Tomas Lindahl - Francis Crick Institute and Clare Hall Laboratory, Hertfordshire, UK

Tomas Lindahl

Paul ModrichHoward Hughes Medical Institute and Duke University School of Medicine, Durham, NC, USA
Paul Modrich
Aziz Sancar - University of North Carolina, Chapel Hill, NC, USA

“for mechanistic studies of DNA repair"

The cells’ toolbox for DNA repair

The Nobel Prize in Chemistry 2015 is awarded to Tomas Lindahl, Paul Modrich and Aziz Sancar for having mapped, at a molecular level, how cells repair damaged DNA and safeguard the genetic information. Their work has provided fundamental knowledge of how a living cell functions and is, for instance, used for the development of new cancer treatments.
Each day our DNA is damaged by UV radiation, free radicals and other carcinogenic substances, but even without such external attacks, a DNA molecule is inherently unstable. Thousands of spontaneous changes to a cell’s genome occur on a daily basis. Furthermore, defects can also arise when DNA is copied during cell division, a process that occurs several million times every day in the human body.

The reason our genetic material does not disintegrate into complete chemical chaos is that a host of molecular systems continuously monitor and repair DNA. The Nobel Prize in Chemistry 2015 awards three pioneering scientists who have mapped how several of these repair systems function at a detailed molecular level.

In the early 1970s, scientists believed that DNA was an extremely stable molecule, but Tomas Lindahl demonstrated that DNA decays at a rate that ought to have made the development of life on Earth impossible. This insight led him to discover a molecular machinery, base excision repair, which constantly counteracts the collapse of our DNA.

Aziz Sancar has mapped nucleotide excision repair, the mechanism that cells use to repair UV damage to DNA. People born with defects in this repair system will develop skin cancer if they are exposed to sunlight. The cell also utilises nucleotide excision repair to correct defects caused by mutagenic substances, among other things.

Paul Modrich has demonstrated how the cell corrects errors that occur when DNA is replicated during cell division. This mechanism, mismatch repair, reduces the error frequency during DNA replication by about a thousandfold. Congenital defects in mismatch repair are known, for example, to cause a hereditary variant of colon cancer.

The Nobel Laureates in Chemistry 2015 have provided fundamental insights into how cells function, knowledge that can be used, for instance, in the development of new cancer treatments.

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Penicillin changed everything. Infections that had previously killed were suddenly quickly curable. Yet as Maryn McKenna shares in this sobering talk, we've squandered the advantages afforded us by that and later antibiotics. Drug-resistant bacteria mean we're entering a post-antibiotic world — and it won't be pretty. There are, however, things we can do ... if we start right now.

In mid-march, a village called Sarmin, in Northwestern Syria was attacked by bombers from a helicopter. There is no explosion, no fire but it was the most worst form of attack where the civilians did not injured by physical wounds. But their struggle started after a few minutes who rushed to the nearest hospitals as they suffered from various ailments such as severe coughing, burning sensation in eyes and throat and most of them were unable to breathe. 

“There was a very strong chlorine smell there,” Muhammad Yazan, a local activist, told Human Rights Watch. Yazan went to the impact site in Sarmin, as well as to another village that was attacked in Idlib province. “One of our team members passed out due to the smell. It was horrible. My eyes were burning. I wanted to throw up. My skin felt like I had rashes.”

Photo: Bryce Vickmark
Dr. Sangeeta Bhatia     
20th Heinz Award for Technology,the Economy and Employment

Dr. Sangeeta Bhatia, bioengineer at the Massachusetts Institute of Technology, is recognized for her seminal work in tissue engineering and disease detection, including the cultivation of functional liver cells outside the human body.

As a graduate student at MIT, Dr. Bhatia was assigned the task of cultivating living liver cells in a petri dish, an endeavor that had been attempted for many years. A visit to a microfabrication facility — where students laid circuits out on silicon chips — inspired her to see if the same technology could be used to “print” tiny liver cells on plastic. The result was the first “microliver,” a miniature model organ now widely used to test drug reactions efficiently and predictively.

Dr. Bhatia’s team has also made singular strides in developing simple, affordable cancer screening tools. One uses tiny particles or nanoparticles to create biomarkers for cancer in urine samples on paper strips; the other is a “cancer-detecting yogurt,” containing engineered probiotic bacteria.

The United States went to war in Iraq expecting to destroy an active weapons of mass destruction program. Instead, it found only remnants of chemical arms built in close collaboration with the West.

Manu Prakash - An Assistant Professor of bio engineering at Stanford University, who made a fold-able microscope which he is calling it as "Foldscope". In the words of this IIT Kanpur student, the world need it and every coming generation child should carry a pocket microscope and those children should know what actually they are dealing with "microscopically".

Royal Society of Chemistry conducting a "Chemistry World Science Communication Competition-2014" and the topic is Chemistry and Art. The participants should write an article using around 800 words and the selected topics will be published in Chemistry World.

Forget stitches — there's a better way to close wounds. In this talk, TED Fellow Joe Landolina talks about his invention — a medical gel that can instantly stop traumatic bleeding without the need to apply pressure.

What do the latest studies into our sexual orientation reveal?

Are there dangers in framing sexuality through the lens of genetics? On the podcast this week we talk to Dr Alan R Sanders, a psychiatrist at North Shore University Health System Research Institute in Chicago who has been carrying out large scale research with 400 pairs of homosexual brothers to look for the genetic contribution to sexual orientation in men.

"Antibiotic drugs save lives. But we simply use them too much — and often for non-lifesaving purposes, like treating the flu and even raising cheaper chickens. The result, says researcher Ramanan Laxminarayan, is that the drugs will stop working for everyone, as the bacteria they target grow more and more resistant. He calls on all of us (patients and doctors alike) to think of antibiotics — and their ongoing effectiveness — as a finite resource, and to think twice before we tap into it. It’s a sobering look at how global medical trends can strike home."

The first patient to ever be treated with an antibiotic was a policeman in Oxford. On his day off from work,he was scratched by a rose thorn while working in the garden. That small scratch became infected. Over the next few days, his head was swollen with abscesses, and in fact his eye was so infected that they had to take it out, and by February of 1941, this poor man was on the verge of dying. He was at Radcliffe Infirmary in Oxford, and fortunately for him, a small team of doctors led by a Dr. Howard Florey had managed to synthesize a very small amount of penicillin, a drug that had been discovered 12 years before by Alexander Fleming but had never actually been used to treat a human, and indeed no one even knew if the drug would work, if it was full of impurities that would kill the patient, but Florey and his team figured if they had to use it, they might as well use it on someone who was going to die anyway.

Read the full interactive script here.....