Washington, Apr 20 : Exposure to marijuana or hashish during adolescence has a lasting impact on cognitive processes such as learning and memory, says a new study.

Lead researcher Dr. Peter Winsauer, from Louisiana State University suggests that illicit use of THC, an ingredient of marijuana or hashish, during adolescence produces persistent changes in the brain that sensitise females to the negative effects of THC later in life.

Washington, Apr 20 : Genetic variations in the micro-RNA (miRNA) processing pathway genes and miRNA binding sites could predict a woman''s risk of developing ovarian cancer and her prospects for survival, according to a new study.

The study by researchers from The University of Texas M. D. Anderson Cancer Centre was the first to examine the association of genetic variants related to miRNA with ovarian cancer risk, overall survival for ovarian cancer patients, and platinum-based chemotherapy response.

London, Apr 20 : In what is being called as a "big step" towards answering one of medical science''s great questions, Scottish scientists have discovered genetic "brakes" which could slow down or stop diseases such as multiple sclerosis and cancer.

The findings by the researchers at the Roslin Institute could lead to new treatments and even cures for illnesses, which affect the immune system.

London, Apr 20 : Cancer is not just down to genes, unhealthy diet and poor lifestyle also contribute to the potentially fatal disease, say experts.

Dr Rachel Thompson, science programme manager for the World Cancer Research Fund (WCRF) dispelled the myth insisting lack of exercise and being overweight - causes three times as many cases of cancer as genetics.

According to her, 39 per cent of the most common cancers, including breast and bowel, could be prevented through a good diet, exercising and keeping weight under control.

Washington, Apr 20 : Incorporating an omega three fatty acid- found in fish oil- in the diet could help prevent diseases like Parkinson''s and Huntington''s.

Dr. Nicolas Bazan, form the Louisiana State University Health Sciences Center, showed that the omega three fatty acid, docosahexaenoic acid (DHA), prevented the misfolding of a protein resulting from a gene mutation in neurodegenerative diseases.

For the study, researchers developed a cell model with a mutation of the Ataxin-1 gene.

Washington, Apr 20 : A simple urine test could predict if a smoker is at the risk of developing lung cancer or not, according to a new study.

Lung cancer afflicts some smokers and not others, and now University of Minnesota researchers have hypothesised that the presence of the metabolite NNAL in a patient''s urine might predict risk of lung cancer.