Repairing DNA damage in the human body
Researchers from the University of New South Wales have discovered that DNA repair is compromised at important regions of our genome, according to research published in Nature. Repairing damage in DNA from anything that causes a mutation, such as UV radiation and tobacco smoke, is a fundamental process that protects our cells from becoming cancerous. The UNSW scientists analysed more than 20 million DNA mutations from 1161 tumours across 14 cancer types. They found that in many cancer types, especially skin cancers, the number of mutations was particular high in regions of the genome known as “gene promoters”. Significantly, these DNA sequences control how genes are expressed which in turn determine cell type and function. The researchers showed that the numbers of DNA mutations are increased in gene promoters because the proteins that bind DNA to control gene expression block one of our cell repair systems responsible for fixing damaged DNA. This system is known as nucleotide excision repair and is one of a number of DNA repair mechanisms that occurs in human cells and the only one capable of repairing damage from UV light. “What this research also tells us is that while the human body is pretty good at repairing itself, there are certain parts of our genome that are poorly repaired when we sustain damage from mutagens such as UV light and cigarette smoke,” said Dr Jason Wong, lead author on the study. “By actively avoiding these harmful environmental factors, we can minimise the number of mutations occurring in our body that can lead to cancer.”
Progress towards transplantable pancreatic cells for diabetics
An international team led by researchers at the Salk Institute in the US and the Westmead Institute for Medical Research in Sydney has created insulin-making pancreatic cells in a petri dish, according to a report published in Cell Metabolism. When human stem cells develop into beta cells in a dish, they only reach a precursor stage, unable to fully mature; this prevents them from effectively producing insulin in response to glucose. Now, the scientists say they have discovered a protein that activates the maturation process in vitro, overcoming this longstanding obstacle in diabetes therapy development. They discovered that a nuclear receptor protein, estrogen-related receptor γ (ERRγ), occurred in much larger amounts in adult beta cells. When the researchers raised mice that lacked ERRγ, the animals’ beta cells couldn’t produce insulin in response to blood glucose spikes. But when the team instructed human beta-like cells grown in the lab to produce more ERRγ, those cells in culture began to respond to glucose and release insulin.
Paralysed man moves again after “nerve bypass”
Restoration of various finger, hand and wrist movement in a paralysed human has been achieved for the first time by using signals recorded from the patient’s motor cortex, reports a study published in Nature. Systems that translate neural activity into control signals for assistive devices such as robotic arms have previously been developed for human patients, and have also been applied to drive activation of paralysed muscles in non-human primates. However, no such approach had been shown to work in real-time to restore movement in humans until now. Researchers from the Feinstein Institute for Medical Research in the US implanted a microelectrode array in the motor cortex of a 24-year-old man with quadriplegia due to injury of the upper spinal cord. They used machine-learning algorithms to decode neuronal activity and control the activation of forearm muscles through a neuromuscular electrical stimulation system. The participant attended up to three sessions weekly for 15 months after implantation to use this electronic “neural bypass” system. The system enabled the participant to make isolated finger movements and six different wrist and hand motions, allowing him to grasp, manipulate and release objects. He was also able to use the system to complete functional tasks relevant to daily living, such as grasping a bottle, pouring its contents into a jar and using a stick to stir the contents of the jar.
E-cigarettes may pose passive smoking risk
E-cigarette vapour can contain harmful chemicals with known adverse health effects and may pose a passive smoking risk, particularly for vulnerable groups such as children and pregnant women, according to an Australian systematic review published in the journal Public Health Research & Practice. Researchers from Health Protection NSW reviewed the current evidence on passive exposure to e-cigarettes and found the majority of studies concluded e-cigarettes could pose a risk to bystanders. “The risk from passive exposure to e-cigarettes is likely to be less than conventional cigarettes but bystanders can be exposed to numerous pollutants above background levels and in concentrations that can be harmful to health,” said lead author, senior policy analyst Dr Isabel Hess. “E-cigarette vapour can contain elevated levels of nicotine, fine particulate matter, glycerine, propylene glycol, formaldehyde and metals. There is an urgent need for more research to determine the true extent of the risk from passive exposure to e-cigarettes,” Dr Hess said. “Based on the evidence available to date we can say that passive exposure to e-cigarettes has the potential to impact on people’s health.”
Combination of drugs for human parainfluenza virus
Griffith University’s Institute for Glycomics researchers have shown that two existing drugs readily available on the market can work together to more effectively treat the human parainfluenza virus. In research published in Nature journal Scientific Reports, Professor Mark von Itzstein, one of the co-discoverers of the world’s first anti-flu drug, zanamivir (Relenza), showed that when combined with suramin, an anti-parasitic drug used to treat human sleeping sickness, zanamivir had a much higher ability to block the infection. “This study offers a potentially exciting avenue for the treatment of parainfluenza infection by using a combining and repurposing approach of well established approved drugs,” Professor von Itzstein said. “Together they complement each other to inhibit parainfluenza growth and may mean it can be prescribed as a lower dosage of each for treatment.” He said his team discovered the potential of suramin to be used in parainfluenza treatment during screening tests of a wide range of approved drugs currently used to treat a variety of other diseases.
Rebuilding an oesophagus from stents and skin
US doctors report the first case of a human patient whose severely damaged oesophagus was reconstructed using commercially available Food and Drug Administration approved stents and skin tissue. Published in The Lancet, the authors said the reconstruction happened 7 years ago and that 4 years after the stents were removed, the patient continues to eat a normal diet and maintains his weight. The authors, reporting on the outcome of the procedure, say that research, including animal studies and clinical trials, are now needed to investigate whether the technique can be reproduced and used in other similar cases. To maintain the shape of the oesophagus and bridge the large defect, they used an endoscope to place self-expanding metal stents. The defect was then surgically covered with regenerative tissue matrix and sprayed with a platelet-rich plasma gel produced from the patient’s own blood to deliver high concentrations of growth factors that not only stimulate growth but also attract stem cells to stimulate healing and regeneration. One year after the stents were removed, endoscopic ultrasound images showed areas of fibrosis and regeneration of all five layers of the oesophageal wall. Full recovery of functioning was also established by swallowing tests showing that oesophageal muscles were able to propel water and liquid along the oesophagus into the stomach in both upright and 45° sitting positions.
Married cancer patients live a little longer
US researchers have found a link between being married and living longer among cancer patients. The study, published in Cancer, looked at 800 000 Californian adults diagnosed with invasive cancer from 2000 to 2009, and followed through 2012, and found the rate of death in men was 27% higher for those who weren’t married, while in unmarried women, the rate was 19% higher. The authors also found the differences varied when race was taken into account, with white people benefiting the most from being married, while Hispanics and Asian Pacific Islanders benefitted less. A team from the Cancer Prevention Institute of California and the University of California found that these patterns were minimally explained by greater economic resources among married patients, including having private health insurance and living in higher socioeconomic status neighborhoods. “Our study provides evidence for social support as a key driver,” the authors wrote. The findings indicate that physicians and other health professionals who treat unmarried cancer patients should ask if there is someone within their social network available to help them physically and emotionally.