ABSTRACT
BACKGROUND: One of the difficulties and hot topics in the field of computer vision and image processing is extraction of the high-level pulmonary trachea from patients' lung CT images. Current, common bronchial extraction methods are limited by the phenomenon of bronchial loss and leakage, and cannot extract the higher-level pulmonary trachea, which does not meet the requirements of guiding lung puncture procedures. METHODS: Based on the characteristic "tubular structure" (ring or semi-closed ring) of the pulmonary trachea in CT images, an algorithm based on dynamic tubular edge contour is proposed. In axial, coronal and sagittal CT images, the algorithm could extract the skeletal line of the pulmonary trachea and vessel-connecting region, perform elliptical fitting, extract the pulmonary trachea by the ratio of the ellipse's long and short axes, and obtain point cloud data of the pulmonary trachea in three directions. The point cloud data was fused to obtain a complete three-dimensional model of the pulmonary trachea. RESULTS: The algorithm was verified using CT data from "EXACT09", and could extract the pulmonary trachea to the 10-11 level, which effectively solves the problems of leakage and loss of the trachea. CONCLUSIONS: We have constructed a novel extraction algorithm of pulmonary trachea that can guide the doctors to decide the puncture path and avoid the large trachea, which has important theoretical and practical significance for reducing puncture complications and the mortality rate.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the feasibility of constructing a skin tissue engineering covering on chitinous membrane using rat epidermal stem cells (ESCs).</p><p><b>METHODS</b>Rat ESCs were isolated and cultured by cold digestive method and collagen type IV adherent method. Cell colonies were observed with inverted microscope. Expressions of DNA and RNA of ESCs were detected with laser scanning confocal microscope. Growth curves of cells were determined with Alamar BlueTM colorimetric method. Expressions of surface markers of ESCs (CD29, CD71, CD49d, and CD34) were detected with flow cytometer. Positive expressions of CK15, CK19, and P63 of ESCs were determined by immunohistochemistry. Influence of original chitinous membrane leachate in different dilutions on ESCs was observed. Condition of growth of ESCs on the vehicle was observed.</p><p><b>RESULTS</b>Isolated cultured cells were verified as ESCs, of which the doubling generation time was 48 hs. CD29 and CD49d were positive; CD71 and CD34 were negative; CK19, CK15, and P63 were positive. Compared with that of control group, ESCs cultured in chitinous membrane leachate showed slight cell proliferation when diluted to 1:8-1:512 dilutions, but there was no statistically significant difference (P > 0.05). The checkerboard-form cell colonies of ESCs could be visualized with naked eyes on the chitinous membrane in 2-4 weeks of culture. A multitude of ESCs were seen to grow on fibres under microscope.</p><p><b>CONCLUSIONS</b>Chitinous membrane may be used as ESCs culture vehicle, and biological compatibility is good.</p>
Subject(s)
Animals , Female , Male , Rats , Cell Culture Techniques , Methods , Cellular Structures , Chitin , Epithelial Cells , Cell Biology , Stem Cells , Cell Biology , Tissue Engineering , Methods , Tissue ScaffoldsABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of basic fibroblast growth factor (bFGF) and hyaluronic acid (HA) on the proliferation of rabbit chondrocytes in vitro.</p><p><b>METHODS</b>Chondrocytes from the knee joints of New Zealand white rabbits were cultured. bFGF or HA or both were added into the culture medium respectively, and the proliferation of the chondrocytes was measured with MTT 3-(4, 5-dimethylthiazol-2-yl) 2, 5-diphenyl-tetra-zolium bromide. (MTT, Sigma, M2128).</p><p><b>RESULTS</b>Basic fibroblast growth factor (10 ng/ml) with low concentration of fetal bovine serum in the culture medium promoted the proliferation of chondrocytes significantly, and this effect reached its maximum when concentration of bFGF reached 50 ng/ml. HA itself had no effect on the proliferation of chondrocytes. However, when bFGF was used in combination with HA, especially when the concentration of bFGF was 50-500 ng/ml and that of HA was 10-50 ng/ml, the effect on the proliferation of chondrocytes was much more than when bFGF or HA was used alone.</p><p><b>CONCLUSIONS</b>bFGF can promote the proliferation of chondrocytes. HA, which has no effect on the proliferation of the cells, can maintain a normal growth of chondrocytes. When bFGF is used in combination with HA, more proliferation is obtained.</p>
