Cytological characteristics of cord blood stem cells

为了确定脐带血细胞的特征，我们通过电子显微镜和CXCR3在CD4^+细胞和NK细胞上的表达检测了脐带血细胞的形态学特征。与正常外周血细胞相比，脐带血细胞常表现出不成熟的形态和独特的超微结构，如中性粒细胞中有核袋，单个嗜酸性粒细胞中有几个晶体，淋巴细胞中有畸形核。与骨髓细胞相比，脐带血细胞在细胞培养中产生大量未成熟的骨髓单核细胞谱系，并且表现出较弱的过氧化物酶反应。脐带血和外周血CD4^+细胞中CXCR3抗原的百分比分别为2.6%和30.8%，差异有统计学意义。然而，脐带血和外周血NL细胞无显著差异，提示脐带血干细胞移植的急性移植物抗宿主病较轻。

To identify the characteristics of cord blood cells, we examined their morphological features by electron microscopy and CXCR3 expression on CD4^+ cells and NK cells.Compared with normal peripheral blood cells, cord blood cells frequently showed immature morphology and a unique ultrastructure, such as nuclear pockets in neutrophilis, several crystaloids in a single eosinophilic granulocytes and deformed nuclei in lymphocytes. In contrast to bone marrow cells, cord blood cells yielded a large number of cells of immature myelo-monocytic lineages in cell culture, and demonstrated weaker peroxidase reaction.The percentage of CXCR3 antigen on cord blood and peripheral blood CD4^+ cells was 2.6% and 30.8%, respectively, demonstrating a significant difference. However, that on cord blood and peripheral blood NL cells was not significantly different suggesting milder acute graft-versus-host disease on cord blood stem cell transplantation.