Vitiligo Definition and Overview. Vitiligo is an autoimmune skin disease in which there is a progressive destruction of the skinâs pigment-producing cells (melanocytes), resulting in areas of otherwise normal white skin devoid of melanin pigment. It is not unusual for hairs growing in areas of vitiligo to lose their normal color.
Sperm Cycle. Old sperm cells die off and new cells are created at a rate of about one percent each day. This means the entire sperm cycle requires approximately 100 days. The final 75 days represent a period of maturation for the sperm cell. This final step of sperm maturation, called spermiogenesis, puts the fuel into the tank and completes the development of the sperm cell (spermatozoon).
WHO (Edition 5) states that men with 4% normal sperm are considered to have normal sperm morphology. This is a topic that elicits much discussion among the experts, and is rather controversial. For Kruger Strict criteria, which is the method used by the Cryobank, sperm classified as borderline normal sperm are scored abnormal. Based on Kruger analysis men with 14% morphologically normal sperm are considered normal. The shape of the sperm is a reflection of proper sperm development (spermatogenesis) in the testicles. Men with defective spermatogenesis may produce a high percentage of abnormal sperm. There are many factors that can lead to formation of abnormal sperm.