Enrichment of Fetal Nucleated Red Blood Cells by Multi-core Magnetic Composite Particles for Non-invasive Prenatal Diagnosis

A novel kind of multi-core magnetic composite particles, the surfaces of which were respectively mo- dified with goat-anti-mouse IgG and antitransferrin receptor（anti-CD71）, was prepared. The fetal nucleated red blood cells（FNRBCs） in the peripheral blood of a gravida were rapidly and effectively enriched and separated by the mo- dified multi-core magnetic composite particles in an external magnetic field. The obtained FNRBCs were used for the identification of the fetal sex by means of fluorescence in situ hybridization（FISH） technique. The results demonstrate that the multi-core magnetic composite particles meet the requirements for the enrichment and speration of FNRBCs with a low concentration and the accuracy of detetion for the diagnosis of fetal sex reached to 95%. Moreover, the obtained FNRBCs were applied to the non-invasive diagnosis of Down syndrome and chromosome 3p21 was de- tected. The above facts indicate that the novel multi-core magnetic composite particles-based method is simple, relia- ble and cost-effective and has opened up vast vistas for the potential application in clinic non-invasive prenatal diag- nosis.

Isolation of Fetal Nucleated Red Blood Cells from Maternal Blood

To find a simple, effective method of isolating fetal cells from maternal peripheral blood for prenatal diagnosis, 45 women were studied with their gestation being 6-14 weeks and age 21- 30 years. The fetal cells were isolated from maternal blood by using discontinuous density gradient centrifugation. Some of the isolated cells were made smear and counted under the microscope; others were used for predicting fetal sex by PCR amplification of Y chromosome specific DYZ1 gene. The major cells in the upper separation interface were lymphocytes and monocytes, with occasionally seen nucleated red blood cells (NRBC); while those in the middle separation interface were neutrocytes, with NRBC scattering. The ratio of NRBC/nucleated cells was 1. 98±0. 28× 10-5. There was no significant difference between the first and second trimester (P>0. 05). The amount of isolated fetal cells was sufficient for prenatal genetic diagnosis. Male pregnancy was correctly predicted in 10 out of 13 cases. It is concluded that the method of discontinuous density gradient centrifugation was of considerable importance in the development of non-invasive prenatal genetic diagnosis.

Detection of Fetal Nucleated Erythrocytes and Fetal DNA from Peripheral Blood of Pregnant Women

In order to search for a more reliable method of sorting fetal nucleated red blood cells (NRBCs) and DNA from maternal peripheral blood and to identify origin of NRBCs and DNA, NRBCs were isolated from peripheral blood of 88 pregnant women by density gradient centrifugation and fluorescence activated cell sorter (FACS) respectively. Nested polymerase chain reaction was used to detect normal male SRY gene from blood plasma DNA of 65 pregnant women. The results revealed that fetal NRBCs were found in 14 of 27 maternal samples by density gradient centrifugation. The number of cells was from 1 to 10. Using FACS, CD71 + cells were identified among all 61 samples. The frequency was (0.35±0.25)×10 -2; The detectable rate of the SRY gene of blood plasma DNA from 46 women carrying male fetuses was 65.22 % (30/46). Non-detectable rate for 19 women carrying female fetuses was 94.74 % (18/19). It was concluded that the methods of sorting fetal NRBCs and DNA have already made great progress. The methods for fetal NRBCs and plasma DNA from maternal peripheral blood to diagnose genetic diseases seem to be the best methods of noninvasive prenatal diagnosis.

Protective Effect of Renshen Yangrong Decoction(人参养荣汤) on Bone Marrow against Radiation Injury in Mouse

Objective：To explore the effect of Renshen Yangrong Decoction（人参养荣汤,RYD） in protecting bone marrow from radiation injury.Methods：One hundred and eighty Kuming mice were subjected to the three tests for anti-radiation injury effect evaluation,i.e.the test of peripheral white blood cell（WBC） count, the test of bone marrow nucleated cell count,and the bone marrow micronucleus test,using 60 mice for each test.The mice in each test were divided into 6 groups：the blank control group,the model control group,the positive control group treated by Shiyiwei Shenqi Tablet（十一味参芪片,1.0 g/kg）,and three RYD groups treated with high（42.0 g/kg）,moderate（21.0 g/kg）,and low（10.5 g/kg） doses of crude drugs of RYD,with 10 mice in each group.The treatment was given by gastrogavage perfusion continuously for 7-14 days before mice received ^（60）Co-γray radiation and continued until the end of the experiment.The body weights of the mice were monitored,the changes in peripheral WBC and bone marrow nucleated cells were counted,and the variation in bone marrow micronucleated cells was observed on the respective appointed days.Results：A significant decrease in body weight,peripheral WBC count,and bone marrow nucleated cell count,as well as marked changes in bone marrow micronucleated cells were observed in the mice after radiation,indicating that the radiation injury model was successfully established.As compared with the model control group,the decrease in body weight,peripheral WBC count,and bone marrow nucleated cell count,as well as the increase in bone marrow micronucleus cell count in the high dosage RYD treated group were obviously inhibited or lessened （P0.05 or P0.01）.Conclusion：RYD showed obvious protective effect in mice with bone marrow injury induced by radiation.