Progeria: New treatment could extend lives of children with 'premature aging' syndrome
The new treatment targets the underlying genetic cause of the disease.
30 March, 2021
Credit: Getty Images
- Progeria is an "accelerated aging" disease that causes children to die of "old age" at around 13 to 15 years.
- There are only two existing treatments, and both have unpleasant side effects.
- A promising new therapy based on biotechnology increases the lifespan of mice by over 60% and is ready for human clinical trials.
<ul class="ee-ul"></ul><p>Progeria is an extremely rare genetic disorder that causes children to present with symptoms that resemble "accelerated aging." A child with the condition takes on the appearance of an elderly person, including hair loss and thin skin. Surviving on average merely 13 to 15 years, these children often die from a heart attack or stroke, diseases that are generally associated with advanced age.</p><p>The underlying genetic cause is complex. It is the result of a single point mutation (that is, a single "letter" in the DNA is changed from G to C), and it yields an unexpected and catastrophic outcome. To understand why, an explanation of the genetics of higher organisms (like plants and animals) is in order.</p><p>Genes contain the information to encode proteins. The first step in the process of converting the information in a gene to a protein product is to transcribe ("photocopy") the gene into a molecule known as messenger RNA (mRNA). The trouble with mRNA in higher organisms is that it is riddled with garbage sequences, known as "introns," that need to be removed. The protein-encoding sequences, known as "exons," are then strung together. The process of removing introns from mRNA for the purpose of stringing together exons is called splicing. When the splicing process is complete, the mature mRNA is translated to protein.</p><p class="shortcode-media shortcode-media-rebelmouse-image">
<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTg5MTAyOC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1NjA1MjA2MX0.GXnIxjxzdTkUBrnU3XyxPnICrHhO67omD7G3WKE6xKg/img.jpg?width=980" id="0697f" width="727" height="516" data-rm-shortcode-id="59ee9316858e8445da82f8cc551a8f2b" data-rm-shortcode-name="rebelmouse-image" alt="sp">
<small class="image-media media-caption" placeholder="Add Photo Caption...">In plants and animals, mRNA "splicing" removes the introns and strings together the exons. </small><small class="image-media media-photo-credit" placeholder="Add Photo Credit...">Credit: Genomics Education Programme <a href="https://www.flickr.com/photos/genomicseducation/13063038314" target="_blank">via Flickr</a></small></p><div style="display: none;"><img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTg5MTAyOC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1NjA1MjA2MX0.GXnIxjxzdTkUBrnU3XyxPnICrHhO67omD7G3WKE6xKg/img.jpg?width=980" id="0697f" width="727" height="516" data-rm-shortcode-id="76f6bed4492f87b08701b6e8e39a95e1" data-rm-shortcode-name="rebelmouse-image" alt="sp"></div><p>As with all biological processes, splicing can go wrong. Typically, splicing occurs only at the ends of exons, so that the end of one exon is spliced to the beginning of the subsequent exon. In progeria, something very strange happens. The G to C point mutation mentioned above occurs in a gene called <em>LMNA</em> and reveals a cryptic splicing site in an inappropriate location. The outcome is the removal of a crucial exon (see "exon 11" in the figure below), which results in a deformed protein called progerin. (The normal protein, which contains exon 11, is called Lamin A.)<br></p><p><br></p><p class="shortcode-media shortcode-media-rebelmouse-image">
<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTg4MzQzOC9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY2Njk2MzEzMH0.Qy0ixPkrdBmWCGWAcj8X16HsnOXnGT53I1wfLK9yAHw/img.png?width=980" id="4df2d" width="998" height="546" data-rm-shortcode-id="38b33f3c38dce7f8d6d00b9cd0e89b77" data-rm-shortcode-name="rebelmouse-image" alt="progeria progerin lamin A ">
<small class="image-media media-caption" placeholder="Add Photo Caption...">A mutation in a gene called LMNA results in inappropriate mRNA splicing. This is the underlying genetic cause of Hutchinson-Gilford progeria syndrome. </small><small class="image-media media-photo-credit" placeholder="Add Photo Credit...">Credit: Michael R. Erdos et al., Nature Medicine, 2021.</small></p><div style="display: none;"><img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTg4MzQzOC9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY2Njk2MzEzMH0.Qy0ixPkrdBmWCGWAcj8X16HsnOXnGT53I1wfLK9yAHw/img.png?width=980" id="4df2d" width="998" height="546" data-rm-shortcode-id="c475dcc363141baf0dd336e2eb006eca" data-rm-shortcode-name="rebelmouse-image" alt="progeria progerin lamin A "></div><p>Now, a team of researchers led by Michael Erdos and Francis Collins (the current director of the National Institutes of Health) has devised a highly precise potential treatment that targets the underlying genetic cause of Hutchinson-Gilford progeria syndrome. The results are reported in <em><a href="https://www.nature.com/articles/s41591-021-01274-0" target="_blank">Nature Medicine</a></em>. </p><h2>Treating progeria</h2><p>Existing treatments are not ideal, as they both have serious side effects. The drug lonafarnib causes gastrointestinal problems, and the drug everolimus causes immunosuppression. A more targeted approach, therefore, is needed.</p><p>Erdos and his colleagues have identified a potential candidate, which comes from a class of drugs called "antisense peptide-conjugated phosphorodiamidate morpholino oligomers" (PPMOs). Essentially, it's a molecule similar to DNA or RNA with a tiny protein attached. The PPMO can be designed to recognize a very specific mRNA sequence, and in this case, it can be engineered to recognize and bind to the cryptic splice site next to exon 11. This physically blocks the cell from inappropriately splicing out exon 11 and allows it to produce a normal version of the protein (Lamin A).<br></p><p>Using mice that were genetically modified to mimic progeria, the researchers showed that their PPMO drug helped prevent the onset of progeria symptoms and extended the lives of the mice by nearly 62%.</p><p class="shortcode-media shortcode-media-rebelmouse-image">
<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTg4MzQ2OC9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYzMzkyOTEyOX0.VZnQpNh28SHGvGOXtEFZYz652eaaIjQo4WJX-mkkEjo/img.png?width=980" id="e20d5" width="1448" height="470" data-rm-shortcode-id="914e5fdb28b3000547e47b6981dcb32e" data-rm-shortcode-name="rebelmouse-image" alt="mice progeria antisense ppmo">
<small class="image-media media-caption" placeholder="Add Photo Caption...">Treatment of mice genetically modified to mimic progeria helped prevent symptom onset.</small><small class="image-media media-photo-credit" placeholder="Add Photo Credit...">Credit: Michael R. Erdos et al., Nature Medicine, 2021.</small></p><p><br></p><p class="shortcode-media shortcode-media-rebelmouse-image">
<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTg4MzQ3MC9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYyNTIyMzM3OH0.1uW0C6YC4Hcy12AIC-yp7mfLSoqf8M8LoCMyBhmvSbo/img.png?width=980" id="39b14" width="889" height="626" data-rm-shortcode-id="f09a2a6dc5566f2dca22b9e229446107" data-rm-shortcode-name="rebelmouse-image" alt="progeria mice ">
<small class="image-media media-caption" placeholder="Add Photo Caption...">Treatment of mice genetically modified to mimic progeria helped extend their lives by nearly 62%.</small><small class="image-media media-photo-credit" placeholder="Add Photo Credit...">Credit: Michael R. Erdos et al., Nature Medicine, 2021.</small></p><p>The authors believe this evidence justifies proceeding to human clinical trials. Of course, just because a drug works in a mouse does not mean it will work in a human. But this potential new treatment provides hope for those suffering from one of the world's most devastating genetic diseases.</p><p><a href="https://www.nature.com/articles/s41591-021-01274-0" target="_blank">Source</a>: Michael R. Erdos, et al. "A targeted antisense therapeutic approach for Hutchinson–Gilford progeria syndrome." Nature Medicine. Published online: 11-Mar-2021. DOI: 10.1038/s41591-021-01274-0</p>
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Johnson & Johnson COVID-19 vaccine authorized: Here's what makes it unique
Millions of doses of Johnson & Johnson's COVID-19 vaccine could be distributed as early as this week.
26 February, 2021
Credit: Rafael Henrique via Adobe Stock
- The FDA and CDC recently authorized the distribution of Johnson & Johnson's COVID-19 vaccine.
- It will soon be the third vaccine available in the U.S., the other two being vaccines produced by Pfizer-BioNTech and Moderna.
- The new vaccine has a lower efficacy rate, but clinical data suggest its highly effective at preventing hospitalization and death.
<p>A Food and Drug Administration committee is set to vote Friday (February 26) on recommending the approval of Johnson & Johnson's COVID-19 vaccine for emergency use. If the FDA's Vaccines and Related Biological Products Advisory Committee recommends approval, the next step would be getting a green light from the Centers for Disease Control and Prevention, which could authorize the distribution of up to 4 million doses of the vaccine as early as next week.</p><p>Approval from the CDC would make Johnson & Johnson's vaccine the third available vaccine in the U.S., joining those currently being distributed by Pfizer-BioNTech and Moderna. The U.S. government has already purchased 100 million doses of the Johnson & Johnson vaccine.</p><p>On Wednesday, the FDA released an <a href="https://www.fda.gov/media/146217/download" target="_blank" rel="noopener noreferrer">analysis</a> of clinical trial data on Johnson & Johnson's vaccine saying "there were no specific safety concerns identified in subgroup analyses by age, race, ethnicity, medical comorbidities, or prior SARS-CoV-2 infection," and that the vaccine was "consistent with the recommendations set forth in FDA's guidance Emergency Use Authorization for Vaccines to Prevent COVID-19."</p><p>So, what are the key differences between the three vaccines?</p>
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<p>What makes Johnson & Johnson's vaccine unique is that it's effective after just one dose, while the vaccines produced by Pfizer-BioNTech and Moderna require two doses administered over several weeks.</p><p>And unlike the other two vaccines, Johnson & Johnson's vaccine doesn't need to be frozen during shipping and storage, it just needs to be refrigerated. That's because the vaccine protects against COVID-19 by delivering coronavirus proteins to the body through a common cold virus known as adenovirus type 26. In contrast, the other two vaccines perform a similar function, but they do it through mRNA, which is more delicate and requires freezing.</p><p>Not having to freeze the single-shot vaccine will make it cheaper and easier to distribute across the country, and it could result in many more people getting vaccinated.</p><p>But it's worth noting that Johnson & Johnson's vaccine doesn't seem to be as effective as the other two vaccines. According to the FDA analysis, the vaccine is about 66 percent effective at preventing moderate to severe cases of COVID-19, "when considering cases occurring at least 28 days after vaccination." Meanwhile, clinical data show that the Pfizer-BioNTech and Moderna vaccines are about 95 percent effective at preventing severe cases of the disease.</p><img
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Credit: peterschreiber.media via Adobe Stock
<p>Still, that doesn't necessarily mean Johnson & Johnson's vaccine is inferior. The FDA analysis found that nobody who received the Johnson & Johnson vaccine was hospitalized or died due to COVID-19 (at least among cases that occurred 28 days after getting the shot).</p><p>So, while some people who receive the Johnson & Johnson vaccine may still contract coronavirus, the vaccine does seem to significantly reduce the severity of COVID-19. The same holds true for the other two vaccines: Getting the shot (or shots) won't completely protect you from the virus, but it does protect you from the disease, reducing the chances of becoming hospitalized or dying to almost zero.</p>COVID-19 vaccines and transmission
<p>But what's less clear is the extent to which the vaccines prevent the spread of the novel coronavirus. Because the vaccines don't completely protect against infection, it might be possible for a vaccinated person to spread the virus. But COVID-19 vaccines might make transmission less likely.</p><p>After all, even if a person who gets vaccinated contracts the coronavirus, the virus would have a harder time replicating in their body, because the vaccine bolsters the immune response. So, one would expect that person to "shed" less of the virus out of their mouth and nose. In short: fewer infections means less replication, less shedding, and less transmission. </p><p>That's the theory, anyway.</p><p><span></span>Scientists are still working to understand how exactly these vaccines affect transmission. But early data is promising. In a <a href="https://www.medrxiv.org/content/10.1101/2021.02.06.21251283v1.full-text" target="_blank">preprint paper published on medRxiv</a>, Israeli researchers measured the amount of coronavirus within about 2,900 people who had received the Pfizer-BioNTech vaccine.</p><p style="margin-left: 20px;">"Analyzing positive SARS-CoV-2 test results following inoculation with the BNT162b2 mRNA vaccine [the Pfizer vaccine], we find that the viral load is reduced four-fold for infections occurring 12-28 days after the first dose of vaccine," the paper said. "These reduced viral loads hint to lower infectiousness, further contributing to vaccine impact on virus spread."</p><p>But until the data on vaccines and transmission become clear, the CDC recommends that vaccinated people still wear masks and practice social distancing.<br><br><strong>UPDATE:</strong> The CDC voted on Sunday to recommend the vaccine for the United States. CDC Director Dr. Rochelle Walensky signed off on the recommendation.</p>
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Toward a disease-sniffing device that rivals a dog’s nose
Trained dogs can detect cancer and other diseases by smell. Could a device do the same?
25 February, 2021
JOEL SAGET/AFP via Getty Images
Numerous studies have shown that trained dogs can detect many kinds of disease — including lung, breast, ovarian, bladder, and prostate cancers, and possibly Covid-19 — simply through smell. In some cases, involving prostate cancer for example, the dogs had a 99 percent success rate in detecting the disease by sniffing patients' urine samples.
<p>But it takes time to train such dogs, and their availability and time is limited. Scientists have been hunting for ways of automating the amazing olfactory capabilities of the canine nose and brain, in a compact device. Now, a team of researchers at MIT and other institutions has come up with a system that can detect the chemical and microbial content of an air sample with even greater sensitivity than a dog's nose. They coupled this to a machine-learning process that can identify the distinctive characteristics of the disease-bearing samples.</p><p>The findings, which the researchers say could someday lead to an automated odor-detection system small enough to be incorporated into a cellphone, are being published today in the journal PLOS One, in a paper by Claire Guest of Medical Detection Dogs in the U.K., Research Scientist Andreas Mershin of MIT, and 18 others at Johns Hopkins University, the Prostate Cancer Foundation, and several other universities and organizations.</p><p> “Dogs, for now 15 years or so, have been shown to be the earliest, most accurate disease detectors for anything that we've ever tried," Mershin says. And their performance in controlled tests has in some cases exceeded that of the best current lab tests, he says. “So far, many different types of cancer have been detected earlier by dogs than any other technology."</p><p>What's more, the dogs apparently pick up connections that have so far eluded human researchers: When trained to respond to samples from patients with one type of cancer, some dogs have then identified several other types of cancer — even though the similarities between the samples weren't evident to humans.</p>
<p>These dogs can identify "cancers that don't have any identical biomolecular signatures in common, nothing in the odorants," Mershin says. Using powerful analytical tools including gas chromatography mass spectrometry (GCMS) and microbial profiling, "if you analyze the samples from, let's say, skin cancer and bladder cancer and breast cancer and lung cancer — all things that the dog has been shown to be able to detect — they have nothing in common." Yet the dog can somehow generalize from one kind of cancer to be able to identify the others.</p><p>Mershin and the team over the last few years have developed, and continued to improve on, a miniaturized detector system that incorporates mammalian olfactory receptors stabilized to act as sensors, whose data streams can be handled in real-time by a typical smartphone's capabilities. He envisions a day when every phone will have a scent detector built in, just as cameras are now ubiquitous in phones. Such detectors, equipped with advanced algorithms developed through machine learning, could potentially pick up early signs of disease far sooner than typical screening regimes, he says — and could even warn of smoke or a gas leak as well.</p><p>In the latest tests, the team tested 50 samples of urine from confirmed cases of prostate cancer and controls known to be free of the disease, using both dogs trained and handled by Medical Detection Dogs in the U.K. and the miniaturized detection system. They then applied a machine-learning program to tease out any similarities and differences between the samples that could help the sensor-based system to identify the disease. In testing the same samples, the artificial system was able to match the success rates of the dogs, with both methods scoring more than 70 percent.</p><p>The miniaturized detection system, Mershin says, is actually 200 times more sensitive than a dog's nose in terms of being able to detect and identify tiny traces of different molecules, as confirmed through controlled tests mandated by DARPA. But in terms of interpreting those molecules, "it's 100 percent dumber." That's where the machine learning comes in, to try to find the elusive patterns that dogs can infer from the scent, but humans haven't been able to grasp from a chemical analysis.</p>
<p>"The dogs don't know any chemistry," Mershin says. "They don't see a list of molecules appear in their head. When you smell a cup of coffee, you don't see a list of names and concentrations, you feel an integrated sensation. That sensation of scent character is what the dogs can mine."</p><p>While the physical apparatus for detecting and analyzing the molecules in air has been under development for several years, with much of the focus on reducing its size, until now the analysis was lacking. "We knew that the sensors are already better than what the dogs can do in terms of the limit of detection, but what we haven't shown before is that we can train an artificial intelligence to mimic the dogs," he says. "And now we've shown that we can do this. We've shown that what the dog does can be replicated to a certain extent."</p><p>This achievement, the researchers say, provides a solid framework for further research to develop the technology to a level suitable for clinical use. Mershin hopes to be able to test a far larger set of samples, perhaps 5,000, to pinpoint in greater detail the significant indicators of disease. But such testing doesn't come cheap: It costs about $1,000 per sample for clinically tested and certified samples of disease-carrying and disease-free urine to be collected, documented, shipped, and analyzed he says.</p><p>Reflecting on how he became involved in this research, Mershin recalled a study of bladder cancer detection, in which a dog kept misidentifying one member of the control group as being positive for the disease, even though he had been specifically selected based on hospital tests as being disease free. The patient, who knew about the dog's test, opted to have further tests, and a few months later was found to have the disease at a very early stage. "Even though it's just one case, I have to admit that did sway me," Mershin says.</p><p>The team included researchers at MIT, Johns Hopkins University in Maryland, Medical Detection Dogs in Milton Keynes, U.K., the Cambridge Polymer Group, the Prostate Cancer Foundation, the University of Texas at El Paso, Imagination Engines, and Harvard University. The research was supported by the Prostate Cancer Foundation, the National Cancer Institute, and the National Institutes of Health.</p><p>Reprinted with permission of <a target="_blank" href="http://news.mit.edu/">MIT News</a>. Read the <a target="_blank" href="https://news.mit.edu/2021/disease-detection-device-dogs-0217" rel="noopener noreferrer">original article</a>.</p>
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New study identifies 126 species that could host coronavirus
The study suggests scientists are underestimating the number of animal species that could generate the next novel coronavirus.
19 February, 2021
Credit: Pixabay
- The novel coronavirus that causes COVID-19 is a product of different coronaviruses recombining in animal species.
- A new study suggests that hundreds of animal species may harbor multiple types of coronaviruses, meaning recombination events could be more likely than previously thought.
- The authors noted that their results could help improve surveillance programs to mitigate the risks associated with a future novel coronavirus.
<p>A new study highlights hundreds of mammal species that could contract multiple coronaviruses, including SARS-CoV-2, and therefore become sources of new coronaviruses. Published in <a href="https://www.nature.com/articles/s41467-021-21034-5?utm_medium=affiliate&utm_source=commission_junction&utm_campaign=3_nsn6445_deeplink_PID100052172&utm_content=deeplink#Abs1" target="_blank">Nature Communications</a>, the research suggests that novel coronaviruses could emerge from many more animal species than scientists have so far observed.</p><p>Coronaviruses comprise a large family of viruses. Humans are known to contract only seven coronaviruses, including SARS-CoV, MERS-CoV, and SARS-CoV-2, all of which can cause severe disease or death. But coronaviruses can circulate more widely in the animal kingdom, and within it scientists have identified hundreds of unique strains.</p><p>Some animals can become infected with multiple coronaviruses at the same time. When this occurs, genes from the different viruses can combine and replicate, creating a novel coronavirus. This natural process is called recombination, and it's what produced SARS-CoV-2, the novel coronavirus that causes COVID-19. </p><p>So, in which animal species might the next novel coronavirus originate through recombination?</p>
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Wardeh et al.
<p class="caption"><em>Predicted hosts are grouped by order (inner circle). Middle circle presents probability of association between host and SARS-CoV-2 (grey scale indicates predicted associations with probability in range > 0.5 to ≤0.75. Red scale indicates predicted associations with probability in range > 0.75 to <0.9821. Blue to purple scale present indicates associations with probability ≥ 0.9821). Yellow bars represent number of coronaviruses (species or strains) observed to be found in each host. Blue stacked bars represent other coronaviruses predicted to be found in each host by our model. Predicted coronaviruses per host are grouped by prediction probability into three categories (from inside to outside): ≥0.9821, >0.75 to <0.9821 and >0.5 to ≤0.75.<br></em><br>To answer that, the researchers behind the recent study created a computer model to predict which species have the highest risk of being "reservoirs" for coronaviruses. Using data from GenBank, a National Institutes of Health database, the team compared 411 coronaviruses with 876 mammalian species that are known to contract coronaviruses.</p><p>The model predicted that each coronavirus species can infect, on average, more than 12 types of mammalian hosts. Meanwhile, the results suggested that each mammalian host can contract roughly five different types of coronavirus.</p><p>In terms of recombination, some mammalian species pose outsized threats. The study noted that the domestic pig presents a high risk because it is known to harbor many diverse coronaviruses.</p><p style="margin-left: 20px;">"Given the large number of predicted viral associations presented here, the pig's close association to humans, its known reservoir status for many other zoonotic viruses, and its involvement in genetic recombination of some of these viruses, the pig is predicted to be one of the foremost candidates an important recombination host," the authors wrote.</p><img
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Credit: Pixabay
<p>The study also identified species in which SARS-CoV-2 might combine with other coronaviruses. These included the lesser Asiatic yellow bat, the common hedgehog, the European rabbit, chimpanzees, the African green monkey and domestic cats (which are already known to contract SARS-CoV-2, though there's no evidence that cats or other pets can spread the novel coronavirus to humans).<br></p><p>Also on that list was the dromedary camel, a "known host of multiple coronaviruses and the primary route of transmission of MERS-CoV to humans." It'd be especially concerning if MERS-CoV and SARS-CoV-2 recombined, considering the former is highly deadly and the latter is highly contagious.</p>Improved surveillance programs
<p>Still, many factors must align for coronaviruses to merge and generate a novel coronavirus, and just because an animal is vulnerable to multiple viruses doesn't mean those viruses will recombine. But the team behind the study noted that scientists are likely underestimating the number of animals that could generate novel coronaviruses, and that the results can help inform surveillance programs for at-risk species.</p><p style="margin-left: 20px;">"Such information could help inform prevention and mitigation strategies and provide a vital early warning system for future novel coronaviruses," the authors wrote.</p>
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Catnip is for both pleasure and protection, according to a new study
The main bioactive compound in catnip seems to protect cats from mosquitoes. It might protect humans, too.
23 January, 2021
Credit: Pixabay
- For centuries, humans have observed that cats exhibit strange behaviors when exposed to catnip and silver vine.
- A new study examined how the main bioactive compound in these plants affects cats' opioid systems and protects them against mosquito bites.
- The findings suggest that the compound nepetalactol could be used to develop new mosquito repellents for humans.
<p>Why does catnip have such a strong effect on cats? For at least 300 years, humans have observed that when cats encounter the plant, the majority behave as if they're high, becoming playful and hyperactive before reliably slumping into a nap. But catnip also elicits another strange behavior: Cats rub their faces and bodies against the plant, seemingly trying to cover their fur with it.</p><p>A new study proposes cats do this because catnip acts as a chemical defense against mosquitos. </p><p>Published in <a href="https://advances.sciencemag.org/content/7/4/eabd9135" target="_blank">Science Advances</a>, the findings suggest that cats evolved specific olfactory receptors to detect the bioactive compounds in catnip, which produces euphoria while protecting them from irritating bites and diseases. This protection might've helped the stealthy animals better stalk and ambush prey.</p><p>The findings shed light not only on feline behavior, but also on how nepetalactol—the main bioactive component of catnip and silver vine—might be used to protect humans against insects.</p>
<img
class="rm-lazyloadable-image rm-shortcode" type="lazy-image"
data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTUyNjUxMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY2Nzk2MzQ2MX0.pukD0O6rrYJD7Y5zp7myD84MoVBRdUuh79qV4zBu7uo/img.jpg?width=980"
id="abb77"
width="800"
height="1199"
data-rm-shortcode-id="917b46e20611b152090ea0df3d9b3960" data-rm-shortcode-name="rebelmouse-image" alt="Nepeta cataria" />
Nepeta cataria, commonly known as catnip
Credit: Johann Georg Sturm (Painter: Jacob Sturm) via WikiPedia/Public Domain
<p>In the study, researchers from Iwate University in Japan exposed nepetalactol-laced paper to different types of felids, including domestic and feral cats, a leopard, two jaguars, and two lynx. The team also exposed nepetalactol to dogs and mice, but only the cats elicited the expected behavioral response.</p><p>To find out why cats react uniquely to nepetalactol, the researchers measured the animals' endorphin levels before and after they were exposed to the substance. The results showed that nepetalactol raised endorphin levels in cats.</p><p>But when cats were given drugs that blocked opioid receptors, their endorphin levels didn't rise, and their behavior didn't change. This suggests that cats' "μ-opioid system is stimulated by an increase in endogenous β-endorphin secretion when olfactory neurons are activated by these iridoids," the team wrote.</p>Nepetalactol as a mosquito repellent
<p>To test the efficacy of nepetalactol as a mosquito repellant, the researchers anesthetized two groups of cats. For one group, the researchers applied nepetalactol to the cats' heads. The other group was left untreated to serve as a control. The researchers then exposed the cats to Asian tiger mosquitos and counted the number of times the insects bit each group.</p><p>The results showed that the group treated with nepetalactol was much less likely to get bitten, sometimes by as much as 50 percent. The same proved true in a "more natural" experiment, in which cats were allowed to rub their faces on the plants themselves.</p><p style="margin-left: 20px;">"This is convincing evidence that the characteristic rubbing and rolling response functions to transfer plant chemicals that provide mosquito repellency to cats," the team wrote.</p>The world's deadliest animal
<p>While the researchers don't fully understand why nepetalactol activates the μ-opioid system in cats, they think the compound could help humans avoid mosquito bites. After all, some of the study contributors have applied for a patent covering the use of nepetalactol as an insect repellent. Gizmodo <a href="https://gizmodo.com/cats-love-catnip-because-it-protects-them-from-mosquito-1846092518" target="_blank" rel="noopener noreferrer">reports</a> that the researchers even tried applying the compound to their arms, which seemed to prevent mosquito bites.</p><p>For thousands of years, humans have aimed to protect themselves from mosquitos. The Egyptian queen Cleopatra was said to sleep surrounded by a mosquito net. The Romans used vinegar mixtures. And Mississippians turned to the American beautyberry plant. </p><p>Today, DEET is the most widely used mosquito repellent, but it's slightly toxic and can cause side effects, including seizures, though rarely. Developing better mosquito repellents could save many lives. The World Mosquito Program <a href="https://www.worldmosquitoprogram.org/en/learn/mosquito-borne-diseases#:~:text=Nearly%20700%20million%20people%20contract,more%20than%20one%20million%20deaths." target="_blank">reports</a> that mosquito-borne illnesses like malaria and yellow fever affect more than 700 million annually and kill approximately one million. </p>
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