Effects of Magnetic Rewarming on Mechanical Properties of Vitrified Umbilical Artery / 医用生物力学

Objective To study the effect of magnetic rewarming on the morphology and biomechanical properties of vitrified umbilical artery. Methods The vitrified umbilical artery was rewarmed by magnetothermal method and traditional water bath. The temperature distribution and stress in the solution system were analyzed, and the rewarming effect was evaluated by tissue staining and mechanical test. Results Compared with water bath rewarming, the temperature gradient and thermal stress generated by magnetic rewarming were smaller, which could effectively reduce the thermal stress damage during the rewarming stage and achieve rapid and uniform rewarming. Magnetic rewarming could effectively avoid umbilical artery fractures and micro-cracks. After rewarming, the extracellular matrix, collagen fibers, elastic fibers and muscle fibers of the umbilical artery were evenly distributed, which preserved the macro and micro structures of the umbilical artery. The umbilical artery showed different degrees of hardening after water bath and magnetic rewarming, but the elastic modulus and limit stress of the latter were not significantly different from those of fresh umbilical artery, and the latter had unidirectional stretching characteristics similar to that of fresh umbilical artery, showing good elasticity and toughness. Conclusions Compared with water bath rewarming, magnetothermal method can effectively reduce the damage of rewarming stage, ensure the macroscopic, microscopic structure integrity of umbilical artery and better biomechanical properties. The research findings provide important references for cryopreservation of large tissues or organs such as umbilical artery.

Gene expression profile changes induced upon umbilical cord mesenchymal cell infusion therapy in a rat model of hepatic cirrhosis / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate changes in gene expression that occur upon treatment with human umbilical cord mesenchymal stem cells (UC-MSCs) for hepatic cirrhosis using a rat model system.</p><p><b>METHODS</b>Hepatic cirrhosis was induced in Sprague-Dawley rats by subcutaneous injection of carbon tetrachloride and oral administration of alcohol.UC-MSCs were isolated from human umbilical cord and the cells' immunophenotype and differentiation towards osteogenic and adipogenic lineages were confirmed.The UC-MSC sample or vehicle alone (phosphate buffered saline, PBS) was transplanted by intravenous injection.Histopathological staining and serological testing were used to compare the liver morphology and function among the different groups.The gene expression in the PBS group and UC-MSC group were detected by gene microarray and differences between the groups were statistically analyzed by t-test.</p><p><b>RESULTS</b>Transplantation of the UC-MSCs improved liver function in the hepatic cirrhosis rats.Comparison of the gene expression profiles of the PBS group and the UC-MSC group showed that the latter had up-regulation of the genes related to the complement and coagulation cascades and down-regulation of the genes related to cell proliferation, cell cycle, and collagen synthesis.</p><p><b>CONCLUSION</b>UC-MSC therapy might improve liver function in cirrhosis by increasing the expression of genes related to the complement and coagulation cascades and by decreasing genes involved in cell proliferation and collagen deposition.</p>

Anti-aging function of placenta freeze-dried powder on mice / 中国生化药物杂志

Objective To investigate Anti-aging function of Placenta freeze-dried powder on mice. Method 2 month old female-KM mice were divided into five groups:normal control group, aging model group, positive control group, placenta freeze-dried powder low dose group and high dose group. Except normal control group,the rest of groups were treated with method of subcutaneous continuous injection of D-galactose for 42 days in order to establish mice aging model. Meanwhile, the corresponding drugs, via intragastric administration, were ingested by different treated groups and observe the change of immunity and physiological regulation related in mice. Results Compared with aging model group, thymus index and spleen index in placenta freeze-dried powder low dose group and high dose group increased obviously (P<0.05), content of MDA in brain decreased significantly (P<0.05), proportion of CD 4 and CD 8 lymphocyte in total lymphocyte, female hormone(P and E 2), IgG and haemopoietic factor in peripheral blood increased remarkably. Conclusion Placenta freeze-dried powder could slow the aging process on mice via immunity enhancement and improving physical regulation.

Differentiation of mesenchymal stem cell into epithelium and application / 国际儿科学杂志

Mesenchymal stem cells (MSC) is able to differentiate into a variety of epithelial cells,such as alveolar epithelium,tubular epithelium and corneal epithelial cells in vivo and in vitro under the given condition.After transfusion,MSC can effectively repair the injured lung epithelial cells,and relieve inflammation.MSC can also repair the renal tubular cell damage by reducing renal interstitial infiltration of inflammatory cells,promoting regeneration of renal tubular epithelial cells and inhibiting of apoptosis; Biological cornea can be available constructed by using MSC,which can availably repair the injured ocular surface.In the other hands,MSC can express keratinocyte growth factors and other cytokines,promoting limbal stem cell proliferation.In addition,MSC can also differentiate into pancreatic ductal epithelial cells,endometrial epithelial cells,spermatogenic epithelium and human retinal pigment epithelium.MSC has great application potential in epithelial diseases,and provide a good and effective choice in treatment of some epithelial diseases.