Al Qaeda also maintains cells and personnel in a number of other countries to facilitate its activities.

Each of these observations is consistent with the notion that Notch activity maintains cells in a proliferative, unspecified state.

Some are hereditary, resulting from mutations in genes that create the enzymes needed for manufacturing fat or maintaining fat cells.

Niacin and niacinamide are required for the proper function of fats and sugars in the body and to maintain healthy cells.

Biononics maintain human cells at an optimum state; the body doesn't age biologically after you hit twenty-five.

But prosecutors say the group has maintained cells in Spain since at least the early 1990's, insinuating themselves among the country's growing Arab immigrant population.

Without buffers a researcher cannot maintain cells in tissue culture - they will quickly die!

This property maintains unspecialized and undifferentiated cells within the body.

Clearly the heart, vessels and lungs are all actively involved in maintaining healthy cells and organs, and all influence hemodynamics.

Oligodendrocyte progenitor transplants have been demonstrated to contribute to remyelination, but it is difficult to maintain such cells in reasonable concentrations at high puritiy.