The Star Online: Lifestyle: Health
The Star Online: Lifestyle: Health |
| Robodoc: UK surgeons find four-armed robot better than two steady hands Posted: 13 May 2014 09:00 AM PDT Robotic surgery has arrived! A four-armed operating robot named da Vinci is cutting into patients in ways that doctors and surgeons never thought they could. Under the glare of an operating theatre lamp, Paul Renforth at the Freeman hospital in Newcastle, England demonstrates the £2 million (RM11mil) da Vinci robot that has transformed surgery on patients. The four-armed robot is operated by a surgeon from a booth using two finger grips that move the arms and control the instruments on the end of each. All in, the robot is about 2m-high and 1.5m across. Its arms go inside the patient though small incisions in the skin. Looking through a 3D viewfinder hooked up to a camera on the robot, the surgeon can magnify, grasp, cut and cauterise tissue inside. The dexterity of the robot means surgeons can operate with more precision. They can remove cancerous tissue nearly impossible to reach otherwise. The robot is already used for heart bypass operations and to remove cancers throughout the body, including those in the lungs, throat, prostate, bladder, spleen and colon. "You can rotate the instruments 360 degrees, so they are more dexterous than the human hand," says Renforth, da Vinci co-ordinator at the hospital. "We are going into places now that we couldn't get into before. We treat laryngeal tumours at the back of the tongue, where we can (go) down and underneath and access and cut away the tumours. Normally, that would be done by splitting the lower jaw and going in from the side." At the end of each operation, the instruments on each arm are taken off, sterilised, and reused on the next patient. Most tools can be used up to 10 times before they're discarded. It's early days for robotic surgery, but at the Freeman, cancer operations seem to be more successful, because surgeons can see tumours better and remove tissue more easily. Surgeons learn to operate the robot by practising on cadavers. – Guardian News & Media |
| Posted: 13 May 2014 09:00 AM PDT Life-forms carrying synthesised DNA code could help churn out new drugs that couldn't be made otherwise. The first living organism to carry and pass down an expanded genetic code to future generations has been created by US scientists, paving the way for a host of new life forms whose cells carry synthetic DNA that looks nothing like the normal genetic code of natural organisms. Researchers say the work challenges the dogma that the molecules of life making up DNA are "special". Organisms that carry the beefed-up DNA code could be designed to churn out new forms of drugs that otherwise could not be made, they have claimed. "This has very important implications for our understanding of life," said Floyd Romesberg, whose team created the organism at the Scripps Research Institute in La Jolla, California. "For so long people have thought that DNA was the way it was because it had to be, that it was somehow the perfect molecule." From the moment life gained a foothold on Earth, the diversity of organisms has been written in a DNA code of four letters. The latest study moves life beyond G, T, C and A – the molecules or bases that pair up in the DNA helix – and introduces two new letters of life: X and Y. Romesberg started out with E. coli, a bug normally found in soil and carried by people. Into this he inserted a loop of genetic material that carried normal DNA and two synthetic DNA bases. Though known as X and Y for simplicity, the artificial DNA bases have much longer chemical names, which themselves abbreviate to d5SICS and dNaM. In living organisms, G, T, C and A come together to form two base pairs, G-C and T-A. The extra synthetic DNA forms a third base pair, X-Y, according to the study in Nature. These base pairs are used to make genes, which cells use as templates for making proteins. Romesberg found that when the modified bacteria divided, they passed on the natural DNA as expected. But they also replicated the synthetic code and passed that on to the next generation. That generation of bugs did the same. "What we have now, for the first time, is an organism that stably harbours a third base pair, and it is utterly different to the natural ones," Romesberg said. For now the synthetic DNA does not do anything in the cell. It just sits there. But Romesberg now wants to tweak the organism so that it can put the artificial DNA to good use. Cream of the crop "This is just a beautiful piece of work," said Martin Fussenegger, a synthetic biologist at ETH Zurich. "DNA replication is really the cream of the crop of evolution which operates the same way in all living systems. Seeing that this machinery works with synthetic base pairs is just fascinating." The possibilities for such organisms are still up for grabs. The synthetic DNA code could be used to build biological circuits in cells which do not interfere with the natural biological function; scientists could make cells which use the DNA to manufacture proteins not known to exist in nature. The development could lead to a vast range of protein-based drugs. The field of synthetic biology has been controversial in the past. Some observers have raised concerns that scientists could create artificial organisms which could then escape from laboratories and spark an environmental or health disaster. More than 10 years ago, the scientist Eckard Wimmer at Stony Brook University in New York recreated the polio virus from scratch to highlight the dangers. Romesberg said that organisms carrying his "unnatural" DNA code had a built-in safety mechanism. The modified bugs could only survive if they were fed the chemicals they needed to replicate the synthetic DNA. Experiments in the lab showed that without these chemicals, the bugs steadily lost the synthetic DNA as they could no longer make it. "There are a lot of people concerned about synthetic biology because it deals with life, and those concerns are completely justified," Romesberg said. "Society needs to understand what it is and make rational decisions about what it wants." Ross Thyer, at the University of Texas, in Austin, suggested the synthetic DNA could become an essential part of an organism's own DNA. "Human engineering would result in an organism which permanently contains an expanded genetic alphabet, something that, to our knowledge, no naturally occurring life form has accomplished. "What would such an organism do with an expanded genetic alphabet? We don't know. Could it lead to more sophisticated storage of biological information? More complicated or subtle regulatory networks? These are all questions we can look forward to exploring." – Guardian News & Media |
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