Expression of nestin and neurogenin 3 in the human fetal pancreas / 中华外科杂志

<p><b>OBJECTIVE</b>To examine the expression of nestin and neurogenin 3 (Ngn3), the markers of pancreatic stem cells, in the human fetal pancreas.</p><p><b>METHODS</b>The human fetal pancreas tissue of 12 and 14 weeks were examined for the expression of nestin and Ngn3 using the techniques of immunofluorescence dye and RT-PCR.</p><p><b>RESULTS</b>Both nestin and Ngn3 expressed widely in 12 and 14 weeks before in human fetal pancreatic tissue. In these positive cells there was no co-expressing insulin or glucagon. There were nestin and Ngn3 co-expressing cells in ducts but not in the islets. The results of RT-PCR also indicated the expression of nestin and Ngn3.</p><p><b>CONCLUSIONS</b>There was no expression of the markers of mature endocrine cells in the nestin and Ngn3 positive cells, and they were the marks of no-differentiation cells in the human fetal pancreatic tissue.</p>

Flow cytometry analysis and differentiation study of selected nestin positive cells / 中国医学科学院学报

<p><b>OBJECTIVE</b>To verify the hypothesis that selected nestin positive cells derived from human fetal pancreas (according as medical ethnics) have surface markers similar to bone marrow mesenchymal stem cells (MSCs), and that these cells have multilineage potential.</p><p><b>METHOD</b>The cell surface markers were determined by flow cytometry, and then the potential that these cells might be differentiated into adipocytes and osteoplasts were explored.</p><p><b>RESULT</b>These cells have similar surface markers as MSCs of bone marrow origin. These cells was induced to differentiate into adipocytes and osteoplasts.</p><p><b>CONCLUSION</b>Selected nestin positive cells derived from human fetal pancreas have certain characteristics of MSCs.</p>

Mutation analysis of PAX6 gene in a large Chinese family with aniridia / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Mutations in PAX6 gene have been shown to be the genetic cause of aniridia, which is a severe panocular eye disease characterised by iris hypoplasia. However, there is no study to do genetic analysis of aniridia, although there are several case reports in China. Here, we describe a mutation analysis of PAX6 in a large Chinese family with aniridia.</p><p><b>METHODS</b>Genomic DNA from venous blood samples was prepared. Haplotype analysis was performed with two genetic markers (D11S904 and D11S935). Fourteen exons of the PAX6 gene were amplified from genomic DNA. Polymerase chain reaction (PCR) products of each exon were analysed by single strand conformational polymorphism (SSCP). The PCR products having an abnormal pattern were sequenced to confirm the mutation.</p><p><b>RESULTS</b>Significant evidence for allele sharing in affected patients was detected suggesting that PAX6 mutation links to aniridia in this family. An extra band corresponding to exon 9 in PAX6 was found by single strand conformational polymorphism analysis in all the aniridia patients in this family, but not detected in the unaffected members. A mutation of C to T was detected by sequencing at the nucleotide 1080 that converts the Arg codon (CGA) to the termination codon (TGA).</p><p><b>CONCLUSIONS</b>Aniridia is caused by a nonsense mutation of PAX6 gene in the large Chinese kindred. Genetic test is important to prevent the transmission of aniridia to their offsprings in the kindred by prenatal diagnosis.</p>

The ultrastructure study of membrane surface of the bone marrow CD34+ cells with the atomic force microscope / 中国实验血液学杂志

Human CD34(+) hematopoietic cells, a distinctive cell population containing hematopoietic stem/progenitor cells (HSPC), have the capability to highly self-renewal, differentiation into all lineages of committed progenitor cells and reconstitution of both long-term hematopoiesis and immunefunctions after transplantation. CD34(+) hematopoietic cells from bone marrow (BM) recently have been employed for treating neoplastic and genetic disorders. This study was aimed to investigate membrane surface ultrastructures of bone marrow CD34(+) cell from mormal persons and leukemia patients and to compare their morphologic differences by using atomic force microscope (AFM). BM was collected from 5 normal donors and 6 leukaemia patients. All samples were layered on Ficoll-Paque gradients (specific gravity 1.077 g/ml) to separate the mononuclear cells. After that CD34(+) cells were purified by immuno-magnetic bead separation and evaluated with a FACS Calibur, these cells were detected by AFM of tapping mode inair. At lest 20 cells per samples were observed. The results showed that most of CD34(+) hematopoietic cells were like circle plate, the diameter was 10 - 14 microm. The surface of CD34(+) hematopoietic cell membrane was comparatively complex. The surface of CD34(+) hematopoietic cell membrane appeared as granular, with packed particles. With the region analysis function of IP2.1 software, the region of 2 microm x 2 microm was selected and four parameters of the surface (maximum peak-to-valley distance, average roughness, root-mean-squared roughness and mean height) were measured. Values of the 4 parameters showed that the characteristic parameters of CD34(+) HSPC from leukaemia were higher than that from normal person. It is concluded that AFM has specific advantages in analyzing cell membrane in the nanometer level and can gain more information. With the help of analysis software, AFM can be a helpful tool for fast leukaemic diagnosis and CD34(+) hematopoietic cells selection.

Isolation, culture and multipotent differentiation of mesenchymal stem cells from human fetal livers / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To isolate and culture mesenchymal stem cells (MSCs) from human fetal livers and describe their biological characteristics.</p><p><b>METHODS</b>MSCs were acquired using an optimized method. Cell cycles and the immunophenotype of the cells were analyzed by flow cytometry. The osteogenic and adipogenic differentiations were induced and identified by specific stainings, and hepatic differentiation by morphology and RT-PCR.</p><p><b>RESULTS</b>The target cells derived from human fetal livers adhered to the plate with fibroblast-like morphology, whose surface markers were CD90, CD44, CD147 positive, and CD34, CD45, HLA-DR negtive. In the differentiation study, these cells could be induced to differentiate into osteogenic, adipogenic and hepatocyte-like cells.</p><p><b>CONCLUSION</b>Multipotent MSCs can be isolated and cultured from human fetal livers.</p>