Hope for chronic pain sufferers Swiss researchers have found a chemical compound that suppresses pain, apparently without the side effects of existing painkillers and without losing effectiveness. In University of Zurich tests on mice, the L-838,417 compound blocked pain without causing numbness or drowsiness. And, unlike morphine, it was effective throughout the nine-day trials, AFP reports. The spinal cord usually filters pain signals en route to the brain, but not in people suffering chronic pain - as many as one in five, according to the World Health Organisation. The compound will have to be refined before it can be tested on humans. Protein curbs hunger pangs Eating plenty of protein may be the best way to inhibit hunger. That's the finding of a small study by researchers at the University of Washington in Seattle that measured the effectiveness of different nutrients in suppressing ghrelin, a hormone secreted by the stomach that stimulates appetite. Although carbohydrates initially suppressed ghrelin strongly, the ghrelin levels soon rose even higher - in effect, eating carbohydrates leaves you even hungrier than before you ate. Fats suppressed ghrelin poorly, Reuters reports. 'Proteins were best in terms of the depth and duration of suppression,' says team leader David Cummings. Giant step towards skin cancer cure US researchers have successfully curbed the growth of melanoma, the deadliest form of skin cancer, in lab tests on mice by directing antibodies at the cells they identified as driving aggressive melanoma growth and resisting chemotherapy. The team from the Children's Hospital Boston and Brigham & Women's Hospital in Boston say the successful tests are 'a significant step' towards developing new therapies, WebMD reports. Flu virus survives on banknotes The flu virus can survive on banknotes for almost three weeks, say Swiss researchers, who now want to examine their role in transmitting the virus. The Geneva University Hospital researchers reportedly were surprised by the virus' resilience, particularly if mixed with mucus, AFP reports. They say such 'inert, non-biological support should not be overlooked in pandemic planning'. Saltwater alleviates kids' colds A dip in the briny may be just the ticket when it comes to children's winter colds, say researchers from the Czech Republic - or at least a saltwater nasal spray. Team leader Ivo Slapak says it's not clear why the spray eases cold symptoms faster, and slows the return of coughs and colds among children aged six to 10. It may be that the saltwater simply helps clear mucus, or trace elements in the water may play some role. The 12-week study by researchers at the Teaching Hospital of Brno involved 390 children, Reuters reports. Mobile calls a headache at bedtime Talking on a mobile phone before going to bed appears to cause insomnia, headaches and concentration difficulties, an 18-month US-Swedish study has found. The trials involved 71 men and women aged 18 to 45, some of whom were intermittently exposed to the equivalent of the radiation received when talking on a mobile, AFP reports. Those who were exposed 'reported headaches, it took longer for them to fall asleep and they did not sleep as well', says team leader Bengt Arnetz of Stockholm's Uppsala University.