AIM:To accurately and realistically elucidate human stem cell behaviors in vivo and the fundamental mechanisms controlling human stem cell fates in vivo , which is urgently required in regenerative medicine and treatments for some human diseases, a surrogate human-rat chimera model was developed. METHODS:Human-rat chimeras were achieved by in utero transplanting low-density mononuclear cells from human umbilical cord blood into the fetal rats at 9-11 d of gestation, and subsequently, a variety of methods, including flow cytometry, PCR as well as immunohistochemical assay, were used to test the human donor contribution in the recipients.

No abstract

METHODS:Human hepatic parenchymal and stromal components and phenotypic changes of human cells during liver regeneration were examined by flow cytometry, in situ hybridization and immunohistochemistry.