Three English Biochemists Unravel DNA to Unlock the ...



Explainer: What are mitochondria and how did we come to have them?By?Steven Zuryn, The ConversationWe’ve probably all heard of mitochondria, and we may even remember learning in school that they are the “powerhouses of the cell” — but what does that actually mean, and how did they evolve? To answer this question, we have to go back about 2 billion years to a time when none of the complexity of life as we see it today existed.Where Did Mitochondria Come From?Our primordial ancestor was a simple single-celled creature, living in a long-term rut of evolutionary stagnation. Then something dramatic happened — an event that would literally breathe life into the eventual evolution of complex organisms. One of the cells engulfed another and enslaved it as a perpetual source of energy for its host.The increase in available energy to the cell powered the formation of more complex organisms with multiple cells, eyes and brains. Slowly, the two species became intertwined — sharing some of their DNA and delegating specific cellular tasks — until, eventually, they became firmly hardwired to each other to form the most intimate of biological relationships. Two separate species became one.These energy slaves are the mitochondria, and there are hundreds or even thousands of them inside every one of your cells (with the exception of red blood cells) and in every other human alive. They still resemble their bacterial origin in appearance, but we can no longer exist without them, nor they without us. The evolutionary explosion powered by mitochondria is evident by the fact they are found in every complex multicellular organism that has ever existed, from giraffes to palm trees, mushrooms and dinosaurs.As vestiges of their ancient origin, mitochondria still have their own genome (although some of their DNA has been transferred to our genome). It’s alien in appearance and composition when compared with our own nuclear genome (the DNA inside each of your cell’s nuclei that contains about 20,000 genes). In fact, our nuclear genome shares more in common with that of a sea sponge than with the mitochondrial genome inside our own cells.0000Unlike the nuclear genome, the mitochondrial genome is small (containing just 37 genes), circular and uses a different DNA code. The mitochondrial genome slinks its way across generations by stowing away within mitochondria harbored in each egg, and as such, is passed down from the mother only. This is different to the nuclear genome, half of which is inherited from your father and the other half from your mother.What Do The Mitochondria Do?The mitochondrial genome is vital for the mitochondria’s main role: burning the calories we eat with the oxygen we breathe to generate the energy to power all of our biological processes. But this amazing source of energy is not without its cost.Like any powerhouse, mitochondria produce toxic by-products. Free radicals (highly reactive oxygen molecules with an odd number of electrons that can cause aging and health problems) can be created by accidents that happen during energy production.So in essence, mitochondria power and imperil our cells.Because the mitochondrial genome is in close proximity to the source of free radicals, it’s more susceptible to their damaging effects. And the mitochondrial genome undergoes replication thousands of times more than the nuclear genome, simply because you have so many in each cell. Making copies of copies introduces mistakes.A combination of these two effects results in the mitochondrial genome mutating up to 50 times faster than the nuclear genome, which is meanwhile kept safely in the nucleus. These mutations can be passed down to maternal offspring, causing devastating metabolic disorders in the next generation.What Happens When Something Goes Wrong?Only as recently as 1988 was the first disease caused by such a mutation in the mitochondrial genome identified. Now, we know about many such disorders, called mitochondrial diseases, which can be traced to mutations in the mitochondrial genome. These diseases can manifest at any age and result in a wide range of symptoms including hearing loss, blindness, muscle wasting, stroke-like episodes, seizures and organ failure.These diseases are currently incurable. But multiple lines of investigation are currently underway to treat and prevent transmission to subsequent generations.Despite this, during life, it’s inevitable that mutations will occur in the mitochondrial genome in an individual’s neurons, muscle and all other cells. Compelling work now suggests that the accumulation of these mistakes may contribute to the progressive nature of late-onset degenerative diseases such as Alzheimer’s and Parkinson’s.The health of this seemingly alien genome is inextricably linked to that of our own bodies. As we come to grips with mitochondria’s importance in disease, we continue to uncover the intimate secrets of a 2-billion-year relationship that has given complex life to the planet.Steven Zuryn is a group leader at the Queensland Brain Institute at the University of Queensland in Australia.Three English Biochemists Unravel DNA to Unlock the Mystery of LifeBy?Cynthia Stokes Brown, Big History Project, adapted by Newsela staff In 1953, three English biochemists helped unlock the mystery of life by determining the structure of the DNA molecule. Found in all life on Earth, DNA contains the information by which an organism regenerates its cells and passes traits to its offspring.Charles Darwin had successfully proposed the theory of natural selection, but he didn’t understand how parents pass characteristics to their offspring. Slight changes when passing down traits made evolution possible.By the middle of the twentieth century, this was still not well understood. There were major breakthroughs earlier in the century in physics, such as Albert Einstein’s Theory of Relativity, and atomic bombs that used nuclear fusion.After World War II, scientists began trying to understand the physical basis (atomic and molecular) of biology. In the 1950s, biochemists realized that DNA delivered the instructions for copying a new organism. A yard of DNA — deoxyribonucleic acid — is folded and packed into the nucleus of every cell in pairs called “chromosomes.”The parts of DNADNA has three parts:?a type of sugar called “deoxyribose,”?a phosphate responsible for its acidity, and?four kinds of bases — adenine (A), thymine (T), guanine (G), and cytosine (C).These four bases seemed too simple to pass on all the information needed to create a new organism. Biochemists didn’t understand DNA’s structure and how it worked. However, these four bases combine like letters of an alphabet to describe complex variations in genetic traits.The question became how to study the DNA molecule. Biochemists wanted to understand its structure. They thought this was the key to understanding how it coded the instructions for copying a new organism.They began taking X-ray images of crystals of DNA, believing that its crystallization meant it must have a regular structure. The pattern of the X-rays bouncing off atoms gave information about their location in the molecule.One of the pioneers of this technique, called “X-ray crystallography,” was Linus Pauling, who worked at the California Institute of Technology, in Pasadena. In the early 1950s, Pauling, a prominent chemist, seemed likely to unlock the mystery of life, since he had already concluded that the general shape of DNA must be a helix, or spiral.The race is onThe victory, however, went to three people working in England, in one of the great scientific races of all time. One, Rosalind Franklin, was working at the University of London. The other two, James Watson and Francis Crick, were friends and lab mates some 50 miles away at Cambridge University, where they worked cooperatively and shared their ideas.Franklin was from a wealthy, influential family in London. After earning a PhD from Cambridge in physical chemistry, she began to study DNA at the University of London, in 1951. Franklin became extremely skilled in X-ray crystallography. She was able to produce clear and accurate images of DNA crystals by using fine-focus X-ray equipment and pure DNA samples.Over at Cambridge, Crick was 35, working on his PhD in the crystallography of proteins. He had grown up in a small English village.Watson was only 23 in 1951. He had grown up in Chicago, performed on the national radio show “Whiz Kids,” entered the University of Chicago at age 15, and secured his doctorate from the University of Indiana at just 22. He was at the Cambridge lab to learn crystallography.Between 1951 and 1953, Franklin examined her precise X-ray diffraction images. She reasoned that 1) DNA takes two forms (shorter-dryer and longer-wetter), 2) the sugar-phosphate backbones must be on the outside, and 3) the molecule looks the same upside down or right side up.In late 1952, she recorded an especially clear X-ray image. Her colleague, Maurice Wilkins, showed the image to Watson in 1953 without telling her or asking her permission.A spiral shapeWhen Watson saw the image, he knew at once that DNA had to be a helix. He returned to his lab to begin making models out of sheet metal and wire.Watson and Crick built models to try to visualize DNA. How many strands did the helix have? Which direction did the strands run? Were they on the inside or the outside? How were the four chemical bases arranged?Franklin believed more X-ray images of better quality would answer the questions. But Watson and Crick knew they were racing against Pauling. They felt making models would speed up the answers.Using paper models and combining them in different ways, they visualized a structure that solved the puzzle. If two of the bases were bonded in pairs (G with C), they took up the same space as the other pair (A with T). Hence, they could be arranged like steps on a spiral staircase inside of two strands of sugar-phosphates running in opposite directions.These insights occurred to Crick and Watson in February 1953. They announced at lunch in their usual pub that they had found the secret of life.The news gets outThe April 25, 1953, issue of?Nature?published Crick and Watson’s article, “A Structure for Deoxyribose Nucleic Acid.” Wilkins and Franklin, who both accepted Crick and Watson’s solution, wrote accompanying articles.By the 1960s, scientists had accepted the double helix as the structure of DNA. In 1962, Wilkins, Watson, and Crick received the Nobel Prize in medicine/physiology for their work.Franklin could not share in the prize. She had passed away in 1958 of ovarian cancer. She was just 37. Franklin had a family history of cancer, but her exposure to X-rays may have contributed to her death.In any case, she may not have had the chance for the award had she been alive. Crick and Watson never told Franklin that they had used her images. In?Nature, Watson and Crick only mentioned her briefly. She wasn’t credited in Watson’s book about the discovery,?The Double Helix?(1968).It wasn’t until much later that Watson finally admitted in public that he and Crick could not have found the double helix in 1953 without Franklin’s experimental work. If she had survived, would she have been acknowledged and shared in the prize?In their 1953 article, Watson and Crick did not discuss how DNA copies itself.Five weeks after their first article in?Nature, Crick and Watson published another article proposing the idea that, to make a copy, the double helix unzips, or separates, into two strands. Each strand is a backbone of sugar-phosphates with the four bases attached in some sequence.Then the cell uses each strand as a template to assemble another DNA strand from free-floating complementary bases: A picks up T, while C picks up G. This would result in two identical DNA molecules, one a copy of the other. Occasional mistakes in copying enable evolution to occur and each organism to be unique. This idea has been confirmed, while the means for carrying it out have proved to be quite complex.Crick continued his research in England until 1976, when he moved to the Salk Institute for Biological Studies in California, where he died in 2004. Watson returned to the United States, researching at Harvard from 1956 to 1976. He helped establish the Human Genome Project in the early 1990s and served as president of the Cold Spring Harbor Laboratory in New York, until his retirement in 2007.A possible solution to the world's antibiotic crisis could lie in the dirtBy?Washington Post, adapted by Newsela staffOne of the biggest medical discoveries happened by accident.?One day, a British scientist named Alexander Fleming returned from vacation. He realized that he had forgotten to put one of his petri dishes away when he was gone. When he returned, it was covered in a bacteria-killing mold. He had accidentally discovered penicillin, the world's first antibiotic.?Ninety years later, the world faces an antibiotic crisis. Superbugs have evolved resistance to dozens of drugs in doctors' arsenals, leading to infections that are increasingly difficult to treat. Global deaths from antibiotic-resistant infections are predicted to hit 10 million a year by 2050. So in labs around the world, scientists are racing against time to cultivate new microbe-destroying molecules. Unfortunately, most of the obvious solutions have already been discovered.?Now it is time to look at other ways of finding antibiotics. Instead of growing antibiotics in a petri dish, microbiologist Sean Brady hopes to find them in the ground."Every place you step, there's 10,000 bacteria, most of which we've never seen," said Brady, a professor at Rockefeller University in New York. Many of these bacteria behave in ways that aren't yet understood and produce molecules that haven't been seen before.The Cure Could Be Right Under Our Feet"Our idea is, there's this reservoir of antibiotics out in the environment we haven't accessed yet," Brady said.That idea is beginning to pay off. In a study published February 12 in the journal Nature Microbiology, he and his colleagues report the discovery of a new class of antibiotic extracted from unknown microorganisms living in the soil. This class, which they call malacidins, kills several superbugs — including ones that cause dreaded staph infections like pneumonia — without getting resistance.You won't find this antibiotic at your pharmacy next week, Brady cautioned. It takes years for a new molecule to be developed, tested and approved for distribution. However, its discovery is proof of a powerful principle, he said: A world of potentially useful untapped biodiversity is still waiting to be discovered.Though antibiotics are prized for their ability to combat the microbes that make humans sick, most of them actually come from bacteria. For example, streptomycin, which has been used to treat tuberculosis and plague, is produced by the bacterium Streptomyces griseus. This microbe was originally found in the dirt of a New Jersey farm field.Bacteria Have Evolved Over TimeBacteria have been fighting one another for billions of years — far, far longer than humans have been around — so it's hardly surprising that they have evolved all the best weapons. Yet the vast majority of these microbes don't grow well under controlled laboratory conditions, making them difficult to study."Maybe, using that simple culture-based approach, we've missed most of the chemistry that are produced by bacteria," Brady said.It would be better to get interesting molecules directly from the environment. And these days, scientists can do just that by using metagenomics. This is the study of genetic material directly from the environment. These techniques allow for a lot of genetic material to be organized at the same time.?For this study, Brady's team cloned vast quantities of DNA from hundreds of soil samples contributed by citizen scientists across the country. Then, they sorted through the material in search of interesting sequences."Most of what's there is completely unknown, and that's the future," Brady said.The Power Of MalacidinsHe and his team were looking specifically for a known gene associated with the production of calcium-dependent antibiotics — molecules that attack bacterial cells, but only when calcium is around. It's thought that the existence of such an "on-off" switch may make it harder for microbes to evolve resistance. Because of this, the gene for calcium dependence might serve as a sign that a much longer sequence is controlling the production of antibiotics. It'd be like if you were reading a cookbook and came across instructions for making pie crust — that might be a flag you'd found a recipe for pie.Having identified a sequence containing the calcium-dependence gene, the researchers cloned it and injected it into a microbe that can be cultured or grown. Soon enough, those microbes were making chemicals called malacidins. When applied to cuts in the skin of rats suffering from a bacteria, the previously unknown molecule successfully sterilized the wounds. The bacterium didn't show signs of resistance, even after three weeks of exposure.According to Brady, malacidins work by interfering with the process that bacteria use to build their cell walls. Human cells rely on a different process, so the antibiotic isn't toxic in people.He and his team don't know what species the molecules come from, but they don't need to — they already have the genetic blueprint for building it. "The effort now is to scale it," he said.A Possible Medical BreakthroughTwo years ago, Brady launched a company called Lodo Therapeutics, which aims to accelerate the discovery process. Ultimately, it may produce new medications that can be used to treat disease.Researchers elsewhere are using metagenomics to seek out new antibiotics in ocean water and insect guts. Meanwhile, the same technique has been applied to city sewers and polluted lakes to reveal the vast extent of antibiotic resistance.Speaking to the Los Angeles Times, Northeastern University microbiologist Kim Lewis noted that Brady's team "used a clever approach to mine for antibiotics."But Lewis, who was not involved in the research, pointed out that Brady's team will need to continue identifying new DNA signatures associated with antibiotics for their technique to keep working. "Now we need to say, 'You guys can do even better.'"Explainer: What is a virus?By?Allen Cheng, The Conversation, adapted by Newsela staffIt may seem fairly basic, but experts are still arguing over whether viruses should be considered a form of life.The diversity of viral infections is immense. Viruses cause everything from common cold (rhinoviruses) to Ebola, the deadly disease that has killed thousands in Africa, and warts (papillomavirus), and from influenza to smallpox. Many viruses can cause cancer, and the hepatitis B virus is a known cause of liver cancer.Viruses show some of the characteristics of living organisms. They have DNA, which controls how every part of a living creature develops and functions. They also evolve by natural selection and create copies of themselves. However, most biologists argue they aren’t alive because they can’t replicate by themselves.To say that viruses are small is an understatement. If the human genome were “War and Peace,” the 1,200-page novel by Leo Tolstoy, the average bacterium would have a genome of about a page or two. On this scale, the influenza virus is about two words, while the smallest virus, circovirus, would be merely a letter or two.Essentially, viruses are snippets of genetic code that take over the living cells to replicate themselves. They then escape the cell and spread. There is a good reason why a “computer virus” is called what it is. Even a virus' envelope – the coating that many viruses have to protect their contents – comes from the cells of its hosts.Vaccines Are Developed To Stop VirusesSome viruses that cause human diseases can be killed by vaccines.The word vaccine comes from the Latin word for “cow." It is based on an observation by English scientist and doctor Edward Jenner that milkmaids were protected from smallpox after they were exposed to cowpox, a cow disease that was similar to smallpox but not as severe. From this came the idea that infection with a closely-related but less dangerous virus could protect against serious disease.It was then found that even inactivated viruses were able to enable the immune system to remember and protect from infection on a later date. An inactivated virus is one that has been grown and then killed. Scientists then added these?inactivated viruses into the vaccines that we get as shots when we visit the doctor.?Vaccines have weak viruses inside them, that are either living or?dead,?but can't reproduce themselves. When we get shot with vaccines it helps our bodies get used to them. Then, our bodies can defend themselves if we catch a live or strong virus.The best vaccines have even resulted in the eradication of diseases, such as smallpox. Hopefully, in the near future, polio and measles will also become illnesses of the past.Breaking Ground With Antiviral TreatmentsWhile antibiotics for treating bacterial infection were developed in the 1940s, antiviral treatments are a much more recent development.Most antiviral medication attempts to block one or more points in the viral replication cycle. Many antiviral medications used to treat HIV and herpes simplex (which causes cold sores), for instance, stop the replication mechanism itself.Some antivirals interfere with the way viruses use to enter or exit host cells. Others activate the immune system to seek and destroy cells infected by viruses.Mega-, Mimi- Or Truc?Viruses can infect all living organisms, even bacteria, and they seem to be everywhere.J. Craig Venter, the biologist and entrepreneur, was one of the first to sequence the human genome (interestingly, his own). He sailed around the world in his yacht and took samples of seawater as he went. When his team examined the samples, they found an incredible diversity of new viruses, with about 10 million copies of viruses per milliliter of water.The recent discovery of new, very large viruses has also blurred the lines between what is and is not life. In 2003, the Mimivirus was found inside an amoeba in England. It was named the “microbe-mimicking virus” because it was visible under a microscope and had a genome that rivaled small bacteria.The largest known virus is the Pandoravirus, found in a pond in Melbourne, Australia. Its genome is nearly as complex as of a small parasite.These recent discoveries have prompted a reconsideration of the nature and classification of life. Didier Raoult, the French biologist who led the team that discovered Mimivirus, has even suggested reclassifying complex organisms such as giant viruses as “truc.” This is French for “stuff,” as well as being an acronym for “things resisting [un]complete classification” — in other words, the “too hard” basket.Are the seawater viruses the soup from which we evolved? More research may give answers to these and other interesting questions. Whatever the case, it is clear that these tiny genetic parasites will always be problems for us to deal with.Allen Cheng is an Associate Professor of Infectious Diseases Epidemiology at Monash University in Australia.The big "if" about stem cell therapy for injured athletesBy?Associated Press, adapted by Newsela staffC.J. Nitkowski had nothing to lose in spring 2011. The tendons and muscles in his left shoulder, that he'd relied on during his 10 years as a major league pitcher, were in tatters. He was 38 and his fastball traveled a Little League-worthy 50 miles per hour.Surgery and the following lengthy rehabilitation would have killed his career. So Nitkowski paid $3,000 to have stem cells taken from his waist, separated and then injected back into his shoulder. Stem cell therapy is a new medical procedure that is supposed to help repair damaged tissue that can't heal by itself. Stem cells from one part of the body are used to treat an illness or disease in another."A Last Shot""I look at it as a last shot," Nitkowski said.The "boost" he felt after the procedure helped him sign a minor-league deal with the New York Mets in 2012. Though he never made it back to the majors before retiring in 2013, Nitkowski is confident he'd wrung out every last ounce of talent. While not an advocate for stem cell therapy, as one of the few athletes who have gone public on the treatment, he understands why active players approach him about it."I can't give a recommendation," Nitkowski said. "I can only tell my story. I feel like, based on what I believe, that (stem cell therapy) would almost become like maintenance ... if they generate tissue."No Absolute Lab ResultsThat's a big "if," particularly for professional athletes and the teams that pay them millions. Several years after Nitkowski's procedure, a lot of questions about stem cell therapy remain unanswered.Why? Because even though studies still haven't proven for sure what it can and can't do, there is plenty of hype.This is why players and agents are paying so much attention to it."They want the cutting edge. Anything that is cutting edge that can get their guys a couple more years in the league," said Dr. Jim Bradley, orthopedic surgeon for the NFL's Pittsburgh Steelers. "If I was an agent, I'd want the same thing."Yet while Bradley is excited about its potential, he still spends a fair amount of time explaining what exactly stem cell therapy does. Adult stem cells are undifferentiated cells found throughout the body. Because they are undifferentiated, they don't yet have a role. They can still divide rapidly and differentiate into other cell types to help repair tissue. The belief is that stem cells can serve as reinforcements to an injured muscle or joint.But nearly all evidence is anecdotal — no absolute lab results show it works. That has done little to dampen interest."Everybody wants answers right now and you can't have them right now," Bradley said.At least not in the United States, where medical regulation is more restrictive than elsewhere. To avoid scrutiny from the Food and Drug Administration, stem cell doctors generally perform same-day procedures similar to what Nitkowski received. That's not the case overseas.Going Outside The U.S. For TreatmentClinics in various countries in Europe, Australia and Asia offer stronger therapies. Patients can have stem cells taken out and then grown in a laboratory for weeks, producing millions more cells.Bradley believes those countries are 10 years ahead of the United States on stem cell therapy. He has referred some patients (not Steelers, following team policy) to a clinic in the Cayman Islands he considers safe.Athletes who go outside the U.S. for the therapy generally do so quietly. News reports said in 2011 that NFL quarterback Peyton Manning traveled to Germany for the therapy while recovering from neck surgery. Manning hasn't spoken publicly about the issue. Tennis star Rafael Nadal had stem cell treatment in 2014 to help his ailing back but hasn't endorsed the procedure.Pro teams in the United States can't stop players dealing with injuries from seeking as many opinions as they want. However, teams don't automatically endorse treatments."If the player does something we're not recommending, it's more or less on them," Steelers general manager Kevin Colbert said. "We firmly recommend that you stay here."The doctor who treated Nitkowski, Dr. Joseph Purita, gave stem cell therapy to pitcher Bartolo Colon in the Dominican Republic in 2010. Colon later tested positive for testosterone and was suspended 50 games. Purita denied giving Colon any performance-enhancing drugs but the circumstances only discouraged teams.In some ways, research on stem cells remains in the embryonic stages.Obi Wan Or Darth Vader?"There is so much hype, so much marketing," said Dr. Matthew Matava, president of the NFL's Physician Society. "The market kind of outpaces the research."Dr. Freddie Fu, head physician for University of Pittsburgh athletics, is even more suspicious. Fu has had stem cells in his lab for 15 years, but he won't use them on humans because of uncertainty, including unpredictability of what manipulated cells will do once introduced to a new area."You can have one cell be Obi Wan Kenobi, the other is Darth Vader," Fu said. "You're not sure which way it's going to go."Fu is all for progress. Yet for all of sports medicine's advances over the last 50 years, he believes there are some laws of nature we can't escape."If you get hurt, it's going to take time to heal," Fu said. "It's a part of life. There's always a way to think that maybe something is better, but it might not be."Benefits and risks of biotechnologyBy?Gale, Cengage Learning, adapted by Newsela staffBiotechnology is technology based on living systems and organisms. Specifically, it is the use of any biological process for agricultural, medical, industrial or environmental purposes. This includes everything from creating a new type of apple to developing a vaccine for a deadly disease. Biotechnology can also be used to clean up pollution while creating enough food and energy for the planet.The History Of BiotechnologyBiotechnology dates back to ancient times, when humans first learned to make beer with fermented grain. People adapted the natural fermentation process, where yeast converts sugars into carbon dioxide, to make bread. Early farmers also domesticated animals for farm work and as food. They chose animals with desirable characteristics and bred them to have offspring with those same qualities. This is called selective breeding. Farmers also used selective breeding to produce varieties of food that were tasty and easy to grow.?In 1919, Hungarian agricultural scientist Karoly Ereky invented the term "biotechnology." He used this term to describe how raw materials are turned into useful products through biological processes. In 1928, Scottish scientist Alexander Fleming used fermentation to produce penicillin. This is an antibiotic, or a medicine that fights harmful bacteria and infections. It has saved millions of lives and launched the modern pharmaceutical industry. Today, technologies can modify, or engineer, genes. Genetic engineering became possible after the discovery of the structure of deoxyribonucleic acid (DNA) in 1953.?Modern biotechnology led to the Green Revolution. Following World War II (1939–1945), scientists led by American biologist Norman Borlaug bred new varieties of corn and rice. These new crop varieties helped produce twice as much grain as traditional varieties. This was especially helpful for low-income countries with growing populations, such as Mexico, India and Pakistan. These countries were able to increase their food production quickly and avoid mass starvation. However, while the Green Revolution solved one problem, it created another. In establishing worldwide monoculture, which means growing only one crop over a wide area, it ultimately depleted the soil of nutrients and led to erosion and deforestation.?The Precautionary PrincipleSince the 1970s, agricultural scientists have pursued stem cell research, cloning and genetically modified, or GM, food. This biotechnology research has been strongly debated. Supporters of biotechnology believe it will result in breakthroughs that will allow people to live longer lives and solve environmental challenges. Opponents believe it could cause new problems that are worse than the ones it tries to solve.?Scientists and government officials have attempted to address these concerns through the precautionary principle. This is the idea that companies must prove a substance is safe before it becomes widely used. Several important United Nations sustainability treaties include the precautionary principle.Biotechnology And AgricultureMany scientists use biotechnology to discover new ways to efficiently and nutritiously feed people living in poverty. For example, some GM seeds are developed to grow in areas with little rainfall. This will help in arid, or dry, parts of the world. Other GM seed varieties are biofortified. That means they are designed to have more nutrients than traditional seeds. They can be grown in areas of the world where poor nutrition leads to high rates of infant mortality and disease.??Golden Rice is a GM rice grain that contains vitamin A. It can be grown in areas with poor nutrition. Photo: International Rice Research Institute/Wikimedia. [click to enlarge]However, these GMOs (genetically modified organisms) are controversial. Many people are concerned that they may not be safe to eat. Also, critics worry about the effects they could have on the environment and human health. Critics believe that just one or two varieties of GM seeds could become the primary source of food worldwide. That means people will be forced to buy their seeds from large corporations, becoming economically dependent. This also means that food security around the world would be at risk if a disease or pest affected those crops.?BioremediationBioremediation uses living organisms to remove pollution from the environment, and the organisms that do this are known as bioremediators. Composting is a type of bioremediation. This is when food and yard waste are collected and allowed to decompose, or break down, naturally. Bacteria break?down food or yard waste — like dead leaves — naturally until it becomes a substance that can be used as garden fertilizer. This type of recycling is a sustainable solution to making soil more fertile. Bioremediation can also be much more sophisticated. Scientists have developed bacteria that can digest toxic substances from nuclear waste sites or oil spills.?Biotechnology And BiofuelsBiotechnology is also used to create biofuels. These are fuels created from plants or algae. Biofuels are a less-polluting alternative to fossil fuels, which come from petroleum and coal found in the ground. Bioethanol, more commonly known simply as ethanol, is fuel made from corn, soybeans and other crops. Many vehicles can be adapted to run solely on bioethanol, but it is usually mixed with gasoline or diesel fuel.?Brazil is the world leader in using bioethanol as a fuel source. Over 80 percent of all vehicles in?Brazil?run on it.Depending on the way the crops are farmed, biofuels can be carbon neutral. This means that while the crops are growing, they absorb carbon dioxide from the environment. When they are burned, they release it back into the air. Overall, the level of carbon dioxide stays the same. Fossil fuels like oil and coal are never carbon neutral because, when burned, they release carbon into the atmosphere that has been trapped underground for millions of years.Issue Overview: VaccinesBy?, adapted by Newsela staffThe Centers for Disease Control (CDC) recommends that kids aged 6 and younger be given 9 vaccines. In all, 29 shots are recommended, as some of the vaccines must be given more than once. The idea behind vaccination is that the best way to provide protection against a disease is to give a person a small dose of that disease. This low-level exposure allows the body to build up resistance to the disease. So, to protect a person against smallpox disease, you vaccinate them with a tiny bit of smallpox. Protecting a person this way is known as immunization.There are no U.S. federal laws that say everyone must be vaccinated. However, all 50 U.S. states require certain vaccinations for children entering public schools. Most states offer medical and religious exemptions, though. A few also allow exemptions for people who believe vaccination is a bad idea.Supporters of vaccination say it is safe and that it is one of the greatest health developments of the 20th century. They point out that illnesses like rubella, diphtheria, smallpox, polio and whooping cough are now prevented by vaccination. As a result, they say, millions of children’s lives are saved. They claim it is extremely rare for people to react badly to vaccines.Opponents say that children’s immune systems can deal with most infections naturally. The immune system is the body's own set of defenses against disease. They argue that injecting questionable vaccine ingredients into a child may cause serious and even deadly side effects. They also claim that numerous studies prove that vaccines can trigger behavioral problems. In particular, they say vaccines may cause autism. Autism is a mental condition that makes it difficult to communicate with others.The Invention Of VaccinesThe first instance of vaccine promotion in the United States was in 1721. A minister named Cotton Mather encouraged vaccination in response to an outbreak of a disease called smallpox.?Vaccination as it is practiced today came into being when Edward Jenner, an English doctor, created the first smallpox vaccine in 1796. To make the vaccine, he used cowpox, a milder form of smallpox. Jenner’s innovation was used for 200 years, with updates. It eradicated smallpox. Eradication means the disease does not exist anywhere in the world. Some diseases are not eradicated, but are eliminated, which means that the disease is no longer present in a particular part of the world.In 1801, Benjamin Waterhouse, another physician, began using the "Cowpox Vaccine." This led Massachusetts to become the first U.S. state to promote the use of vaccination.In 1813, President James Madison signed into law An Act to Encourage Vaccination, which created the National Vaccine Agency. In 1855, Massachusetts passed the first U.S. state law requiring vaccinations for school children. By 1970, 29 states would require that children be immunized to attend public schools.Wakefield Accused Of Lying About Vaccines Causing AutismIn February 1998, Dr. Andrew Wakefield published an article about a study he had conducted. Wakefield claimed his study proved that the vaccine for measles, mumps and rubella can cause autism. Soon, some parents began using Wakefield’s article as a reason for not vaccinating their children.Brian Deer, an investigative reporter, looked into Wakefield's study. In a series of articles he accused Wakefield of "falsifying medical histories of children." Deer claimed Wakefield had purposely created fake evidence. He said Wakefield had been paid to do this by "lawyers hoping to sue vaccine manufacturers and to create a vaccine scare."?In 2011, the British Journal of Medicine published an article stating that Wakefield received over $674,000 from lawyers. Furthermore, it claimed that 5 of the 12 children examined by Wakefield had problems before being vaccinated and three never had autism. Britain stripped Wakefield of his medical license in 2011.Thimerosal Is A Controversial IngredientAnti-vaccine activists have been particularly concerned about a vaccine ingredient called thimerosal, which is added to vaccines to keep them from spoiling. In 1999, the American Academy of Pediatrics and the U.S. Public Health Service recommended that thimerosal be removed from vaccines.?In 2005, Robert F. Kennedy Jr. published an article titled "Deadly Immunity." In it, he claimed the CDC was covering up a "staggering number of earlier studies" that show a link between thimerosal and autism.?Kennedy's article led to an 18-month investigation by the U.S. Senate Committee on Health, Education, Labor and Pensions. The investigation concluded that Kennedy's claim was false. Thimerosal was being removed from childhood vaccines not because dangers had been proved, the report said, but only as a precaution. By 2009, thimerosal had been phased out of almost all vaccines in the U.S.Vaccines Deemed SafeIn August 2011, the Institute of Medicine issued a report on vaccines. The report stated that the evidence suggests that there is no link between the Measles-Mumps-Rubella (MMR) vaccine and autism. However, the report added that in some cases the chicken pox vaccine can cause pneumonia, meningitis or hepatitis. Such infections can occur in individuals with a weak resistance to disease, the report stated.?In 2012 the Cochrane Collaboration, a health research group, conducted its own independent investigation. It concluded that there was no “significant association" between the MMR vaccine and a number of conditions, including autism.Disappearing DiseasesMany of the diseases for which people receive vaccines have been eliminated or eradicated over time. Smallpox was declared eradicated in 1980, and was the first disease to be eradicated. Polio was declared eliminated in the United States in 1979 and in the Western Hemisphere in 1994. Rubella was declared eliminated in the Americas in 2015, and measles in 2016.?The World Health Organization states that the eradication and elimination of these diseases is due to successful vaccination programs. Those opposed to vaccination disagree. They say that cleaner living conditions and cleaner water are what led to the diseases' elimination, not vaccination.Sugar ribose may be found throughout the universeBy?Los Angeles Times, adapted by Newsela staffScientists believe that?sugar ribose, one of the building blocks of life, is likely on the?comets and asteroids zipping through the solar system. In fact, ribose may be more present across?the universe than was previously thought.Discovering ribose in space has?implications for the study of the origins of life on Earth.?It also might help us to understand?how much life there might be beyond our planet.Ribose is the “R” in RNA. RNA?stands for ribonucleic acid. It is a substance inside the cells of living things. It is one of the three macromolecules that are necessary for all life on Earth.?The other two are DNA, which RNA helps to transport, and proteins, which it helps to create.Scientists Look For AnswersMolecules are a group of atoms that represent the smallest unit that can take part in a chemical reaction. Scientists already knew that several of the molecules necessary for life are made from cometary ices interacting with?space radiation. Molecules made this way include amino acids, nucleobases and others. But ribose, which makes up the backbone of the RNA, was one molecule that?had been elusive. Not any more.The new work was just published?in Science. It fills in another piece of the puzzle of whether there might be life in outer space.Andrew Mattioda is?an astrochemist at NASA Ames Research Center who?was not involved with the study. He says that if?ribose can be found everywhere out in space, "the case gets a lot better that you’ll find life outside of Earth.”Many scientists believe that RNA is more ancient?than DNA. They believe that?before DNA came on the scene, an “RNA world” existed on Earth. However, ribose?only forms under specific conditions.?Scientists say those conditions were not present on our planet before life evolved. So, where did the ribose in the first RNA strands come from?Molecules Make It To EarthA?team of researchers wanted to find out if these molecules could have been delivered to Earth by asteroids and comets. They recreated the conditions of the early solar system in a lab. They wanted to answer the question of?whether ribose could easily be made in space.They started with water, methanol and ammonia. These molecules were abundant in the disk that formed around the sun at the dawn of the solar system, and are also abundant in gas clouds throughout the universe. They were put in a vacuum and then cooled to a cryogenic temperature of 80 degrees kelvin, or?minus 328 degrees Fahrenheit.The resulting ices were then heated to room temperature.?As a result,?the volatile molecules would pass from the solid to the vapor state by heating, and then condensing to solid form. This left the scientists a thin film of material that was a simulation of cometary ices.The experiment took about six days to complete in the lab. It?yielded just 100 micrograms of the artificial cometary ice residue.Sugar And Other CompoundsArtificial cometary ices have been created hundreds of times before in labs around the world.?It is only?now that researchers have the tools to detect sugars such as ribose in the samples they created.But it was not just sugar and sugar-related molecules that were?created in these experiments. Amino acids, carboxylic acids and alcohols were also created.“We are confronted with a very complex sample containing a huge diversity of molecules,” said Cornelia Meinert, a professor at?the University of Nice Sophia Antipolis, where the experiment took place. “The identification of individual compounds is therefore very difficult.”It wasn’t until the scientists?used a new method called multidimensional gas chromatography that they were able to sort out the molecules in the artificially created sample.?Meinert said that only then were they able to detect ribose.Abundant Throughout The Solar SystemThe researchers say that the ice samples like the ones they made in the lab could easily be made in other parts of the solar system.“Our ice simulation is a very general process that can occur in molecular clouds,” Meinert said. “It shows that the molecular building blocks of the potentially first genetic material are abundant in interstellar environments.”Scott Sandford is an astrochemist who has done similar work with cometary ices at NASA Ames Research Center. Sandford?said adding sugars to the list of molecules that can be forged in space is an important step. Now we can begin to understand?what building blocks of life may be available to foster life in other worlds.From pets to people? UC Davis vets' stem cell work gives humans hopeBy?The Sacramento Bee, adapted by Newsela staffDAVIS, Calif. — Morris has no teeth left. Every last tooth was pulled as a drastic cure for a painful condition that makes the 8-year-old cat’s mouth sore and inflamed. It is a terrible and exhausting illness that has baffled pet owners and veterinarians alike for decades.“We’re talking about a mouth that is inflamed with ulcers and looks like hamburger meat. It’s completely red and severely inflamed. It’s a very devastating disease in cats,” said Dr. Boaz Arzi,?a dental surgeon and researcher with the University of California, Davis (UCD) School of Veterinary Medicine.Arzi and several other?veterinarians?are currently testing a promising new treatment on Morris and about 20 other cats.The new treatment is a form of stem cell therapy.?Cats With Mouth Disease Get Stem CellsStem cells are "blank" cells that are capable of developing into other kinds of cells with specific functions.?They have proven useful in everything from healing wounds in dolphins to easing arthritis in pigs and horses. In general, stem cell treatments are tested on animals before being used on humans, to make sure they are both safe and effective.UC Davis' stem cell treatment appears as if it may have wider possibilities beyond being just a cure for cats. It holds tantalizing hope for humans afflicted with a similar and equally painful oral disease.For human patients such as Debbie Nicholau, 62, the stem cell therapies being tested on Morris and other cats could someday provide relief from a painful mouth disease. Three years ago?Nicholau?was diagnosed with oral lichen planus, which makes eating, and sometimes even speaking, difficult.“It’s like peppers on a raw wound — that’s what it feels like,”?Nicholau?said. She gets blood blisters inside her mouth and ulcers on her tongue and lips. “My mouth is just raw and on fire most of the time. It’s not pleasant.”Problem May Be In Body's Immune SystemThere is no cure or known cause for oral lichen planus. It often strikes middle-aged women and may be connected to a malfunctioning immune system. The immune system is the body's natural defense against disease, but when it becomes weakened it sometimes stops doing what it should be doing.Dr. Nasim?Fazel?is currently treating about 30 patients with?oral lichen planus,?including Nicholau.?In many cases, Fazel said, the disease is?difficult to treat and extremely painful.?Fazel is working closely with Arzi’s stem cell project to see if there is any potential for similar treatment in humans. “It’s so important,” Fazel said. “These patients, we don’t have a lot to offer them for treatment. Patients are suffering so badly — there’s a need for something that might work.”Morris the cat returned to UC Davis recently for a checkup following two stem cell infusions. He appeared completely uninterested in his role as a possible medical pioneer for humans.Cats Usually Nervous About TreatmentVeterinary worker Megan Badgley said Morris and the other cats are typically nervous when they are being seen, because for so many years they have lived in pain and endured numerous visits to veterinarians’ offices. “We go as slow as they need us to go. They tell us when they’re ready,” she said.For Morris, the irritated-mouth problems started appearing about three years ago, said the cat's owner,?Michael Altamirano. The caramel-colored tabby was not eating well, was clearly in pain and could not fully open his mouth to yawn. Altamirano took Morris to several vets, including one who extracted all of his teeth, the standard treatment for Morris' condition, which is known as feline chronic gingivostomatitis, or FCGS.“Leaving in his teeth wasn’t an option,” said Altamirano, who estimates he has spent nearly $3,000 on Morris’s disease care. Although Morris's symptoms improved after going toothless, he was not completely cured.Morris is exactly the kind of cat patient the UC Davis vet school was seeking for its clinical trial, now in its third year. Morris is one of 20 cats in the study that suffer from FCGS but have not responded to teeth extractions.Research Results Are PromisingSo far, stem cell therapy has shown promise as a cure. Stem cells are extracted from a cat's fatty stomach tissue, purified and grown in a UC Davis lab, then injected into a cat’s leg vein. Some cats get their own stem cells, while others receive those from healthy cats. Most get two infusions, 30 to 45 minutes long, a month apart.The treatment is intended to jump-start the cats’ immune system. Speaking in layman’s terms, “stem cells release chemicals or proteins that tell the immune system to behave properly,” said Arzi. “We convince the cells responsible for clearing inflammation to go back to doing what they’re supposed to be doing. Some are simply exhausted, so we revive them.”In most cases, the severe oral inflammations have calmed down, if not disappeared altogether, in afflicted cats.“The majority have shown clear or substantial clinical improvement,” said Arzi. “From a scientific viewpoint, they’re a normal cat.”Whether the treatment would work with humans remains to be seen, as humans could respond differently than dogs or cats.Still, for patients suffering from the disease, a clinical trial for humans cannot come soon enough.Nicholau said she would sign up “at the drop of a hat” in hopes of finding a cure. “This illness is so difficult to live with and to treat that people who have it are willing to do whatever we can to get relief. I’m willing to be a guinea pig.” ................
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