Science news digest – 11th February 2013
In the science news this week, a virus that has tripled the liver cancer survival time, NASA’s Curiosity rover starts to drill, measles rates reach 18-year high, and finally… the world’s largest captive crocodile dies in the Philippines.
Liver cancer survival time tripled by virus
The virus, vaccinia, which was used in the vaccine against smallpox has now shown to be effective in improving the survival time for people with a severe form of liver cancer, reported New Scientist.
Thirty people with hepatocellular carcinoma were given three doses of the virus, which had been genetically engineered, directly into their liver tumour over the course of a month.
Half the volunteers received a low dose of the virus, the other half a high dose. Subsequently, the members of the low and high-dose groups survived on average 6.7 and 14.1 months respectively.
In comparison, sorafenib – the best existing medication for that form of cancer – prolonged life by just three months according to trials run several years ago.
Two of the patients in the high dose group were still alive more than two years after the treatment. "It's a very substantial survival benefit," says Laurent Fischer, president of Jennerex, the company in San Francisco developing the treatment under the trade name Pexa-Vec.
Not only did the virus shrink the primary tumour where it was first administered, it was also able to spread to and shrink any secondary tumours outside of the liver. "Some tumours disappeared completely, and most showed partial destruction on MRI scans," says David Kirn, head of the study at Jennerex. The destruction was equally as bad in both the primary and secondary tumours.
"This clinical trial is an exciting step forward to help find a new way of treating cancers," says Alan Melcher of the University of Leeds, UK, who was not involved in the study. "It helps demonstrate the cancer-fighting potential of viruses, which have relatively few side effects compared with traditional chemo or radiotherapy," he says. "If it proves effective in larger trials, it could be available to patients within five years."
Curiosity starts to drill
NASA’s Mars rover, Curiosity, has drilled into the surface of Mars for the first time, reported BBC news.
The drill has also collected a powdered sample of Martian rock for analysis, which will be sieved and inspected before being delivered to the robot’s onboard laboratories.
This will be the first time that the interior of a rock on another planet will be investigated in this way, making it a significant achievement for the US space agency.
Curiosity will be looking to see whether in the past that area of the Gale Crater on Mars ever supported life, and finding out the constituent parts of the rocks should provide some telling evidence.
The rover started by hammering down on a rock in order to test the equipment, but it then drilled a shallow hole, roughly 2cm deep, producing a fine powder for the robot to pick up.
The rover was then instructed to drill deeper, which pushed some of the cuttings into the tool’s sample acquisition chamber.
Some of this powder will be used to scrub the machinery’s innards in order to remove any contamination that may have travelled on the rover from Earth.
The rest will be sorted to a size and volume that can be put into the Chemin and Sam labs on the rover. They will determine the rock’s precise chemistry and mineralogy, and any interesting carbon chemistry that may be there.
Measles cases reach 18 year high in England and Wales
There were 2,016 confirmed cases of measles in England and Wales in 2012 the Health Protection Agency (HPA) announced last week. This is the highest annual total of the highly infectious disease since 1994, reported the Guardian.
According to the HPA, the majority of the cases occurred in Merseyside, Surrey and Sussex. People are protected against the potentially lethal diseases measles, mumps and rubella with the MMR vaccine.
Dr Mary Ramsay, head of immunisation at the HPA, said: "Coverage of MMR is now at historically high levels but measles is highly infectious and can spread easily among communities that are poorly vaccinated, and can affect anyone who is susceptible, including toddlers in whom vaccination has been delayed.
"Older children who were not vaccinated at the routine age, who may now be teenagers, are at particular risk of becoming exposed, while at school for example.
"Measles continues to circulate in several European countries that are popular with holidaymakers. Measles is a highly infectious disease, so the only way to prevent outbreaks is to make sure the UK has good uptake of the MMR vaccine, and that when cases are reported, immediate public health action is taken to target unvaccinated individuals in the vicinity as soon as possible.
"Measles is often associated with being a disease of the past and, as a result, people may be unaware that it is a dangerous infection that can lead to death in severe cases. Parents should ensure their children are fully protected against measles, mumps and rubella with two doses of the MMR vaccine.
"Parents of unvaccinated children, as well as older teenagers and adults who may have missed MMR vaccination, should make an appointment with their GP to get vaccinated. If you are unsure if you or your child has had two doses of the vaccine, speak to their GP, who will have a record."
World’s largest captive crocodile dies
The largest saltwater crocodile in captivity has died in the Philippines, reported the BBC news website. The reptile, called Lolong, was 6.4m (21ft) long and weighed a whopping 1,075kg (2,370lb).
Lolong was captured in the town of Bunawan in September 2011 after a three-week hunt involving dozens of people. The crocodile had been blamed for the death of at least one person, and was declared the world’s largest captive crocodile by Guinness World Records last year.
The Bunawan mayor, Edwin Elorde, said that Lolong had not been well for about a month, and had not been eating, although a full investigation will be carried out by wildlife experts to determine the exact cause of death.