[A comparison study of post-cerebral hemorrhage stress ulcer with two interventional treatments aimed at endogenous endothelin in rat].

OBJECTIVE: To observe the respective effects of intervention either with endothelin (ET) antibody or with ET receptor antagonist on acute stress ulcer (ASU) subsequent to cerebral hemorrhage in rats. METHODS: Forty Sprague-Dawley (SD) rats were randomly divided into control group (group A, n=10), model group (group B, n=10), ET antibody (group C, n=10), and ET receptor antagonist group (group D, n=10). Right intracerebral hemorrhage was reproduced by injection of 200 microl autologous venous blood. Normal saline, ET antibody, or ET receptor antagonist was respectively administered intravenously per day for designated group. The rats were sacrificed at 3 days of the experiment. The incidence of ASU and ulcer index were assessed, serum ET-1 level, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in serum, Rsvmit (Rsv) and Vvmit (Vv) of cerebral and gastric mucosa were measured, and pathological examination of the cerebral tissue and gastric mucosa was performed with light microscopy and electron microscopy. RESULTS: In group B, serum ET-1 level did not changed. MDA content were markedly increased in serum, cerebral and gastric mucosa, SOD activity were markedly decreased, cerebral water content were markedly increased; Rsv in neuron and gastric parietal cell, Vv in gastric parietal cell both were markedly decreased (P<0.05 or P<0.01). ASU was only observed in group B (the incidence was 30%, ulcer index was 15). It was not observed in other groups. Compared with group B, MDA content were significantly decreased, and SOD activity were significantly increased in serum, cerebral and gastric mucosa in groups C and D, cerebral water content in group C were dramatically decreased (all P<0.01), but these were not statistically different between groups C and D. Rsv and Vv in neuron and gastric parietal cell in groups B, C and D were not statistically different, and serum ET-1 level were not statistically different among the groups (all P>0.05). CONCLUSION: Intervention of ET antibody and ET receptor antagonist can both reduce occurrence and development of ASU subsequent to cerebral hemorrhage in rats.

[EphrinB2 gene transfection promotes the differentiation of bone marrow mesenchymal stem cells into vascular endothelial cells].

OBJECTIVE: To study the effects of ephrinB2 gene transfection on the differentiation of bone marrow mesenchymal stem cells (BMSCs) into vascular endothelial cells. METHODS: Wistar rat BMSCs were isolated by density gradient centrifugation and purified on the basis of their adhesion ability. The BMSCs were transfected with a lenti-virus vector encoding a constitutively active form of human ephrinB2 gene, and the cell markers including CD105, CD73, CD44, von Willebrand factor (VWF) and vascular growth factor receptor 2 (KDR) were detected using flow cytometry. The potential of ephrinB2-BMSCs for differentiation into osteoblasts and adipoblasts in vitro were tested, and the differentiation of the cells into endothelial-like cells was induced by culture in the presence of 2% fetal bovine serum and 50 ng/ml vascular endothelial growth factor. RESULTS: EphrinB2-BMSCs were positive for the markers CD105, CD73 and CD44, and negative for the typical endothelial markers like VWF and KDR, and retained high potentials for differentiation into osteoblasts and adipoblasts in vitro after cultivation in respective media. After induced differentiation, ephrinB2-BMSCs expressed VWF and KDR and showed greater ability of differentiation into vascular endothelial cells and formation of capillary structures on matrix gel than the BMSCs without transfection. CONCLUSIONS: EphrinB2 gene transfection efficiently promotes the differentiation of BMSCs into vascular endothelial cells. These genetically engineered cells provide valuable sources for new therapies of coronary heart disease.

[Genetic diagnosis and prenatal genetic diagnosis of fragile X syndrome].

In order to obtain a simple,fast,accurate and low-cost diagnosis method of fragile X syndrome, cytogenetic tests and molecular genetic tests were carried out with direct amplification of (CGG)(n) repeat sequence in 5' terminal of FMR1 gene by PCR and the cDNA sequence of FMR1 by RT-PCR from six mental retardation pedigrees. The proband of pedigree A with high expression of fragile X chromosome(35/273) was detected to be a full mutation patient of fragile X syndrome by the molecular genetic test. There is no expression of fragile X chromosome in the proband and his mother of pedigree B, which was further confirmed as a non-fragile X pedigree by the molecular genetic test. A male foetus of the pedigree C has fragile X chromosome(5/93), but the proband and his mother has no fragile X chromosome. By further detection using molecular genetic test, the male foetus is a full mutation patient of fragile X syndrome, his mother is a permutated carrier, and his brother is a mosaic patient. The proband of pedigree D has high expression of fragile X chromosome (17%), his sister also has expression of fragile X chromosome (5%). By further detection with molecular genetic test, the proband is a full mutation patient of fragile X syndrome,and his sister is a mosaic patient. The probands of pedigrees E and F of the mother were found with suspicions fragile X chromosome, being confirmed as the non-fragile X pedigrees by the molecular genetic test. The conclusion is that the analysis test with direct amplification of 5'j(CGG)n repeat sequence and cDNA sequence in FMR1 gene is simple,fast,low-cost and can be applied in screening, diagnosis and prenatal diagnosis of fragile X syndrome.