[Isolation and multipotent differentiation of human decidua basalis-derived mesenchymal stem cells].

OBJECTIVE: To investigate the biological features of human decidua basalis-derived mesenchymal stem cells (PDB-MSCs) in vitro and identify their capacity of multilineage differentiation. METHODS: PDB-MSCs were harvested from the decidua basalis of term placental by enzymatic digestion and density gradient centrifugation, and the growth characteristics and morphological changes of the MSCs were observed by inverted microscope. The proliferative ability of the cells was assessed by Cell Counting Kit-8. The cell cycle and expressions of the surface markers (CD29, CD44, CD73, CD90, CD34, CD45, and CD14) of the MSCs were identified by flow cytometry. Multilineage differentiation capacity of the cells was tested by inducing their differentiation toward osteoblasts, adipocytes and chondroblasts in vitro. RESULTS: MSCs isolated from human decidua basalis of term placental exhibited a morphology similar to that of bone marrow-derived MSCs, and grew into colonies in in vitro culture, where the cells proliferated rapidly after passage with a cell doubling time of 2.21∓0.21 days. More than 70% of the cells stayed in the resting stage (G(0)/G(1)) and showed positivity for CD29, CD44, CD73 and CD90, but not for CD14, CD34 or CD45. After induction, the cells showed positive results of alizarin red staining, oil red O staining and Alcian blue staining. CONCLUSION: Human decidua basalis contains a rich source of MSCs, which can be easily isolated and cultured without affecting their capacity of multilineage differentiation. The PDB-MSCs may have the potential as a novel source of stem cells.

[Construction of a mouse pDsRed2-N1-SDF-1alpha eukaryotic expression vector and its expression in mouse bone marrow mesenchymal stem cells].

OBJECTIVE: To construct the eukaryotic expression vector pDsRed2-N1-SDF-1alpha and observe its expression in the mouse bone marrow mesenchymal stem cells. METHOD: SDF-1alpha gene sequence with XhoI, EcoRI restriction enzyme cutting site was amplified from the total RNA of mouse smooth muscle cells by reverse transcription-polymerase chain reaction (RT-PCR) and inserted into the eukaryotic expression vector pDsRed2-N1 encoding red fluorescent protein gene, and the insertion was verified by endonuclease digestion and DNA sequencing. Mouse bone marrow mesenchymal stem cells identified with immunofluorescence assay for vimentin expression were transfected with the constructed plasmid pDsRed2-N1-SDF-1alpha, and the expression of sdf-1alpha was detected using immunofluorescence assay. RESULTS: The DNA fragment amplified by PCR from the total RNA was identical to SDF-1alpha from the gene library, and an identical DNA fragment was also amplified from the recombinants. Sequence analysis confirmed the successful insertion of SDF-1alpha into the pDsRed2-N1 vector and the eukaryotic expression vector pDsRed2-N1-SDF-1alpha was successfully constructed. The cultured mouse bone marrow mesenchymal stem cells positive for vimentin protein showed SDF-1alpha expression 24 h after transfection with the recombinant vector. CONCLUSION: The pDsRed2-N1-SDF-1alpha eukaryotic expression vector constructed is capable of expression of SDF-1alpha fusion protein in the mouse bone marrow mesenchymal stem cells.

[Genetic diversity of yam (Dioscorea opposita Thunb) detected by ISSR markers].

Genetic diversity of 28 cultivars of yam (Dioscorea opposita Thunb) was assessed by means of Inter-simple sequence repeat (ISSR) markers. The results showed that seven proper primers, with rich polymorphism, could be selected from a total of forty four ISSR ones; distinct differences appeared among 28 cultivars amplified bands, and the rate of polymorphic bands was 83.01%; Shannon's Information index was 0.3191; a Jaccard's genetic similarity matrix and a dendrogram for these cultivars were formed, in which they could be divided into four groups: Group 1 was composed of D. opposita. cv. Ribenbai, D. opposita. cv. Huashanyao and D. opposita. cv. Ribenyuan; Group2 contained D. opposita. cv. Xiaoye; Group 3 contained D. opposita. cv. No.1 Songye; other 23 cultivars were put into Group4. PCA(Principal component analysis) was employed to evaluate the resolving power of the markers to differentiate among them. This laid the foundation of the identification of yam cultivars and the efficient use of its germplasm resources.

[Development of an intelligent control system for radiography].

An intelligent control system has been designed using the single chip and the related circuit, and with the assemble language. It is connected with the common X-ray units to control the exposure dose. The result shows that three parameters for radiography are well controlled by the intelligent control system, and auto-radiography is realized.

[Determination of SARS-CoV by simplified nested fluorescent RT-PCR].

OBJECTIVE: To establish a simple rapid and sensitive nested RT-PCR method for detection of SARS coronavirus RNA by designing the specific primers for SARS and optimizing the parameters for PCR. METHODS: Primers and fluorescent probes were designed according to the sequences of SARS coronavirus genes available from GenBank. The optimization of the parameters for PCR was performed in PE 7700 thermal cycle. The 36 serum samples and 40 mouthwash of SARS patients and 80 samples of healthy people were tested. RESULTS: The positive rate of patient serum and mouthwash was 33.6%, (12/36) and 67.5%, (27/40), respectively, while the positive rate of healthy people was zero (0/160). CONCLUSION: The simple nested RT-PCR method was a rapid, efficient and sensitive one for SARS early diagnosis.

[Coxsackie virus B types were discriminated by RT-PCR].

OBJECTIVE: To develop a method for detection of coxsackie B virus type 1-6 by RT-PCR. METHODS: A pair of primers were designed to amplify all types of coxsackie B virus 1-6 efficiently. The PCR product was hybridized in micro-wells in which 6 type specific oligonucleotide probes had been coated respectively, colorimetric detection was performed to discriminate the types of coxsackie B virus. RESULTS: This method was shown to be concordant with the IgM ELISA, 71.7% of anti-coxsackie B positive cases could be detected by RT-PCR. CONCLUSION: The RT-PCR method can type coxsackie B virus efficiently and provides a tool for clinical diagnosis and epidemiological investigation.

[Assessment of genetic diversity of Rehmannia glutinosa germplasm detected by RAPDs and ISSRs].

RAPD and ISSR markers were used to assess the germplasm genetic diversity among 10 individuals of Rehmannia glutinosa, including 8 cultivars and 2 virus-free lines micropropagated by tip tissue culture. 17 RAPD primers and 10 ISSR primers, with polymorphic and informative patterns, were selected from a total of 80 RAPD ones and 44 ISSR ones to determine these individuals' genetic diversity. The 17RAPD primers and 10 ISSR primers generated 177RAPDfragments and 110 fragments, respectively. The number of effective loci, the percentage of polymorphic loci, Shannon's Information index (I) and effective number of alleles (Ne) is in turn109, 61.58%, 0.3135, 1.3641 for RAPD makers, and 79, 71.82 %, 0.3577 and 1.4037 for ISSR markers; Jaccard's genetic similarity matrice and dendrograms for the 10 individuals were formed based on RAPD and ISSR-generated polymorphic bands. In dendrograms, they could be divided into two groups: one group containing six individuals such as Zupei 85.5, Datian 85.5, jinzhuangyuan, Jinbai, Zupei 9302 and Datian9302; the other composed of 4 ones such as Beijing No.1, Dahongpao, Dihuang 9104 and wild dihuang; the correlation coefficient of 0.649 between RAPD and ISSR markers GSs indicated that these two markers were significantly correlated. The results revealed that RAPD and ISSR markers were suitable for assessment of germplasm genetic diversity of Rehmannia glutinosa, and ISSR marker was superior to RAPD marker.