. “Part of what we’re interested in is the question of how you can be a small mammal — what do you need to be effective at that and resist forces that are being applied to your body in different functional contexts. It’s something that we don’t know very much about, but it’s important, because we evolved from small mammals. Better knowledge of what it takes to be a small mammal is important for understanding a lot of weird things about mammals in general, including us.”
Smith has no plans to move on from studying shrews anytime soon. “Shrews are really interesting ecologically, and they’re so small they have almost secret powers,” she says. “They’re incredibly diverse, and I think they’re beautiful. They’re dope as hell.”
Asteroid 1998 OR2 to safely fly past Earth this week
A large near-Earth asteroid will safely pass by our planet on Wednesday morning, providing astronomers with an exceptional opportunity to study the 1.5-mile-wide (2-kilometer-wide) object in great detail.
The asteroid, called 1998 OR2, will make its closest approach at 5:55 a.m. EDT (2:55 a.m. PDT). While this is known as a “close approach” by astronomers, it’s still very far away: The asteroid will get no closer than about 3.9 million miles (6.3 million kilometers), passing more than 16 times farther away than the Moon.
Asteroid 1998 OR2 was discovered by the Near-Earth Asteroid Tracking program at NASA’s Jet Propulsion Laboratory in July 1998, and for the past two decades astronomers have tracked it. As a result, we understand its orbital trajectory very precisely, and we can say with confidence that this asteroid poses no possibility of impact for at least the next 200 years. Its next close approach to Earth will occur in 2079, when it will pass by closer — only about four times the lunar distance.
Despite this, 1998 OR2 is still categorized as a large “potentially hazardous asteroid” because, over the course of millennia, very slight changes in the asteroid’s orbit may cause it to present more of a hazard to Earth than it does now. This is one of the reasons why tracking this asteroid during its close approach — using telescopes and especially ground-based radar — is important, as observations such as these will enable an even better long-term assessment of the hazard presented by this asteroid.
Close approaches by large asteroids like 1998 OR2 are quite rare. The previous close approach by a large asteroid was made by asteroid Florence in September 2017. That 3-mile-wide (5-kilometer-wide) object zoomed past Earth at 18 lunar distances. On average, we expect asteroids of this size to fly by our planet this close roughly once every five years.
Since they are bigger, asteroids of this size reflect much more light than smaller asteroids and are therefore easier to detect with telescopes. Almost all near-Earth asteroids (about 98%) of the size of 1998 OR2 or larger have already been discovered, tracked and cataloged. It is extremely unlikely there could be an impact over the next century by one of these large asteroids, but efforts to discover all asteroids that could pose an impact hazard to Earth continue.
JPL hosts the Center for Near-Earth Object Studies (CNEOS) for NASA’s Near-Earth Object Observations Program in NASA’s Planetary Defense Coordination Office.
More information about CNEOS, asteroids and near-Earth objects can be found at:
For more information about NASA’s Planetary Defense Coordination Office, visit:
https://www.nasa.gov/planetarydefense
For asteroid and comet news and updates, follow @AsteroidWatch on Twitter:
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Materials provided by NASA/Jet Propulsion Laboratory. Note: Content may be edited for style and length.
Health24.com | Are immune-compromised kids at greater risk from Covid-19?
One of the few bright spots in the Covid-19 pandemic has been the perception that children are mostly spared from its worst effects. But what about kids already at risk of contracting serious infections due to a compromised immune system? Do they have the same protection?
“One group we always worry about when it comes to viral illnesses is immunocompromised children,” said Dr Reggie Duerst, director of the stem cell transplant programme at Children’s Hospital of Chicago. These kids are typically more at risk of known viral illnesses, such as chickenpox, common cold viruses and flu.
But, he said, because there’s so little information available on Covid-19 infections, it’s hard to know how much higher the risk might be for children with compromised immune systems.
So far, he said, the incidence of Covid-19 infections in his hospital is very low.
‘Take all precautions’
Dr Basim Asmar, chief of infectious disease at Children’s Hospital of Michigan, said it’s just not clear yet whether or not children with compromised immune systems are more likely to get Covid-19 infections. It’s also unclear if they would have more severe complications if they got an infection.
“We’re not really sure right now. We’re still learning, and every day we’re learning something new. But with other viral infections, immunocompromised children tend to have a more prolonged course,” Asmar said.
Dr Mehreen Arshad, a member of the Infectious Diseases Society of America and an assistant professor of paediatrics at Northwestern University in Chicago, agreed that there’s just not a lot of data on children and Covid-19 yet, especially kids with compromised immune systems. She said that immunocompromised children likely have less risk from Covid-19 than older adults do, but they may have more risk than children with healthy immune systems. She added it’s important to “take all precautions” to lessen the risk of infection for these children.
Which kids have a compromised immune system?
Duerst said many children who are being treated for cancer and those receiving stem cell transplants or organ transplants tend to have compromised immune systems. There are also inherited immune deficiency conditions. Children who have certain autoimmune diseases, such as rheumatoid arthritis or lupus, may take medications that dampen their immune system’s response.
Other children who might be at a higher risk include those with cystic fibrosis and other lung diseases because their lung capacity is already compromised.
A little more stringent
Among children who’ve received a stem cell transplant, the immune systems of those who get their own cells back (autologous transplant) are close to normal after a year or two, Duerst said. In kids who get stem cells from a donor (allogeneic transplant), “they are on ongoing immune suppression for three to six months, and often longer. If they have a smooth course, by two years they begin to return to normal,” he said.
Kids who’ve had an organ transplant may remain on immune-suppressing drugs for a long time, often for life.
So, what steps do parents need to take to keep these youngsters safe?
Arshad said, “I would be a little more stringent for children with compromised immunity. Stay inside as much as possible. Don’t have contact with anyone at higher risk, like grandparents, or anyone with symptoms. Don’t go to stores. Avoid crowds.”
She noted that “these families are used to taking precautions already. They may be more aware of the potential dangers.”
Asmar agreed that it’s important to follow common-sense infection prevention. And, he added, “If someone is ill within the family, even the mother or father, they should try to avoid coming in contact with the child, and should stay in a separate room.”
Hospitals relatively safe
In addition, Asmar said that children with compromised immune systems should be as up-to-date on immunisations as possible.
If your child has a compromised immune system and gets sick, Duerst said to call the physician treating the immune-compromising condition to get instructions. “There are multiple reasons you do not want to enter just any emergency room entrance,” he said. But with a number of precautions and screening in place, hospitals are “still a relatively safe place to be,” he added.
Arshad said that for more routine visits, kids can often be seen via telehealth. And if there’s something a doctor needs to see your child for, the doctor might have your child stay in the car and come out to you.
“While we’re not seeing immune-compromised children get an overwhelming number of infections, there’s no reason to be complacent,” she noted.
READ | Coronavirus hitting younger children harder than we thought
READ | Keep TB vaccine for babies, implore experts
READ | Up 50 000 US kids may be hospitalised with Covid-19 by year’s end
Image credit: iStock
Conscious Growth Club Member Portal Walkthrough
Here’s a short walkthrough video showing what the Conscious Growth Club member portal and forums look like on the inside.
I recorded this a year ago, but the look and feel of the portal and the forums are essentially the same today. The main differences from this 2019 video to what we have in 2020 include:
- We’ve added a whole new course to CGC called Stature, which includes 65 audio lessons on character sculpting.
- The coaching call times are slightly different this year. The new call times are listed on the Conscious Growth Club web page. We still offer three different times to make them accessible for each timezone.
- The May 2019 challenge was about exercise. The May 2020 challenge is called “Closing open loops,” which is about finishing incompletes and clearing items off your plate. We do new 30-day challenges every month in CGC.
- There’s another year’s worth of coaching call recordings in the portal. Each call starts with a personal growth lesson from me, so that’s 36 more lessons (we do 3 coaching calls per month).
- Several interesting subgroups have emerged in CGC this year, including a book club, a movie club, and a co-working group.
CGC’s once-a-year enrollment window is open till midnight Pacific time on May 1st. Be sure to watch the invitation video on the Conscious Growth Club page if you’d like to join us this year.
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Health24.com | Researchers caution on effects of coronavirus on male fertility
Covid-19, the disease caused by the new coronavirus (SARS-CoV-2), is largely known to cause respiratory complications such as pneumonia, shortness of breath, extreme coughing and even fatal acute respiratory distress syndrome in patients.
As scientists unpack the new coronavirus day by day, we have come to know that it may cause gastrointestinal symptoms and, in some cases, even neurological problems. But what about its effect on the rest of the body – specifically in terms of fertility and the urinary tract?
New research published in Nature Reviews Urology suggests that there is evidence that Covid-19 has implications for the urogenital tract, something which should be considered when treating Covid-19.
According to the paper, most patients with severe Covid-19 present with pneumonia-related symptoms, but some patients could develop serious urinary tract complications, including acute kidney injury (AKI), which requires continuous renal therapy.
Male reproductive system also affected
Besides kidney health, the paper states that male reproductive systems are especially vulnerable to Covid-19 infection. This has to do with dramatic changes in the sex hormones that have been observed in some patients with Covid-19.
This may lead to impaired function of the testes (gonadal function impairment).
The mechanism of Covid-19 and the reproductive system
It is already known that some viruses such as HIV, hepatitis B and C, mumps, Epstein–Barr and papilloma can cause viral orchitis, a condition where one, or both, of the male testes are inflamed. This condition may even lead to male infertility and testicular tumours.
In the case of coronavirus, testes autopsies from six patients who died from SARS – the virus which caused the 2003 outbreak – showed viral orchitis.
The researchers concluded that the new coronavirus may have the same effect. In the paper, they also refer to a previous study outcome where patients with Covid-19 showed dramatically decreased levels of testosterone in comparison to their healthy counterparts. According to them, this could be a sign that reproductive health is impaired.
What Covid-19 patients (and their doctors) should know
The researchers emphasised that those who are predisposed to kidney conditions are more at risk for Covid-19-related complications, and when they do contract the disease, health professionals should monitor their kidney health. In the case of young men contracting Covid-19 who wish to have children in the future, it is suggested they have a fertility consultation later to ensure that there is no impaired gonadal function.
READ | SA expert cautions on coronavirus treatment
READ | Coronavirus hangs around even after symptoms subside
READ | Mild coronavirus cases often appear with only gastro symptoms
Image credit: Getty Images
Health24.com | How contact lenses could impact your Covid-19 risk
Contact lens users may be at increased risk for coronavirus infection, so they need to be extra careful, an eye expert says.
“There are no confirmed cases of Covid-19 transmission by handling of contact lenses,” said David Chu, assistant professor of ophthalmology at Rutgers New Jersey Medical School, in Newark. “However, since contact lenses can cause eye irritation, wearers tend to touch their face or to rub their eyes more often, which puts them at a higher risk for acquiring infection.”
Strict hygiene is essential when wearers handle their contacts.
“They must wash their hands for a minimum of 20 seconds with soap and water, and dry their hands completely before handling contact lenses,” Chu said in a Rutgers news release.
Tears unlikely to transmit Covid-19
Standard contact lens care techniques should be adequate during the coronavirus pandemic.
But people who are more vulnerable to Covid-19 or who live with someone diagnosed with the virus should consider switching to glasses, Chu suggested.
Even though the new coronavirus has been found in human tears, it seems to be uncommon, Chu said. In case studies, patients who tested positive for the virus in their nose and throat did not have detectable levels in their tears.
It’s not clear whether tears can transmit Covid-19, but it appears unlikely, according to Chu.
Conjunctivitis (“pink eye”) is a symptom of Covid-19, but it is much less common than fever, cough, shortness of breath and diarrhoea.
“Contact lens wearers with conjunctivitis should stop using contact lenses immediately since the lens may not fit properly and may cause an abrasion on the cornea or a bacterial cornea infection, which is painful and a potentially sight-threatening complication,” Chu said.
READ | Coronavirus transmission: Chance of spreading through tears is very low
READ | Coronavirus | Concerns about if, and how it spreads in the air? Here are the facts
READ | With coronavirus a thread, stop wearing contact lenses
Image credit: iStock
