ABSTRACT
【Objective】 To analyze the causes of a case of hemolytic disease of the fetus and newborn (HDFN),and investigate the genetic background of maternal Rh deletion D--formation. 【Methods】 Blood samples of maternal and fetus were collected, and ABO blood typing, Rh blood typing, antibody screening and identification test were performed to explore the blood group serological characteristics of Rh deletion type D--, and Rh gene sequence was performed on parturient. 【Results】 The maternal blood group was identified to be O type, D--, and the anti-Hr0 antibody against Rh high-frequency antigen was suspected to be caused by multiple pregnancies which passes through the placental barrier and enable fetus to obtain anti Hr0 antibody, leading to HDFN, with genetic testing result as RH RHCE* Ce/RHCE* Ce. 【Conclusion】 In-depth research on the formation mechanism of Rh D-- in parturient should be conducted to provide clinical value for HDFN blood exchange treatment and blood transfusion in special blood group population.
ABSTRACT
BACKGROUND:The homing ability of mesenchymal stem cells is closely associated with the effects of celltransplantation. Clarifying the mechanism of chemotaxis and migration wil contribute to enhance the clinical application of mesenchymal stem cells. OBJECTIVE:To investigate the effect of Cdc42 in the homing of human umbilical cord mesenchymal stem cells. METHODS:First, mesenchymal stem cells were isolated from human umbilical cord, and co-cultured with tumor necrosis factorα, interleukin-1β, and transforming growth factorβ. Western blot assay was used to test the level of Cdc42. Besides, Cdc42 siRNA was synthesized by chemical method to transfect the cells, and cellmigration and adhesion were measured by Transwel and Matrigel separately. Meanwhile, the activity of signal molecule, extracellular regulated protein kinase 1/2, was evaluated by western blot. RESULTS AND CONCLUSION:The results indicated that the inflammation factors induced the highly expression of Cdc42 in human umbilical cord mesenchymal stem cells, almost double level to controls. siRNA notably inhibited the migration and adhesion of human umbilical cord mesenchymal stem cells through Cdc42 down-regulation, and the extracellular regulated protein kinase 1/2 and phosphorylation form were also decreased simultaneously. In a word, we speculate Cdc42 plays a role in the chemotaxis of human umbilical cord mesenchymal stem cells in vitro.