干细胞研究及其伦理学问题

干细胞是动物体内一种独特的基本细胞类型。干细胞分化时，有些成为特殊类型的细胞，另一些仍维持干细胞，准备替代机体衰老和损伤的细胞。这些干细胞本身能够复制，以供机体终生组织更新的需要。最基本的多能干细胞存在于早期胚胎中，科学家们成功分离和培育干细胞的报告，为退行性疾病主损伤甚至致合性疾病的治疗带来了新的希望，然而，与此同时也引起了世界范围的关于使用人类胚胎和死亡胎儿进行研究的伦理大争论。

Ethical Issues in Human Stem Cell Research

The stem cell is a unique and essential cell type found in animals.When stem cells divide, some of the progeny mature into cells of a specific type , while others remain stem cells, ready to repair some of the everyday wear and tear undergone by our bodies. These stem cells are capable of continually reproducing themselves and serve to renew tissue throughout an individual's life. The most fundamental and extraordinary of the stem cells are found in the early-stage embryo. Scientific reports of the successful isolation and culture of the stem cells have offered hope of new cures for debilitating and even fatal illness, while at the same time renewing an important debate about the ethics of research involving human embryos and cadaveric fetal material.