字幕表 動画を再生する 英語字幕をプリント Dr. Frederick Banting and Charles Best are credited with discovering insulin that has saved the lives of millions of people who suffer from diabetes. Yet Best could have been a forgotten footnote in the medical history books if it weren't for a coin toss. It all goes back to 1921 when Banting, who was born in rural Ontario, Canada had returned from the war as a decorated veteran and embarked on a career in medicine. He had become deeply interested in diabetes - a disease that had plagued humanity for thousands of years and inevitably led to death. Diabetes results from too much sugar in the blood - which is why it's important for diabetics to limit junk food and carbs. In 1921, 14-year-old Leonard Thompson of Toronto was at death's door. He weighed just 65 pounds and was drifting in and out of consciousness in hospital. Little did he know that he would soon be in the history books. Scientists suspected diabetes was caused by a lack of insulin, a hormone formed in the pancreas that helps the body turn blood sugar into energy. But they couldn't prove their theory. While working as a physician and surgeon, Banting was also teaching part-time at the University of Western Ontario in London, two hours' drive from Toronto. While preparing a lecture on the pancreas, he had a eureka moment one night, rising from his bed at 2am to jot down a 25-word hypothesis on how to treat diabetes. He suspected that an enzyme formed in the pancreas broke down the insulin. So he set out to destroy the enzymes while preserving the cells that produced insulin. But first, he had to test his hypothesis on lab animals – in this case, dogs - by extracting insulin from healthy dogs and injecting it into dogs with diabetes, convinced that it would control if not cure the disease. So, he visited John James Rickard Macleod - a professor of physiology at the University of Toronto and an international expert in diabetes and asked if he could use his laboratory. Macleod was skeptical but agreed the idea was worth testing. He gave Banting lab space, 10 dogs, and insisted that he also have a research assistant because Banting didn't have any research experience himself. This is where the crucial coin toss came into play. Banting had a choice between two assistants: Charles Best and Clark Noble. Both recently completed their undergraduate degrees from the U of T's physiology and biochemistry program. Both knew full well that finding a cure for diabetes would make headlines around the world. Noble already had a distinguished research background. He had worked on important early studies helping to characterize the action of insulin and he co-authored many of the original papers describing insulin. For Best, the rush to help diabetics was personal. His aunt had died of the disease which had a profound effect on him. Banting needed only one assistant for what was supposed to be a two-month project. They decided to flip a coin to see who would join Banting for the first month and who would assist him for the second. Best won that coin toss. However, instead of switching assistants halfway, Banting was apparently so impressed with Best's work that he decided to keep the young protégé on for the entire project. Noble later wrote a letter explaining that “Best had become proficient in assisting Dr. Banting in his surgical techniques so it was mutually agreed, in the best interest of the experiments, that Best should continue to work out the full time with him.” Banting and Best began working in May 1921. Banting was 29 years old. Best was 22 and had not yet entered medical school. Banting was supposed to do the surgeries while Best was to measure blood and sugar levels but both actually became adept at the others' specialty. They recorded their experiments in a series of notebooks that documented their difficulties. Many of the dogs died of infections in the summer heat. But that didn't deter the two men. Their persistence paid off. At the end of July, they managed to reduce blood sugar levels in one diabetic dog. And then they tested it successfully on others. It hadn't yet been tried on humans but they were determined to save the life of 14-year-old Leonard Thompson whom I mentioned earlier so they prematurely injected him with impure pancreatic extracts from those dogs with the permission of the boy's father. Unfortunately, Thompson suffered a severe allergic reaction. Another researcher, the biochemist Dr. James Collip, was added to the team and managed to prepare a purer form of insulin that reduced the boy's blood sugar levels and saved his life. News of his recovery spread, leading families to write letters to the scientists asking for urgent treatment. Insulin clinics were established at various hospitals in the city. A University of Toronto surgeon who witnessed the early trials described how patients in comas injected with insulin “...awakened dramatically, snatched from death's door.” And in the case of this young girl, looked unrecognizable four months later. Banting, Best, and Collip sold the patent for insulin to the University of Toronto for just $1. They didn't want to profit from a discovery that could save lives and wanted everyone who needed insulin to be able to afford it. The University then entered into an agreement with an American pharmaceutical company to begin large-scale production. Within two years, insulin was widely available to diabetics around the world, saving the lives of millions of people. We'll never know whether the discovery of insulin would have taken a different path had Best lost that coin toss. Despite his role in one of the greatest discoveries of the 20th century, he didn't exactly get the credit. Best was left out when the Nobel prize for Physiology or Medicine in 1923 went to Banting and McLeod - the lab director who had spent the summer of 1921 vacationing in Scotland while his assistants worked away. The Nobel prize to Macleod was so surprising and controversial that Banting threatened to reject the award. He later reconsidered and gave Best half his prize money while Macleod gave his half to Collip – the researcher who purified insulin and saved the life of that 14-year-old boy who, by the way, lived another 13 years. He died of pneumonia at the age of 27, thought to be a complication of his diabetes. The original manufactured insulin came from pigs and cows and its impurities still resulted in complications over time, so people with diabetes still lived shortened lives. Since 1982, synthetic "human" insulin has been manufactured - artificially made from gene-splicing techniques. Its purity has increased to 99 per cent and today, insulin-dependent diabetics who take care of themselves by eating healthy food and exercising can enjoy a near-normal lifespan. Living a healthy lifestyle is more important than ever, especially as people work from home. I used to spend hours a day editing these videos sitting down, which was really hard on my back and negatively affected my posture. Which is why my new standing desk from UPLIFT has been a game-changer. This desk has been rated the best standing desk of 2021 by the product review website Wirecutter. The quality is incredible, there are loads of ways to customize it, and it comes with a 15-year warranty. If you're considering a standing desk, you can check out UPLIFT at the link in my description. For Newsthink, I'm Cindy Pom.
B2 中上級 米 How a Lucky Coin Toss Led to the Discovery of Insulin 19 1 joey joey に公開 2021 年 06 月 13 日 シェア シェア 保存 報告 動画の中の単語