ABSTRACT
BACKGROUND: Long-term complications of cesarean section include placenta praevia, placenta accreta, cesarean scar pregnancy and uterine rupture. These life-threatening complications in pregnant women maybe result from the defects of endometrium and uterine smooth muscle as well as poorly formed decidua in the scar of cesarean section. Mesenchymal stem cells have the function of repairing tissue injuries, and the amount of cells homing to the site of injury may affect the effect of tissue repair. OBJECTIVE: To explore the distribution and homing of bone marrow mesenchymal stem cells from male rats into rat models of cesarean section. METHODS: Bone marrow mesenchymal stem cells isolated from male rats in vitro were cultured and identified. Female Wistar rats were randomized into two groups: cesarean section group and control group. Rats in the cesarean section group were given intravenous administration of bone marrow mesenchymal stem cells from male rats via the tail vein on day 21 after cesarean section, and non-operative rats in the control groups were given the same amount of bone marrow mesenchymal stem cells from male rats after natural delivery. Rats in the two groups were sacrificed on days 7 and 28 after cell injection. The distribution of bone marrow mesenchymal stem cells from male rats in tissues (including heart, lungs, livers, kidneys, and uterine scar) was detected by measurement of the SRY mRNA level using SPY-PCR. RESULTS AND CONCLUSION: In the cesarean section group, the SRY gene was most abundant in the lung, followed by the liver and the kidney on day 7 after injection, although the distribution of SRY gene in the heart and uterine scar was low; on day 28 after injection, the levels of SRY gene in the lung, liver and kidney decreased (P < 0.05), but had no significant changes in the heart and uterine scar (P > 0.05). In the control group, the distribution of SRY gene was similar to that in the cesarean section group on both days 7 and 28 after injection, and the levels of SRY gene in the heart and uterus were low. These findings reveal that allogeneic bone marrow mesenchymal stem cells implanted mainly distribute in tissues with abundant blood flow, including lungs, livers and kidneys. And the cell number decreases gradually over time. Since the amount of implanted cells in the heart and uterus is very low, the change with time is not obvious. Cesarean section injury has no impact on the distribution of bone marrow mesenchymal stem cells in pregnant rats and there is of course no increase in the homing and colonization of bone marrow mesenchymal stem cells in a cesarean scar.
ABSTRACT
<p><b>OBJECTIVE</b>To analyze the distribution of the human leukocyte antigen (HLA)-A, B and DRB1 allele and haplotype in cord blood samples preserved in Guangzhou Cord Blood Bank collected in the last 10 years.</p><p><b>METHODS</b>The HLA-A, B and DRB1 genotyping of 4194 cord blood samples were detected by Special Monoclonal Tray, PCR-sequence specific promer (PCR-SSP), PCR-sequence specific oligonucleotide probe (PCR-SSO) and sequence based typing (SBT). Frequencies of HLA-A, B and DRB1 allele and haplotype were calculated by Arlequin software.</p><p><b>RESULTS</b>The total numbers of HLA-A, B and DRB1 alleles are 18, 43, 13 respectively. The obviously high frequency alleles are A*11, A*02, A*24, A*33, B*40, B*15, B*46, B*13, DRB1*12, DRB1*15, DRB1*09 and DRB1*04, with accumulative frequency of each locus being more than 50%. The most common haplotypes are A2-B46, B46-DR9, A11-DR12 and A2-B46-DR9.</p><p><b>CONCLUSION</b>The distribution of HLA-A, B and DRB1 allele and haplotype of cord blood in Guangzhou Cord Blood Bank has typical characteristics of southern Chinese Han population. Authors' data may help in searching for appropriate donors.</p>