Prevention of kidney stones may include a combination of lifestyle changes and medications. Lifestyle changes. You may reduce your risk of kidney stones if you: Drink water throughout the day. For people with a history of kidney stones, doctors usually recommend passing about 2.6 quarts (2.5 liters) of urine a day.
Melanin is the pigment that gives your skin its color, and it is produced in specialized skin cells called melanocytes. The darker your skin is, the more melanin these cells produce. They can be found deep in the epidermis, close to the basement membrane.
Until now, however, all attempts to grow these and some other adult stem cells, like blood stem cells, in culture have resulted in the cells differentiating into more specialized â but less therapeutically useful â progenitor cells.