Effects of CANELIM capsule drug-contained serum on viscoelasticity and adhesive mechanical properties of cholangiocarcinoma cells / 生物医学工程学杂志

By way of gastrogavage, we administered CANELIM capsules to rat for prepering the drug-contained serums. And then the serums obtained were used to plant cholangiocarcinoma cells. Lastly, using the micropipette aspiration technique, we investigated the effects which the drug-contained serums of different doses have on the viscoelasticity and adhesive mechanical properties of cholangiocarcinoma cells. The results showed that cholangiocarcinoma cells presented a characteristic of high elastic coefficient and low viscous coefficient. After being treated by the high dose and middle dose drug-contained serums, the viscoelastical properties of cholangiocarcinoma cells K1, K2 and micro evidently decreased (P < 0.01). But the properties of low dose did not evidently change. The adhesive force between cholangiocarcinoma cells and CD44v6 protein significantly reduced with the increasing of the dose of CANELIM capsules (P < 0.01). It is suggested that CANELIM capsules would destroy the cytoskeleton of cholangiocarcinoma cells, restrain the adhesion molecule CD44v6 on membrane from expressing, reduce the adhesion probability between cholangiocarcinoma cells and vasal endothelial cells, and finally, prevent the metastasis of cholangiocarcinoma cells.

Establishment of a mechanical experimental system of biologic tract tissue with auto-measurement based on measuring mark / 生物医学工程学杂志

As the core of mechanical experimental system of biologic tract tissue, the automatic measuring program of serial images based on measuring mark could provide two basic parameters for mechanical analysis, namely tissue length and average external diameter. Hybrid programming between VC+ + and Matlab is conducted. Subprogram will be in charge of the processing of single image (color-gray transform, image segmentation, pick-up target area according to measuring mark), while the main program written by VC+ + will orderly call the above subprogram again and again when it is traversing through the image sequence which records the process of a tissue's expansion and constriction under force, so the automatic measure of the serial images and mechanical analysis is achieved. The results showed: the experimental system could avoid the contrived errors caused by naked eye identification and manual choosing measuring area; the measuring precision could satisfy the need of tract tissue mechanical analysis; the system could save time and energy dramatically. The fact of tract tissue accords with the applicable conditions of mechanical analysis theory used in our experimentations.

Study on biomechanical properties of several scaffold materials for tissue engineering / 中国组织工程研究

BACKGROUND:It is still a research focus on constructing substitution of the human tissues and organs, or producing the alliance for grafting by engineering methods in tissue engineering. Among these researches, it is pivotal to choose appropriate materials. The prepared scaffolds should have suitable tensile strength and mechanical toughness to withstand the various outside forces without being damaged. So, it is very necessary to evaluate the biomechanical properties of candidated materials in tissue engineering, which can supply the references for selecting materials for tissue scaffolds and their designation.OBJECTIVE: To investigate the biomechanical properties of nine kinds of scaffold materials, in order to supply a biomechanical basis for the selection and design of scaffold materials for tissue engineering.DESIGN: A repetitive measurement study.SETTING: College of Bioengineering, Chongqing University.MATERIALS: The materials involved in this study were poly (DL-lactic-co - glycolic acid) (PLGA), sodium polymannuronate, gelatine, chitosan, collagen, acellular porcine dermis (APD), acellular vascular matrix (AVM),APD-PLGA, AVM-PLGA, modified gelatine and chitosan.METHODS: All the experiments related to this study were completed in the Biorheology laboratory of the College of Bioengineering, Chongqing University from April 2006 to March 2007. The nine materials above were prepared, gelatine and chitosan were modified. Stress-strain testing was performed at 10 mm per minute by a material testing machine (INSTRON 1011, USA). The Yang's modulus was calculated in the range of 0.005 to 0.02, the ultimate strain and stress were also obtained.MAIN OUTCOME MEASURES: The ultimate strain, ultimate stress and Yang's modulus of the nine materials were analyzed.polymannuronate ＞ AVM-PLGA ＞ collagen ＞ gelatine (P ＜ 0.05). The rate of burst straining of chitosan and PLGA were greater than those of other materials, 133% and 276% respectively (P ＜ 0.05). In addition, after being combined with ultimate stresses of APD and APD-PLGA were greater than that of other materials, i.e., their burst strengths were greater than those of other materials. The data also indicated that the burst strength of APD-PLGA was a little greater than that of APD (P ＞ 0.05). The burst strengths of gelatin, chitosan, and collagen were similar at the range of 7.67 to 9.51 MPa (P ＞ 0.05). The burst strengths of collagen and sodium polymannuronate were from 1.16 to 1.40 MPa, which were the least among all the materials. At the same time, being combined with PLGA, the burst strength of AVM-PLGA greatest, i.e., its rigidity was the greatest. The rigidity of APD was the least. After combined with PLGA, the rigidity of AVM and APD were increased (P ＜ 0.05), and corresponded with PLGA (P＞ 0.05). Except for gelatin, the order of rigidity in the materials was AVM-PLGA ＞ PLGA ＞ APD-PLGA ＞ AVM ＞ chitosan ＞ sodium polymannuronate ＞ collagen ＞ APD.CONCLUSION: AVM and APD have good biomechanical properties, which are very different from the water-soluble collagen. It is promising to improve the biomechanical properties of sodium polymannuronate, gelatin and chitosan by the complex of PLGA.

Correlation between cyclin A gene expression in adult patients with acute leukemia and drug resistance / 华中科技大学学报（医学）（英德文版）

In order to investigate the relationship between the expression of cyclin A and drug resistance in adult patients with acute leukemia (AL), the mRNA expression of cyclin A, mdr1, Top II alpha, bcl-2 was detected in 64 adult patients with AL and 20 normal controls by semi-reverse transcription polymerase chain reaction (semi-RT-PCR). It was found that the cyclin A and Top II alpha mRNA expression levels in drug resistant group were significantly lower than in sensitive group (P < 0.01). Under the same experimental condition no cyclin A mRNA expression was detectable in all normal controls. The mdr1 and bcl-2 mRNA expression levels in resistant group were significantly higher than in sensitive group (P < 0.01), cyclin A and Top II alpha gene expression levels were closely correlated (rs = +0.794, P = 0.000, n = 64) in all AL patients, but cyclin A was not correlated with mdr1 and bcl-2 gene expression levels. In drug resistant group there was a negative correlation between the gene expression levels of cyclin A and mdr1 (rs = -0.337, P = 0.029). The 10 AL patients with positive lower expression of both cyclin A and Top II alpha were all resistant to drugs. Logistic regression of Binary analysis showed the correlation between the lower expression of cyclin A and drug resistance. It was concluded that lower expression of cyclin A gene might be an unfavorable prognostic factor for patients with AL, and detection of both cyclin A and Top II alpha gene expression would predict drug resistance in AL patients.

Characteristics of tenocyte adhesion to biologically-modified surface of polymer / 生物医学工程学杂志

In this study we examined the in vitro characteristics of tenocyte adhesion to biologically-modified surface of polymer. Polylactic-co-glycolic acid (PLGA) 85/15 films were prepared by a solvent-casting technique. Each film was adhered onto the bottom of a chamber. The film was precoated with poly-D-lysine (PDL), and then coated with serum-free F12 medium containing various concentrations of fibronectin (FN), type I collagen (CN I), and insulin-like growth factor1 (IGF-1). The monoclonal antibodies (to FN and to CN I) with various dilutions were used to inhibit attachment of tenocytes to surface precoated with FN or CN I. Human embryonic tendon cells (HETCs) and transformed human embryonic tendon cells (THETCs) were used as the seeding cells. The system used for the measurement of adhesion force was the micropipette aspiration experiment system. The micropipette was manipulated to aspirate a small portion of the tenocyte body by using a small aspiration pressure. Then the pipette was pulled away from the adhesion area by micromanipulation. The minimum force required to detach the tenocyte from the substrate was defined as the adhesion force. The results showed that modification of FN or CN I by precoating significantly enhanced attachment of tenocytes to surface of polymer (P < 0.05). As antibodies to FN or CN I were added to a polymer film precoated with FN or CN I, the adhesion force decreased significantly (P < 0.05). We concluded that the specific adhesion forces of tenocytes to extracellular matrix adhesion proteins (FN and CN I) had coordinated action and showed good dependence on their precoating concentrations, and were inhibited by the antibodies to these adhesion proteins. Films precoated with IGF-1 strongly accelerated the adhesion of tenocytes to polymer. These results indicate that the specific adhesion of tenocytes to polymer can be promoted by coating extracellular matrix adhesive proteins and insulin-like growth factor1. It is of great importance to construct tissue-engineered tendon.

The correlation of cyclin A gene expression with drug resistance in adult acute leukemia patients / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the relationship between the expression of cyclin A and drug resistance in patients with adult acute leukemias.</p><p><b>METHODS</b>The mRNA expressions of cyclin A, mdr1, Topo II alpha and bcl-2 were measured in 64 patients with adult acute leukemia (AL) and 20 normal subjects by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>(1) The cyclin A and Topo II alpha mRNA expression levels in the treatment resistant group were significantly lower than that in the sensitive group (P < 0.01). There was no cyclin A mRNA expression in the 20 normal subjects under the same experiment condition. (2) The mdr1 and bcl-2 mRNA expression levels in the resistant group were significantly higher than that in sensitive group (P < 0.01). (3) Cyclin A and Topo II alpha gene expression levels were positively correlated (r = 0.794, P = 0.000) in the 64 AL patients, and there was a negative correlation between the gene expression levels of cyclin A and mdr1 (r = -0.337, P = 0.029) in the drug resistant group. (4) Ten AL patients with low expressions of both cyclin A and Topo II alpha were all in the resistant group. Logistic regression of binary analysis showed a significant correlation between the low expression of cyclin A and drug resistance.</p><p><b>CONCLUSION</b>Low expression of cyclin A gene might be a unfavorable prognostic factor for patients with AL and measurement of both cyclin A and Topo II alpha gene expression would predict drug resistance for AL patients.</p>

The study of cyclin A antisense oligodeoxynucleotides on proliferation regulation of K562 cell / 中国输血杂志

Objective To investigate the effect of cyclin A antisense oligodeoxynucleotide (ASON) on mediating proliferation of K562 cell. Method After in vitro co-culture of cyclin A ASON with K562 cell, cyclin A protein expression levels were measured by flow cytometry. Cell growth was detected by trypan blue dye exclusion and colony-forming experiment. Results In cyclin A ASON group, cyclin A protein expression was significantly inhibited, compared to those in sense oligodeoxynucleotide (SON) group and blank group. Moreover, when the ASON concentration increased, the proliferation ratio of K562 cells and the CFU- K562 were significantly inhibited. Conclusion Cyclin A ASON can specifically inhibit cyclin A protein expression as well as inhibit the K562 cell proliferation and can lead to leukemic cell apoptosis. The effect of cyclin A ASON is concentration dependent.

Effect of cyclin B1 antisense oligodeoxynucleotides with liposomal transfection on proliferation of HL60 cells / 中国病理生理杂志

AIM: To investigate the effect of cyclin B1 antisense oligodeoxynucleotide (ASON) with liposomal transfection on proliferation of HL60 cells. METHODS: After cyclin B1 ASON with liposomal transfection was used in vitro co-culture with HL60 cells,the protein and mRNA expression levels of cyclin B1 were measured by flow cytometry and RT-PCR. The cell apoptosis was detected by electron microscopy, in situ cell apoptosis detection kit (POD),DNA agarose gel electrophoresis and flow cytometry. RESULTS: In cyclin B1 ASON group the protein and mRNA expression levels of cyclin B1 were significantly inhibited than those in sense oligodeoxynucleotide (SON) group and blank group. Morever,when the ASON concentration increased,the proliferation ratio of HL60 cells and CFU-HL60 clony unit were also significantly inhibited. The apoptosis of HL60 cells was also observed. CONCLUSION: Cyclin B1 ASON specifically inhibited its protein and mRNA expression levels as well as the HL60 cell proliferations and induced leukemia cell apoptosis. It's effect depended upon the concentration of ASON.