Objective To find a safe and effective way for the collection of stem cells from peripheral blood in low body weight children. Methods Peripheral blood stem cells were collected altogether 15 times in 5 children with body weight lower than 20 kg. One day before the collection, a double cavity tube specially made for children was inserted into femoral vein and remained there for future use. Peripheral blood stem cells were separated by the separation vessel specially designed for children and collected in the collecting tank for children. After initialization, alien blood irradiated by X ray was infused in and moved through the separation machine to keep the blood balanced and hematocrit stable in the body of children. During the separation, anticoagulant/whole blood was kept between 1∶11 and 1∶13. The volume of blood processed every time was 2-4 times of total volume of child blood(2 700-5 850 ml). Results Mononuclear cells and CD34 + cells were successfully collected each time in all 5 children, enough for the transplantation of peripheral blood stem cells. Conclusion The way we developed to collect peripheral blood stem cells in children with low body weight is safe and effective.

Objective To study the influence of bone marrow microenvironment on leukemic cells during chemotherapy and the influence on leukemic cells' drug-resistance and anti-apoptosis. Methods Normal bone marrow stromal cells were isolated using Percoll, and then were cocultured with human acute lymphocyte leukemic cell line Jurkat cells in vitro. Apoptosis percentage of Jurkat cells labelled with Annexin V/PI were detected by FCM. Results Apoptosis percentage of Jurkat cells cocultured with bone marrow stromal cells for 24 hours was lower than those maintained in suspension (P

The determination of plasma factor Ⅷ related antigen (ⅧR:Ag) is a new method to estimate the function of blood coagulation introduced only recently. The concentration of this substance of 50 patients ill with chronic renal failure, neoplastic diseases, diabetes mellitus, (all these diseases were complicated with vascular changes) and 60 normal persons were determined.The data obtained showed that the concentration of plasma factor Ⅷ related antigen was significantly increased in all the 50 patients in comparing with the normal, and the increase was most marked in those patients with malignant diseases. The clinical significance of this phenomenon was discussed and it was suggested that the increase of this plasma factor Ⅷ related antigen might reflect the severity of the damage of the vascular endothelial cells in these patients.