Plant used in Chinese medicine fights chronic pain Researchers at the University of California, Irvine, may have found a new natural product that can relieve pain - dehydrocorybulbine, a compound found in the roots of the flowering plant Corydalis, a member of the poppy family. Reporting in the journal Current Biology , they say the extract dealt with all types of pain in animals - acute, inflammatory and chronic - and doesn't appear to lose effectiveness with time. Corydalis plants grow mainly in central eastern China, where underground tubers are ground and boiled in hot vinegar to treat pain. More testing for toxicity is needed before doctors should consider prescribing it to patients, say the scientists. Annual lung cancer screening urged High-risk adults between the ages of 55 and 80 should receive annual lung cancer screening with low-dose computed tomography, according to final recommendations from the US Preventive Services Task Force published in Annals of Internal Medicine . High-risk adults include heavy smokers or former heavy smokers who have quit within the past 15 years. In Hong Kong, about 90 per cent of male lung cancer patients are smokers, according to the Hospital Authority. Cholesterol link in Alzheimer's disease High levels of "good" cholesterol and low levels of "bad" cholesterol are linked with lower levels of the amyloid plaque deposition in the brain that is a hallmark of Alzheimer's disease, a new study published online in JAMA Neurology has found. A similar relationship is found between cholesterol and heart disease, say the researchers from the University of California, Davis. For HDL ("good") cholesterol, a level of 60 milligrams per decilitre or higher is best. For LDL ("bad") cholesterol, a level of 70 mg per decilitre or lower is recommended for people at very high risk of heart disease.