Publisher Health

Describing the genetic diversity of human populations is essential to improve our understanding of human diseases and their geographical distribution. However, the vast majority of genetic studies have been focused on populations of European ancestry, which represent only 16% of the global population. Scientists at the Institut Pasteur, Collège de France, and CNRS have looked at understudied human populations from the South Pacific, which are severely affected by a variety of diseases, including vector-borne infectious diseases such as Zika virus, dengue, and chikungunya, and metabolic diseases such as obesity and diabetes. Using genome sequencing of 320 individuals, the scientists have investigated how human populations have biologically adapted to the environments of the Pacific islands and how this has affected their current state of health. This study has also revealed hitherto unsuspected aspects of the history of human settlement in this region. This work is published in the April 14th, 2021 issue of Nature.
An international consortium of scientists organized by Etienne Patin (CNRS/Institut Pasteur) and Lluis Quintana-Murci (Collège de France/Institut Pasteur) was set up to characterize the genetic diversity of populations in the South Pacific, a region full of contrasts with its myriad islands that have been settled at very different time periods.
Indeed, shortly after humans left Africa, they settled Near Oceania (Papua-New-Guinea, the Bismarck Archipelago, and the Solomon Islands) approximately 45,000 years ago, while the rest of the Pacific, known as Remote Oceania (Vanuatu, the Wallis and Futuna Islands, Polynesia, etc.), remained uninhabited. It was only approximately 40,000 years later that Remote Oceania was peopled: it is currently accepted that a group of humans left Taiwan 5,000 years ago — a migration known as the ‘Austronesian expansion’ — passed through the Philippines, Indonesia, and the already-inhabited Near Oceanian islands to eventually settle Remote Oceania for the first time.
En route to these remote lands, the ancestors of South Pacific populations met with groups of archaic humans, with whom they interbred. While 2-3% of modern-day Oceanian populations’ genetic material is inherited from Neanderthals (which all populations outside Africa also possess), up to 3% of their genomes is also inherited from Denisovans (relatives of Neanderthals thought to have originated in Asia). It was already known that modern humans inherited beneficial mutations from Neanderthals via admixture, which improved their ability to adapt to their environment, including resistance to viral infections (Cell, 2016 ). In this study published today, scientists from the Human Evolutionary Genetics Unit (Institut Pasteur/CNRS ) in collaboration with various laboratories in France , Germany, Sweden, Switzerland, China, and Taiwan have sought to shed light on how ancient admixture helped Pacific populations to adapt to their specific island environments, including any pathogens encountered.
Historical events traced using genetics
Based on whole-genome-sequencing of over 320 individuals from Taiwan, the Philippines, the Bismarck Archipelago, the Solomon Islands, Santa Cruz Islands, and Vanuatu, this work published in the Nature journal has helped tracing the history of the human settlement of Oceania. First, the scientists have dated the settlement of the various islands of Near Oceania back to approximately 40,000 years, thus confirming archaeological records. They have also demonstrated that this initial settlement was followed by a period of genetic isolation between islands. “Our results confirm that humans were able to cross the seas to reach new lands from an early stage. However, they also suggest that these voyages were relatively infrequent at this distant period in history,” explains Etienne Patin, a CNRS scientist within the Human Evolutionary Genetics Unit at the Institut Pasteur. Moreover, the results of the study reveal a major reduction in the size of these populations just before the settlement.

An advisory committee for the Centers for Disease Control and Prevention will meet on Wednesday afternoon to discuss whether the Johnson & Johnson Covid-19 vaccine should remain paused while a possible link to rare blood clots is investigated.The emergency meeting follows the Food and Drug Administration’s announcement on Tuesday that it was studying six cases of rare and severe blood clots in women aged 18 to 48, one of whom died. All of the women had received the Johnson & Johnson vaccine before developing the clots, though it is unclear whether the vaccine is responsible. As of Tuesday, more than seven million people in the United States have received the shot, and another 10 million doses have been shipped out to the states, according to C.D.C. data.Following the call from federal health agencies, all 50 states, Washington, D.C., and Puerto Rico on Tuesday quickly paused or recommended that providers pause the administration of the vaccine. The U.S. military, federally run vaccination sites, and a host of private companies, including CVS, Walgreens, Rite Aid, Walmart and Publix also paused the injections.The Advisory Committee on Immunization Practices, or ACIP, is a panel of independent experts who advise the C.D.C. on its vaccine policies. At the meeting, the experts will be reviewing and debating the data from the six cases, and listening to comments from the public, before taking a vote on how to proceed. They could vote to recommend that the pause continues, for example, or to specify that it should apply only to a certain age or sex.Federal officials said on Tuesday that the pause might last only a few days, though it depended on what officials learned in the investigation. They said that the pause will give officials more time to alert doctors that patients who have these rare blood clots should not be given the drug heparin, the standard treatment that doctors administer for typical clots, and also provide time to determine whether there are any more cases.The clotting disorder of concern in the vaccine recipients is different — and much rarer — than typical blood clots, which develop in hundreds of thousands of people every year. The six women had not only clotting in the brain, but a notably low level of platelets, parts of the blood that help form normal clots.The U.S. surgeon general, Dr. Vivek Murthy, reiterated on Wednesday that the pause in Johnson & Johnson vaccinations gives public health officials a chance to investigate the cases and discuss them with health care professionals. He added that pauses are common when new vaccines and drugs are rolled out.“We’re just doing the due diligence we need to do to make sure everything is safe so we can continue with our vaccination efforts,” Dr. Murthy said on “CBS This Morning.”The committee’s assessment will be crucial at a time when the nation is racing to vaccinate as many people as possible to curb the steady accumulation of cases, particularly as worrisome variants gain traction. Some public health experts were disappointed in the F.D.A.’s recommendation to suspend the Johnson & Johnson vaccine, arguing that preventing these extremely rare side effects was not worth the trade-off of slowing the vaccination campaign and potentially eroding the public’s trust of vaccines in general.Madeleine Ngo contributed reporting.

Can it affect mammograms or the timing of fertility treatments? What side effects should you look out for? Experts weigh in.News that six women developed a rare blood clotting disorder after receiving Johnson & Johnson’s Covid-19 vaccine has prompted new questions about whether vaccines affect women differently than men, and whether there are special considerations that women should take into account when getting vaccinated. We spoke with a few experts to learn what women should know as they become eligible to get their shots.We don’t yet know if the blood clots affect women more than men. Federal health agencies on Tuesday recommended that practitioners pause administering the Johnson & Johnson vaccine after a half-dozen women developed a rare blood clotting disorder about two weeks after vaccination. The recipients were between the ages of 18 and 48; one woman died and a second was hospitalized in critical condition.But it is not clear if the clotting was caused by the vaccines or whether women are necessarily more often affected. In Europe, it initially appeared that women were at greater risk for blood clots associated with the AstraZeneca-Oxford vaccine, which has not been authorized for use yet in the United States, but it turned out that more women were getting the vaccine overall in some countries. British regulators now say that they don’t have evidence to say whether men or women are more likely to be affected by blood clots.Anyone who has a severe headache, abdominal pain, shortness of breath or leg pain after receiving the Johnson & Johnson vaccine should call their health care provider.Getting vaccinated can change the way your mammogram looks.Coronavirus vaccinations can cause enlarged lymph nodes in the armpit that will show up as white blobs on mammograms. This type of swelling is a normal reaction to the vaccine and will typically occur on the same side as the arm where the shot was given, said Dr. Geeta Swamy, a maternal-fetal medicine specialist and a member of the American College of Obstetricians and Gynecologists’s Covid vaccine group. It usually only lasts for a few weeks.But the vaccine’s effect on mammograms can be concerning to radiologists, she added, because “if someone had breast cancer we might see enlarged lymph nodes as well.”Because this type of swelling could be mistaken as a sign of cancer, the Society of Breast Imaging recommends trying to schedule your routine mammogram before your first Covid-19 vaccine dose or at least one month after your second vaccine dose.“I am particularly eager to get the word out to all the patients undergoing surveillance after successful prior treatment of cancer,” Dr. Constance D. Lehman, who has written about the problem and is the chief of breast imaging at Massachusetts General Hospital, told The New York Times in March. “I can’t imagine the anxiety of getting the scan and hearing, ‘We found a node that is large. We don’t think it’s cancer but can’t tell.’ Or worse, ‘We think it might be cancer.’”But say you are getting a diagnostic mammogram because of a suspicious lump or other symptoms of breast cancer disease or you are someone who had been treated for breast cancer and needs to get regular exams; in those cases, “do not delay,” Dr. Swamy said. You should keep your current mammogram appointment as well as your vaccination appointment, and tell your radiologist the date that you received the vaccine.Fertility patients should coordinate the timing of their vaccine with their clinic.Fertility patients who are scheduled for procedures like egg retrieval, embryo transfer or intrauterine insemination are advised to avoid getting a Covid vaccine within three days before and three days after the procedure, according to the American Society for Reproductive Medicine.That’s because patients undergoing surgical procedures could develop vaccine-related side effects like fever or chills that might make it difficult for doctors to know if a post-surgical infection is brewing. In addition, many medical providers may not allow a patient who is experiencing Covid-like symptoms into their facility, even if it’s likely that the symptoms are from a vaccine and their Covid-19 test is negative.If you manage to get a vaccine appointment and you are scheduled to undergo a fertility procedure, tell your fertility doctor right away so that you can plan any surgical procedures, testing or treatment.All timing issues aside, getting vaccinated is the right thing to do, experts say. Based on all of the reassuring evidence to date, when it comes to fertility or pregnancy, “there are no known safety concerns with the vaccine,” said Dr. Sigal Klipstein, a reproductive endocrinologist in Chicago who is a member of the American Society for Reproductive Medicine Covid-19 Task Force.“Women who contract Covid during pregnancy are at increased risk for more severe disease compared to women who get Covid when they’re not pregnant,” she added.The American College of Obstetricians and Gynecologists said in a statement on Tuesday that for the time being, pregnant and postpartum women who want to be vaccinated should be encouraged to get either the Pfizer-BioNTech or Moderna shots, not the Johnson & Johnson vaccination.If one of your vaccine shots is scheduled during the “two-week wait” — the period of time between ovulation and your expected period when the embryo would implant in the uterus — don’t worry, even if you develop side effects from the vaccine.“Fever should not interfere with implantation,” Dr. Klipstein said.Try not to take any painkillers ahead of time in anticipation of vaccine-related symptoms like fever or headache, because it is believed to dampen your body’s immune response. After the vaccine, it is OK to take acetaminophen, which is considered safe during pregnancy. Women who are pregnant or potentially pregnant should avoid ibuprofen, Dr. Klipstein said..css-1xzcza9{list-style-type:disc;padding-inline-start:1em;}.css-rqynmc{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:0.9375rem;line-height:1.25rem;color:#333;margin-bottom:0.78125rem;}@media (min-width:740px){.css-rqynmc{font-size:1.0625rem;line-height:1.5rem;margin-bottom:0.9375rem;}}.css-rqynmc strong{font-weight:600;}.css-rqynmc em{font-style:italic;}.css-yoay6m{margin:0 auto 5px;font-family:nyt-franklin,helvetica,arial,sans-serif;font-weight:700;font-size:1.125rem;line-height:1.3125rem;color:#121212;}@media (min-width:740px){.css-yoay6m{font-size:1.25rem;line-height:1.4375rem;}}.css-1dg6kl4{margin-top:5px;margin-bottom:15px;}.css-16ed7iq{width:100%;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center;padding:10px 0;background-color:white;}.css-pmm6ed{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;}.css-pmm6ed > :not(:first-child){margin-left:5px;}.css-5gimkt{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:0.8125rem;font-weight:700;-webkit-letter-spacing:0.03em;-moz-letter-spacing:0.03em;-ms-letter-spacing:0.03em;letter-spacing:0.03em;text-transform:uppercase;color:#333;}.css-5gimkt:after{content:’Collapse’;}.css-rdoyk0{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;-webkit-transform:rotate(180deg);-ms-transform:rotate(180deg);transform:rotate(180deg);}.css-eb027h{max-height:5000px;-webkit-transition:max-height 0.5s ease;transition:max-height 0.5s ease;}.css-6mllg9{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;position:relative;opacity:0;}.css-6mllg9:before{content:”;background-image:linear-gradient(180deg,transparent,#ffffff);background-image:-webkit-linear-gradient(270deg,rgba(255,255,255,0),#ffffff);height:80px;width:100%;position:absolute;bottom:0px;pointer-events:none;}#masthead-bar-one{display:none;}#masthead-bar-one{display:none;}.css-1pd7fgo{background-color:white;border:1px solid #e2e2e2;width:calc(100% – 40px);max-width:600px;margin:1.5rem auto 1.9rem;padding:15px;box-sizing:border-box;}@media (min-width:740px){.css-1pd7fgo{padding:20px;width:100%;}}.css-1pd7fgo:focus{outline:1px solid #e2e2e2;}#NYT_BELOW_MAIN_CONTENT_REGION .css-1pd7fgo{border:none;padding:20px 0 0;border-top:1px solid #121212;}.css-1pd7fgo[data-truncated] .css-rdoyk0{-webkit-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);}.css-1pd7fgo[data-truncated] .css-eb027h{max-height:300px;overflow:hidden;-webkit-transition:none;transition:none;}.css-1pd7fgo[data-truncated] .css-5gimkt:after{content:’See more’;}.css-1pd7fgo[data-truncated] .css-6mllg9{opacity:1;}.css-1rh1sk1{margin:0 auto;overflow:hidden;}.css-1rh1sk1 strong{font-weight:700;}.css-1rh1sk1 em{font-style:italic;}.css-1rh1sk1 a{color:#326891;-webkit-text-decoration:underline;text-decoration:underline;text-underline-offset:1px;-webkit-text-decoration-thickness:1px;text-decoration-thickness:1px;-webkit-text-decoration-color:#ccd9e3;text-decoration-color:#ccd9e3;}.css-1rh1sk1 a:visited{color:#333;-webkit-text-decoration-color:#ccc;text-decoration-color:#ccc;}.css-1rh1sk1 a:hover{-webkit-text-decoration:none;text-decoration:none;}Women are questioning whether the vaccine affects their menstrual cycle.Some women say they have observed changes in the flow or timing of their period after getting vaccinated.But so far this is purely anecdotal.“It’s unlikely that the Covid vaccine would affect menstrual cycles, and there’s no plausible biological mechanism by which this would occur. However, there is little data on this topic,” Dr. Klipstein said.Kathryn Clancy, an associate professor of anthropology at the University of Illinois, generated hundreds of responses on Twitter after saying that her period was heavier than usual after her first dose of the Moderna vaccine. She is now collaborating with Katharine Lee, a postdoctoral research scholar at Washington University in St. Louis, to survey women on short-term vaccine side effects related to the menstrual cycle. Their online survey has been available for less than a week and has so far drawn more than 19,000 responses, Dr. Lee said on Wednesday.Periods can be affected by a multitude of factors, including stress, thyroid dysfunction, endometriosis or fibroids. If you have questions about your menstrual cycle, be sure to speak with your doctor.Women appear to have more side effects after vaccination than men.A study by the Centers for Disease Control and Prevention, published in February, examined the Pfizer-BioNTech and Moderna vaccines and found that 79 percent of the side effects reported to the agency came from women, even though only 61 percent of the vaccines had been administered to women.It could be that women are more likely to report side effects than men, said Dr. Sabra L. Klein, a professor of molecular microbiology and immunology at the Johns Hopkins Bloomberg School of Public Health. Or, she added, women might be experiencing side effects to a greater degree. “We’re not sure which it is,” she said.If women are in fact having more side effects than men, there might be a biological explanation: Women and girls can produce up to twice as many antibodies after receiving flu shots and vaccines for measles, mumps and rubella (M.M.R.) and hepatitis A and B, probably because of a mix of factors, including reproductive hormones and genetic differences. A study found that over nearly three decades, women accounted for 80 percent of all adult allergic reactions to vaccines. Similarly, the C.D.C. reported that most of the anaphylactic reactions to Covid-19 vaccines, while rare, have occurred among women. And in a letter published in the New England Journal of Medicine describing the experiences of people who had redness, itching and swelling that began four to 11 days after the first shot of the Moderna vaccine, 10 of the 12 patients were women. It is not clear, however, whether women are more prone to the problem.If you have mild side effects like headache or a low fever, it’s actually a good thing, Dr. Klein said, because it means your immune system is ramping up. A lack of side effects, however, does not mean the vaccine isn’t working. You can share your symptoms or concerns via the C.D.C.’s V-safe app, which records symptoms and provides health check-ins after vaccinations. Medically significant reports sent using V-safe will be followed up by a call from a representative.

An advisory committee for the Centers for Disease Control and Prevention will meet on Wednesday afternoon to discuss whether the Johnson & Johnson Covid-19 vaccine should remain paused while a possible link to rare blood clots is investigated.The emergency meeting follows the Food and Drug Administration’s announcement on Tuesday that it was studying six cases of rare and severe blood clots in women aged 18 to 48, one of whom died. All of the women had received the Johnson & Johnson vaccine before developing the clots, though it is unclear whether the vaccine is responsible. As of Tuesday, more than seven million people in the United States have received the shot, and another 10 million doses have been shipped out to the states, according to C.D.C. data.Following the call from federal health agencies, all 50 states, Washington, D.C., and Puerto Rico on Tuesday quickly paused or recommended that providers pause the administration of the vaccine. The U.S. military, federally run vaccination sites, and a host of private companies, including CVS, Walgreens, Rite Aid, Walmart and Publix also paused the injections.The Advisory Committee on Immunization Practices, or ACIP, is a panel of independent experts who advise the C.D.C. on its vaccine policies. At the meeting, the experts will be reviewing and debating the data from the six cases, and listening to comments from the public, before taking a vote on how to proceed. They could vote to recommend that the pause continues, for example, or to specify that it should apply only to a certain age or sex.Federal officials said on Tuesday that the pause might last only a few days, though it depended on what officials learned in the investigation. The pause was called for in part because patients who have these rare blood clots should not be given the standard treatment that doctors prescribe for typical clots.The clotting disorder of concern in the vaccine recipients is different — and much rarer — than typical blood clots, which develop in hundreds of thousands of people every year. The six women had not only clotting in the brain, but a notably low level of platelets, parts of the blood that help form normal clots.The committee’s assessment will be crucial at a time when the nation is racing to vaccinate as many people as possible to curb the steady accumulation of cases, particularly as worrisome variants gain traction. Some public health experts were disappointed in the F.D.A.’s recommendation to suspend the Johnson & Johnson vaccine, arguing that preventing these extremely rare side effects was not worth the trade-off of slowing the vaccination campaign and potentially eroding the public’s trust of vaccines in general.

Humans have a uniquely high density of sweat glands embedded in their skin — 10 times the density of chimpanzees and macaques. Now, researchers at Penn Medicine have discovered how this distinctive, hyper-cooling trait evolved in the human genome. In a study published today in the Proceedings of the National Academy of Sciences, researchers showed that the higher density of sweat glands in humans is due, to a great extent, to accumulated changes in a regulatory region of DNA — called an enhancer region — that drives the expression of a sweat gland-building gene, explaining why humans are the sweatiest of the Great Apes.
“This is one of the clearest examples I’ve ever seen of pinpointing the genetic basis for one of the most extreme and distinctively human evolutionary traits as a whole,” said the study’s senior author, Yana Kamberov, PhD, an assistant professor of genetics at Penn Medicine. “This kind of research is important not only because it shows how evolution actually works to produce species diversity but also because it gives us access into human biology that is often not possible to gain in other ways, essentially by learning from tweaking the biological system in a way that is actually beneficial, without breaking it.”
Scientists broadly assume that humans’ high density of sweat glands, also called eccrine glands, reflects an ancient evolutionary adaptation. This adaptation, coupled with the loss of fur in early hominins, which promoted cooling through sweat evaporation, is thought to have made it easier for them to run, hunt, and otherwise survive on the hot and relatively treeless African savannah, a markedly different habitat than the jungles occupied by other ape species.
Kamberov found in a 2015 study that the expression level of a gene called Engrailed 1 — EN1 in humans — helps determine the density of eccrine glands in mice. EN1 encodes a transcription factor protein that, among many other functions, works during development to induce immature skin cells to form eccrine glands. Because of this property, Kamberov and colleagues hypothesized that perhaps one way in which humans could have built more sweat glands in their skin is to evolve genetic changes that increased the production of EN1 in the skin.
The activity of a gene is often affected by nearby regions of DNA called enhancer regions, where factors that activate the gene can bind and help drive the gene’s expression. In the study, Kamberov and her team identified an enhancer region called hECE18 that boosts the production of EN1 in skin, to induce the formation of more eccrine glands. The researchers showed that the human version of hECE18 is more active than that of ape or macaque versions, which would in turn drive higher levels of EN1 production.
Kamberov and her colleagues also teased apart the individual mutations that distinguish human hECE18, showing why some of them boost EN1 expression — and showing that rolling back those mutations to the chimp version of hECE18 brings the enhancer activity down to chimp levels.
Prior studies of evolved human-specific traits, such as language, generally have tied such traits to complex genetic changes involving multiple genes and regulatory regions. In contrast, the work from Kamberov and her team suggest that the human “high-sweat” trait evolved at least in part through repeated mutations to just one regulatory region, hECE18. This means that this single regulatory element could have repeatedly contributed to a gradual evolution of higher eccrine gland density during human evolution.
While the study is mainly a feat of basic biology that shines a light on human evolution, it also should have some long-term medical relevance, Kamberov said.
“Severe wounds or burns often destroy sweat glands in skin, and so far we don’t know how to regenerate them — but this study brings us closer to discovering how to do that,” she said. “The next step in this research would be to uncover how the multiple activity enhancing mutations in hECE18 interact with each other to increase EN1 expression and to use these biologically key mutations as starting points to figure out what DNA-binding factors actually bind at these sites. Basically, this provides us with a direct molecular inroad to discover the upstream factors that by activating EN1 expression get skin cells to start making sweat glands.”

A potential treatment for dementia and epilepsy could look to reduce the amounts of a toxic gas in the brain has been revealed in a new study using rat brain cells.
The research published in Scientific Reports today [Wednesday 14 April] shows that treatments to reduce levels of hydrogen sulfide (H2S) in the brain may help to ward off damage caused by the gas. By testing rat brain cells, the team of scientists from the University of Reading, University of Leeds and John Hopkins University in the USA found that H2S is involved in blocking a key brain cell gateway that helps the brain to communicate effectively.
Dr Mark Dallas, Associate Professor in Cellular Neuroscience at the University of Reading said:
“This is an exciting finding as it gives us new insights about the role of hydrogen sulfide in various brain diseases, such as dementia and epilepsy. There has been growing interest in the effect of hydrogen sulfide on the brain and this study shows how important the implications of its build-up on proper brain functioning may be.
“We saw that hydrogen suldife acts to disrupt the normal functioning of potassium channels. These channels regulate electrical activity across the connections between brain cells, and when these channels are blocked from working properly we see overexcitable brain cells which we believe is leading to nerve cell death.
“The implication for potential treatments is particularly exciting because finding drugs that target hydrogen sulfide production in our brains may have a host of benefits for diseases, and there are clear links between hydrogen sulfide build -up and other warning signs for diseases such as Alzheimer’s.”
In the study, cells taken from rat brains were charged with a H2S donor molecule, and then brain cell electrical signals were monitored. The resulting exposure to H2S increased the level of activity in brain cells, and the research was able to establish that the effect was specifically controlled by the potassium channel tested.
The team were also able to identify which part of the potassium channel was allowing this effect from H2S. They used a mutated form of the potassium channel, which has already been shown to protect nerve cells from a host of toxic stimuli, including amyloid beta and found that the mutation was resistant to the effect of H2S that was seen in natural cells.
The specific mutated channel now holds particular interest for research into Alzheimer’s Disease, given the protective benefits against amyloid beta which is also implicated in dementia.
Dr Moza Al-Owais, Research Fellow at the University of Leeds said:
“This exciting study demonstrates the growing evidence that gasotransmitters play an important role as signalling molecules in the regulation of the physiological processes underlying Alzheimer’s disease, which are relatively poorly understood, opening new avenues for investigation and drug discovery.”
Story Source:
Materials provided by University of Reading. Note: Content may be edited for style and length.

Compared to newborns conceived traditionally, newborns conceived through in vitro fertilization (IVF) are more likely to have certain chemical modifications to their DNA, according to a study by researchers at the National Institutes of Health. The changes involve DNA methylation — the binding of compounds known as methyl groups to DNA — which can alter gene activity. Only one of the modifications was seen by the time the children were 9 years old.
The study was conducted by Edwina Yeung, Ph.D., and colleagues in NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). Previous studies by the research team found no differences in growth and development for this group.
“Our study found only small differences in DNA methylation at birth and these were not seen in early childhood,” Dr. Yeung said. “When considered along with our previous studies finding no differences in children’s growth and development, our current study should be reassuring to couples who have conceived with fertility treatments and to those considering these methods.”
IVF consists of collecting eggs and sperm, fertilizing the eggs in a lab, and then transferring the resulting embryo or embryos into the uterus. Another technique, intracytoplasmic sperm injection (ICSI), consists of injecting a sperm cell directly into the egg before placing the resulting embryo into the uterus.
Methylation changes were not associated with two other fertility treatments, ovulation induction (drug treatment to release the egg from the ovary) and intrauterine insemination (insertion of semen directly into the uterus).
According to a national report in 2018, almost 75,000 IVF-conceived infants (2.0% of all infants) were born in the United States. Of these, approximately 76% were conceived with ICSI. Another study found that 3 to 7% of births resulted from ovulation induction and intrauterine insemination.
When methyl groups are added to a gene, the gene is switched off and does not produce a protein. Methyl groups are added and removed from DNA throughout life, as genes are alternately switched on and off. Changes in methylation may occur in any step of IVF. These include exposure to hormones needed to bring the eggs to maturity so they can be collected or exposure to the culture medium in which the eggs are fertilized and embryos develop.
Previous studies have found associations between IVF and certain rare disorders. However, many of these studies were small and their results inconsistent. Also, many of the studies were conducted before ICSI was in widespread use.
For the current study, researchers evaluated data on DNA methylation differences in children beginning at birth and when they were 8 to 10 years old. The children were born in New York State from 2008 to 2010 and more than 70% of IVF birth were with ICSI.
Of the newborns, 157 were conceived with fertility treatments and 520 were conceived without treatments. Newborns conceived with IVF were more likely to have lower methylation levels in some parts of their DNA. The researchers did not find any methylation changes for newborns conceived by ovulation induction or intrauterine insemination.
Among the 152 children who provided DNA samples at 8 to 10 years old, 23 were conceived with IVF and 34 with ovulation induction or intrauterine insemination. For children conceived with IVF, lower methylation levels were seen for only one region, in the GNAS gene, which has been found in some previous studies but not others.
The study authors called for more research on how variations in fertility treatments could contribute to methylation differences in children, such as variations in the medium used to culture embryos.

A team of UBC Okanagan researchers has determined that the type of fats a mother consumes while breastfeeding can have long-term implications on her infant’s gut health.
Dr. Deanna Gibson, a biochemistry researcher, along with Dr. Sanjoy Ghosh, who studies the biochemical aspects of dietary fats, teamed up with chemistry and molecular biology researcher Dr. Wesley Zandberg. The team, who conducts research in the Irving K. Barber Faculty of Science, explored the role of feeding dietary fat to gestating rodents to determine the generational effects of fat exposure on their offspring.
“The goal was to investigate how maternal dietary habits can impact an offspring’s gut microbial communities and their associated sugar molecule patterns which can be important in immune responses to infectious disease,” says Dr. Gibson, who studies gut health and immunity as well as causes of acute or chronic diseases like inflammatory bowel disease.
Their study suggests that the type of fat consumed during breastfeeding could differentially impact an infant’s intestinal microbial communities, immune development and disease risk.
The three main classes of fatty acids include saturated (SFA), found in meats and dairy products, monounsaturated fats (MUFA), found in plant-based liquid oils, and polyunsaturated fatty acids (PUFAs), found in some nuts, fish and shellfish. PUFAs are further characterized as either n-3 PUFAs or n-6 PUFAs, based on the number and positions of double bonds in the acyl chain.
Previous research has determined both n-3 PUFAs and n-6 PUFAs can have a negative impact on intestinal infections such as Enteropathogenic E. coli, Clostridium difficile, salmonella and gastrointestinal illnesses from eating poorly prepared or undercooked food or drinking contaminated water. In contrast, diets rich in MUFAs and SFAs have been shown to be largely protective against these infections.

SharecloseShare pageCopy linkAbout sharingimage copyrightEPADenmark has ceased giving the Oxford-AstraZeneca Covid vaccine amid concerns about rare cases of blood clots, the first country to do so entirely.The move is expected to delay the country’s vaccination programme by several weeks.Drug watchdog the European Medicines Agency last week announced a possible link with clots but said the risk of dying of Covid-19 was much greater.Several European countries have previously suspended the jab briefly.Most have now resumed vaccinations with AstraZeneca for older population groups.On Tuesday, the US, Canada and the European Union paused the Johnson & Johnson vaccine for similar reasons.Blood clot is ‘very rare AstraZeneca side effect’What you need to know about vaccine safetyThe EU’s vaccine roll-out has been criticised by the World Health Organization (WHO) for being too slow, and there are concerns this latest delay could throw it into further turmoil. Both vaccines work by a similar method, known as adenoviral vectors.Danish officials said that all 2.4 million doses of the AstraZeneca vaccine would be withdrawn until further notice.”The Danish Health Authority has decided to continue the vaccination against Covid-19 without the vaccine from AstraZeneca,” it said in a statement.However, it said it could not rule out using it again at another time.Is Europe’s Oxford jab decision-making flawed?Is the Oxford AstraZeneca vaccine safe?Almost one million people in Denmark have been vaccinated, with approximately 150,000 of them receiving the AstraZeneca jab.The Pfizer/BioNTech and Moderna vaccines are also in use.Denmark was first country to postpone use of the AstraZeneca vaccine in March. It was followed by numerous other European countries.

People who tended to be sedentary were far more likely to be hospitalized, and to die, from Covid than those who exercised regularly.More exercise means less risk of developing severe Covid, according to a compelling new study of physical activity and coronavirus hospitalizations. The study, which involved almost 50,000 Californians who developed Covid, found that those who had been the most active before falling ill were the least likely to be hospitalized or die as a result of their illness.The data were gathered before Covid vaccines became available and do not suggest that exercise can substitute in any way for immunization. But they do intimate that regular exercise — whether it’s going for a swim, walk, run or bike ride — can substantially lower our chances of becoming seriously ill if we do become infected.Scientists have known for some time that aerobically fit people are less likely to catch colds and other viral infections and recover more quickly than people who are out of shape, in part because exercise can amplify immune responses. Better fitness also heightens antibody responses to vaccines against influenza and other illnesses.But infections with the novel coronavirus are so new that little has been known about whether, and how, physical activity and fitness might affect risks for becoming ill with Covid. A few recent studies, however, have seemed encouraging. In one, which was published in February in The International Journal of Obesity, people who could walk quickly, an accepted gauge of aerobic fitness, developed severe Covid at much lower rates than sluggish walkers, even if the quick striders had obesity, a known risk factor for severe disease. In another study of older adults in Europe, greater grip strength, an indicator of general muscle health, signaled lowered risks for Covid hospitalizations.But those studies looked at indirect measures of people’s aerobic or muscular fitness and not their actual, everyday exercise habits, so they cannot tell us if getting up and moving — or staying still — changes the calculus of Covid risks.So, for the new study, which was published Tuesday in the British Journal of Sports Medicine, researchers and physicians at Kaiser Permanente Southern California, the University of California, San Diego, and other institutions decided to compare information about how often people exercised with whether they wound up hospitalized this past year because of Covid.The Kaiser Permanente health care system was well suited for this investigation, because, since 2009, it has included exercise as a “vital sign” during patient visits. In practice, this means doctors and nurses ask patients how many days each week they exercise, such as by walking briskly, and for how many minutes each time, then add that data to the patient’s medical record.Now, the researchers drew anonymized records for 48,440 adult men and women who used the Kaiser health care system, had their exercise habits checked at least three times in recent years and, in 2020, had been diagnosed with Covid-19. The researchers grouped the men and women by workout routines, with the least active group exercising for 10 minutes or less most weeks; the most active for at least 150 minutes a week; and the somewhat-active group occupying the territory in between.The researchers gathered data, too, about each person’s known risk factors for severe Covid, including their age, smoking habits, weight, and any history of cancer, diabetes, organ transplants, kidney problems and other serious, underlying conditions.Then the researchers crosschecked numbers, with arresting results. People in the least-active group, who almost never exercised, wound up hospitalized because of Covid at twice the rate of people in the most-active group, and were subsequently about two-and-a-half times more likely to die. Even compared to people in the somewhat-active group, they were hospitalized about 20 percent more often and were about 30 percent more likely to die..css-1xzcza9{list-style-type:disc;padding-inline-start:1em;}.css-rqynmc{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:0.9375rem;line-height:1.25rem;color:#333;margin-bottom:0.78125rem;}@media (min-width:740px){.css-rqynmc{font-size:1.0625rem;line-height:1.5rem;margin-bottom:0.9375rem;}}.css-rqynmc strong{font-weight:600;}.css-rqynmc em{font-style:italic;}.css-yoay6m{margin:0 auto 5px;font-family:nyt-franklin,helvetica,arial,sans-serif;font-weight:700;font-size:1.125rem;line-height:1.3125rem;color:#121212;}@media (min-width:740px){.css-yoay6m{font-size:1.25rem;line-height:1.4375rem;}}.css-1dg6kl4{margin-top:5px;margin-bottom:15px;}.css-16ed7iq{width:100%;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center;padding:10px 0;background-color:white;}.css-pmm6ed{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;}.css-pmm6ed > :not(:first-child){margin-left:5px;}.css-5gimkt{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:0.8125rem;font-weight:700;-webkit-letter-spacing:0.03em;-moz-letter-spacing:0.03em;-ms-letter-spacing:0.03em;letter-spacing:0.03em;text-transform:uppercase;color:#333;}.css-5gimkt:after{content:’Collapse’;}.css-rdoyk0{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;-webkit-transform:rotate(180deg);-ms-transform:rotate(180deg);transform:rotate(180deg);}.css-eb027h{max-height:5000px;-webkit-transition:max-height 0.5s ease;transition:max-height 0.5s ease;}.css-6mllg9{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;position:relative;opacity:0;}.css-6mllg9:before{content:”;background-image:linear-gradient(180deg,transparent,#ffffff);background-image:-webkit-linear-gradient(270deg,rgba(255,255,255,0),#ffffff);height:80px;width:100%;position:absolute;bottom:0px;pointer-events:none;}#masthead-bar-one{display:none;}#masthead-bar-one{display:none;}.css-1pd7fgo{background-color:white;border:1px solid #e2e2e2;width:calc(100% – 40px);max-width:600px;margin:1.5rem auto 1.9rem;padding:15px;box-sizing:border-box;}@media (min-width:740px){.css-1pd7fgo{padding:20px;width:100%;}}.css-1pd7fgo:focus{outline:1px solid #e2e2e2;}#NYT_BELOW_MAIN_CONTENT_REGION .css-1pd7fgo{border:none;padding:20px 0 0;border-top:1px solid #121212;}.css-1pd7fgo[data-truncated] .css-rdoyk0{-webkit-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);}.css-1pd7fgo[data-truncated] .css-eb027h{max-height:300px;overflow:hidden;-webkit-transition:none;transition:none;}.css-1pd7fgo[data-truncated] .css-5gimkt:after{content:’See more’;}.css-1pd7fgo[data-truncated] .css-6mllg9{opacity:1;}.css-1rh1sk1{margin:0 auto;overflow:hidden;}.css-1rh1sk1 strong{font-weight:700;}.css-1rh1sk1 em{font-style:italic;}.css-1rh1sk1 a{color:#326891;-webkit-text-decoration:underline;text-decoration:underline;text-underline-offset:1px;-webkit-text-decoration-thickness:1px;text-decoration-thickness:1px;-webkit-text-decoration-color:#ccd9e3;text-decoration-color:#ccd9e3;}.css-1rh1sk1 a:visited{color:#333;-webkit-text-decoration-color:#ccc;text-decoration-color:#ccc;}.css-1rh1sk1 a:hover{-webkit-text-decoration:none;text-decoration:none;}Of the other common risk factors for severe disease, only advanced age and organ transplants increased the likelihood of hospitalization and mortality from Covid more than being inactive, the scientists found.“Being sedentary was the greatest risk factor” for severe illness, “unless someone was elderly or an organ recipient,” says Dr. Robert Sallis, a family and sports medicine doctor at the Kaiser Permanente Fontana Medical Center, who led the new study. And while “you can’t do anything about those other risks,” he says, “you can exercise.”Of course, this study, because it was observational, does not prove that exercise causes severe Covid risks to drop, but only that people who often exercise also are people with low risks of falling gravely ill. The study also did not delve into whether exercise reduces the risk of becoming infected with coronavirus in the first place.But Dr. Sallis points out that the associations in the study were strong. “I think, based on this data,” he says, “we can tell people that walking briskly for half an hour five times a week should help protect them against severe Covid-19.”A walk — or five — might be especially beneficial for people awaiting their first vaccine, he adds. “I would never suggest that someone who does regular exercise should consider not getting the vaccine. But until they can get it, I think regular exercise is the most important thing they can do to lessen their risk. And doing regular exercise will likely be protective against any new variants, or the next new virus out there.”