Galectin-3 enhances proliferation and angiogenesis of endothelial cells differentiated from bone marrow mesenchymal stem cells.

PURPOSE: To observe the effects of galectin-3 on proliferation and angiogenesis of endothelial cells differentiated from bone marrow mesenchymal stem (MSCs). METHODS: Cultured MSCs were isolated from bone marrow of Sprague-Dawley rats and purified by gradient centrifugation with lymphocytes separation medium. Cells of passage 3 were differentiated into endothelial cels by vascular endothelial growth factor and basic fibroblast growth factor. These cells were identified as endothelial cells by immunohistochemistry staining and electronic microscopy after 14 days. The cells were cultivated with the galectin-3 at the concentrations of 0.1, 1, and 5 µg/mL for 24 hours. The proliferation of endothelial cells were measured by 3-(4,5-methylth-iazol-2-yl)-diphenyltetrazolium bromide (MTT) and the cell cycle was investigated by using flow cytometry. The functionality of angiogensis was observed when the cells appeared tube formation in presence of glacetin-3. RESULTS: The proliferation activity, analyzed by MTT method, in the galectin-3 groups (1 and 5 µg/mL) were 0.3002±0.0159 and 0.3514±0.0133, respectively, which were significantly greater than that in the control group (0.2339±0.0041; P<.05). Flow cytometry detection showed that S phase cells (%) are 29.42±0.45, 34.56±0.82, and 52.58±2.84 in groups of 0.1, 1, and 5 µg/mL, respectively, and G2M phase cells increased from 4.88±1.12 to 5.26±0.45 with the concentrations of 1 and 5 µg/mL, respectively, which demonstrated significant difference compared with the control group (P<.05). The tubular network formation was lengthened significantly compared with the control group (P<.05). CONCLUSION: Galectin-3 can promote the proliferation and angiogenesis of endothelial cells differentiated from bone marrow mesenchymal stem cells.

Chaotic micromixers using two-layer crossing channels to exhibit fast mixing at low Reynolds numbers.

We report two chaotic micromixers that exhibit fast mixing at low Reynolds numbers in this paper. Passive mixers usually use the channel geometry to stir the fluids, and many previously reported designs rely on inertial effects which are only available at moderate Re. In this paper, we propose two chaotic micromixers using two-layer crossing channels. Both numerical and experimental studies show that the mixers are very efficient for fluid manipulation at low Reynolds numbers, such as stretching and splitting, folding and recombination, through which chaotic advection can be generated and the mixing is significantly promoted. More importantly, the generation of chaotic advection does not rely on the fluid inertial forces, so the mixers work well at very low Re. The mixers are benchmarked against a three-dimensional serpentine mixer. Results show that the latter is inefficient at Re = 0.2, while the new design exhibits rapid mixing at Re = 0.2 and at Re of O(10(-2)). The new mixer design will benefit various microfluidic systems.

Extraction of the hepatic vasculature in rats using 3-D micro-CT images.

High-resolution micro-computed tomography (CT) scanners now exist for imaging small animals. In particular, such a scanner can generate very large three-dimensional (3-D) digital images of the rat's hepatic vasculature. These images provide data on the overall structure and function of such complex vascular trees. Unfortunately, human operators have extreme difficulty in extracting the extensive vasculature contained in the images. Also, no suitable tree representation exists that permits straight-forward structural analysis and information retrieval. This work proposes an automatic procedure for extracting and representing such a vascular tree. The procedure is both computation and memory efficient and runs on current PCs. As the results demonstrate, the procedure faithfully follows human-defined measurements and provides far more information than can be defined interactively.

Changes in plasma fibronectin levels in burn patients.

Plasma fibronectin was determined in 180 healthy individuals. No significant difference was found between males and females: therefore the values were pooled. The mean value was 286.94 +/- 51.35 micrograms/ml. In 24 patients with burns covering 30-95 per cent of the total body surface area (TBSA), plasma fibronectin was determined sequentially. There was a significant lowering in plasma fibronectin (FN) values in all cases on post-burn day 1 (112.56-185.85 micrograms/ml) and post-burn day 2 (44.03-298.0 micrograms/ml). The concentrations returned to within the normal range in 19 survivors within 3-6 days. In five non-survivors, plasma FN levels fell progressively until death. In another nine patients with burns ranging from 3 per cent to 25 per cent TBSA, plasma FN level was found to be normal on post-burn day 1. The likely causes of the reduced concentrations of plasma fibronectin in patients with burn injuries are briefly discussed. It seems that the level of plasma fibronectin may be used as a prognostic index in burn patients.