Heart disease genes no death sentence

THE UNIVERSITY OF OTAGO

Share on print While genetic variants linked to heart disease can cause the disease to develop at a younger age, it doesn't appear to reduce an individual's life expectancy after a heart attack. Image: Dkart/iStockphoto Inheriting gene variants that increase the risk of developing coronary heart disease does not necessarily mean an individual is going to have reduced life expectancy if he or she suffers a heart attack. Two research papers revealing these findings by Dr Katrina Ellis and colleagues at the University of Otago, Christchurch have been highlighted in the leading international cardiology journal Circulation, along with 42 other papers from cardiac researchers around the world. “These results have attracted considerable international attention as we found for the first time that the most likely gene variants for risk of developing coronary heart disease didn’t have a major negative effect on survival after heart attack, as might have been expected by the medical and scientific community,” explains Dr Ellis. “When we examined the progress of patients with four key gene variants, who were admitted to Christchurch Hospital with either angina or heart attack, we found little or no effect on their subsequent survival eight to 15 years after a heart attack compared with those carrying the more common form of the gene sequence. “However we noted those who carried these gene variants tended to develop heart disease at a younger age or have more risk factors, like high cholesterol.” As the head of the research group Professor Vicky Cameron says: “This is good news for those patients, and of high interest to medical science as it would be expected that gene variants associated with a greater risk for having a heart attack would also indicate a negative rather than positive prognosis.” Research into gene variants and their relationship to heart attacks has rapidly progressed since 2007 when it became possible to examine all 23,000 genes in humans relatively quickly using new computerised technology. This lead to ‘genome-wide association studies’ which identify those gene variants most strongly linked to the development of coronary heart disease, and subsequent survival after treatment. Coronary heart disease is the leading cause of death world-wide and in New Zealand, with sixteen people dying each day from this condition. Risks include environmental or lifestyle factors such as smoking and obesity, but about 50% of heart disease is actually inherited through our genetic make-up and gene variants. “For many this means our genes make us more susceptible to lifestyle risk factors, such as bad diet or lack of exercise,” says Professor Cameron. Dr Ellis is now moving to the prestigious Mt Sinai School of Medicine in New York. However her research is continuing at the University of Otago, Christchurch under Professor Cameron. A new research project, ‘The Family Heart Study’, is looking at the specific genetic risk factors that contribute to early coronary heart disease in New Zealanders. This will enable identification of genetic factors, such as gene variants, which put people at risk of heart attack and will enable even earlier intervention and better chances of survival. Editor's Note: Original news release can be found here.

Neutrinos best studied in space

Neutrinos best studied in space

THE UNIVERSITY OF QUEENSLAND

Share on print Neutrinos are flowing through the Earth all the time, and many of them come from the Sun. In this computer simulation, the Sudbury Neutrino Observatory in Canada has detected a solar neutrino, which then produces a small burst of light, depicted by the colourful lines. The new research suggests the mass of neutrinos is better measured in the galaxy than in experiments such as this one. Image: Lawrence Berkeley National Laboratory The lightest known subatomic particles in the Universe are now able to be more accurately scrutinised, in light of new astronomic research two years in the making. After more than 200 nights of galaxy-gazing and thousands of calculations, an international team of astronomers, including researchers from The University of Queensland, has published a new study that has made a remarkable headway in the way the mass of neutrinos are measured. The study, published in the May edition of Physical Review D Rapid Communication concludes that cosmological galaxy measurements are more effective than laboratory experiments on Earth when it comes to constraining neutrino mass for measurement. Neutrinos are the subatomic-sized fundamental particles floating in the Universe and the lightest massive known particles, yet they are traditionally treated as not having any mass. Lead author of the study, Dr Signe Riemer-Sørensen of the UQ School of Mathematics and Physics, said this new study would allow researchers to gain a more accurate and highly sensitive picture of neutrino mass, and this could ultimately lead to new understandings of the Universe. “This research paves the way for more sensitive future galaxy surveys to understand the mysterious workings of the Universe, and will help in new advancements such as improved models of supernova explosions and in designing neutrino telescopes that can probe much more distant objects than classical telescopes,” said Dr Riemer-Sørensen. Although laboratory experiments on Earth so far have been able to measure the differences in the masses between the various species of neutrinos, they have been unsuccessful in measuring the absolute neutrino mass with sufficient sensitivity. Using the Universe as a large particle physics experiment, the team in this study attempted to limit the range of possible neutrino masses by understanding how galaxies form. “One of the major challenges is that galaxy formation is not well-described theoretically,” said Dr Riemer-Sørensen. “We have tested a range of previously used theories and demonstrated that most of them are not precise enough to use with present and upcoming galaxy surveys with the much-desired higher level of sensitivity to the neutrino mass.” Using high-quality data from the team's WiggleZ Dark Energy Survey - a massive three-dimensional galaxy map of 240,000 galaxies - the researchers in this study applied a mixture of analytical modelling and simulation to achieve their results. “Despite the modelling challenges, cosmology does a much better job than laboratory experiments when it comes to constraining the neutrino mass,” said Dr Riemer-Sørensen. The team is currently working on refining the neutrino mass measurement by combining their results with other independent data sets, such as measurements from other astronomical observations. Other researchers in the study are Professor Michael Drinkwater, Dr Tamara Davis and Dr David Parkinson, all from the UQ School of Mathematics and Physics, as well as researchers from Australia, USA, South Africa, and Canada. Editor's Note: Original news release can be found here.

Stories of Unbelievable Dog Friendship