As immune cells age, telomeres gets shorter and shorter when the cells divide. Ultimately, the cells change, can no divide and their ability to fight infections is compromised longer. This phenomenon is normally dubbed replicative senescence. For a solid immune system to function correction, a great deal of cell division must take place. For instance, whenever a virus invades the physical body, killer T-cells have receptors that recognize the invader and begin to create versions of themselves to combat the virus — – through division, they create increasingly more of an immune system ‘army’ to knock out the virus.In the 45-54 generation, the stroke rate is certainly 192 % for African-Americans weighed against 74 % for whites. That disparity in the incidence price evens out and changes as you monitor stroke in older Americans. In fact the racial distinctions reverse, so by the right time they reach about age group 80 and older, whites have a higher stroke rate compared with blacks, Howard said. It is not clear why the variations change with age, but it may need to do with different types of strokes occurring in various age groups. The end result is that specific subgroups are in greater risk and have to pay closer focus on their stroke-risk factors, said George Howard, Dr.PH., a UAB professor of biostatistics and a REGARDS co-principal investigator.