ABSTRACT
Objective To analyze and evaluate the effects of the tissue engineering bladder reconstruction on the upper urinary tract structure and function.Methods The 8 male beagles were randomly divided into the two groups:sham-operation group (group A,n=4)and the collagen scaffold repair group (group B,n=4).The bladder defect animal model was established in the group B by using the collagen scaffold materials to repair the bladder.The renal function related biochemical indicators were detec-ted and the renal Doppler ultrasonic examination was performed in each group before repair and in 23 weeks after repair.The speci-mens from the two groups were performed the gross morphology observation and the histology examination on postoperative 24 weeks.Results The renal Doppler ultrasound examination showed the normal kidney morphology and normal blood flow signal.In the general observation,no calculi and neoplasm were found in the kidney and ureter of the experimental dogs.The renal function related biochemical indicators had no statistically significant differences between the two groups(P>0.05).The histological exami-nation indicated that the organization structure was integrity,the nephrons in each group had no obvious pathological changes.Con-clusion Using the collagen scaffold materials to reconstruct the canine bladder has no adverse influence on the upper urinary tract structure and function,this tissue engineering approach has good feasibility.
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BACKGROUND: Researches show that erythropoietin (EPO) can stimulate the proliferation and protraction of endothelial progenitor cells to form new vessels, so EPO may play an important role in proliferation and differentiation of bone marrow-derived mesenchymal stem cells (MSCs). OBJECTIVE: To explore the effects of EPO on the proliferation and cell cycle of MSCs. DESIGN, TIME AND SETTING: From July to November 2007, the observation of comparative cell trial was performed at the Hematologic Diseases Institute of General Hospital Lanzhou Military Area Command of Chinese PLA. MATERIALS: Bone marrow liquid specimens were provided by voluntary donors. The informed consents were obtained from all patients, and the experiment was approved by Hospital Ethics Committee. METHODS: Using Percoll solution, MSCs were isolated from bone marrow by the method of density centrifugation. Flow cytometry was applied to detect the cell cycles of the second and third passages. MSCs were incubated with different doses of EPO (0.25, 0.50, 1.00, 2.00, 5.00 U/mL) in serum free culture media, and cells cultured with no EPO were regarded as control. All cells were cultured for 24, 48, and 72 hours. MAIN OUTCOME MEASURES: ①Proliferation of MSCs was measured by MTT assays after 24, 48, and 72 hours; ②Cell cycle was measured by flow cytometry assays after incubated with 10 U/mL EPO for 72 hours. RESULTS: After MSCs was incubated with EPO, the cell proliferation index was significantly increased in a dose and time dependent manner. The effects on the proliferation of MSCs were highest in 5 U/mL group. Compared with the control group, EPO could significantly decrease G0 /G1 ratio, and increase S and G2/M stage ratio (P
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BACKGROUND: No particular marker molecule of bone marrow mesenchymal stem cells (BMSCs) is presently found, so its determination is difficult. BrdU marker has no radioactive pollution. Some studies have confirmed that BrdU marker has no damage to cell function without ultraviolet radiation. OBJECTIVE: To investigate in vitro identification and labeling methods and biological characteristics of adult BMSCs. DESIGN, TIME AND SETTING: The cell experiment was conducted at the General Hospital of Lanzhou Military Area Command of Chinese PLA between June and December 2007. MATERIALS: Bone marrow was collected from 5 healthy adult volunteers. BrdU was purchased from Sigma, USA. METHODS: 10 mL adult bone marrow was harvested to isolate mononuclear cells by density gradient. Cells were cultured in DMEM containing 10% fetal bovine serum and proliferated at a density of 2?108 L-1. At the third passage, BMSCs was inoculated in medium supplemented with osteoblast inductor and stained with alkaline phosphatase. Subsequently, BMSCs were inoculated in medium supplemented with lipoblast inductor and stained with oil red O. Cells were incubated with BrdU at different concentrations of 5, 10 and 15 ?mol/L for 12, 24, 48, 72 and 96 hours, and then detected by immunocytochemistry. MAIN OUTCOME MEASURES: Cell growth and proliferation were observed under an inverted light microscope. Cell phenotype, osteoblast and lipoblast differentiation were identified by flow cytometry. BrdU-positive labeling rate and cell growth after labeling were investigated. RESULTS: In vitro cultured BMSCs were homogenous population and exhibited a spindle-shaped fibroblastic morphology. BMSCs expressed CD44 and CD71, but did not express CD34 and HLA-DR. BMSCs can differentiate into osteoblasts and lipoblasts. Most BMSCs were labeled by BrdU. With the increase in labeling concentration and over time, BrdU positive rate gradually increased and exceeded 90% after labeling with BrdU (10 ?mol/L) for 72 hours, with the labeling identifiable in nine consecutive passages. At the third passage, 90% BMSCs were in G0/G1 phase, and 88.62% in G0/G1 phase after labeling. BrdU has little effect on morphous and proliferation of labeled cells. CONCLUSION: Adult BMSCs can be identified through morphological character, specific surface antigens and multipotential differentiation in vitro. BrdU labeling provides a feasible means for a dynamic observation of the survival, growth and differentiation of the implanted BMSCs. The optimal dosage and timing of BrdU labeling are respectively 10 ?mol/L and 72 hours.