One-dimensional consolidation of highly saturated abandoned-soil under time-dependent stress: An analytical study.

A thorough knowledge of the consolidation behavior of highly saturated soil under time-dependent stress is essential for the design and construction of abandoned-soil dump sites in the soft soil regions of China. In this study, one-dimensional consolidation analytical solutions are derived for such soil under one-way and two-way drainage conditions, accommodating the time-dependent stress created by various dumping protocols. Representative soil samples are obtained, and consolidation tests are conducted with various saturation degrees (one-way drainage) and loading protocols (two-way drainage), to verify the consolidation equation and determine its range of applicability to various saturation degrees. The effects of layer thickness, dumping type, and compaction degree on the consolidation behaviors of highly saturated abandoned-soil dumps are investigated. The one-dimensional consolidation equation is applicable to soil with saturation degree not lower than 75% under instantaneous stress, stepped stress, and linear stress. The pore pressure distribution with depth is not symmetrical; the eccentric distance of consolidation degree increases with increasing layer thickness in the stress application stage and is approximately zero in the stress keeping stage. The pore pressure at middle of the soil layer increases with increasing layer thickness and decreases with increasing dumping rate from the completion of soil dumping. With increasing compaction degree, the middle pore pressure increases, while the surface settlement decreases. In the premise of the stability of an abandoned-soil dump, where the goals are to reduce post-construction settlement and to shorten the consolidation process of the entire soil layer, the important factors are smaller layer thickness, higher dumping rate, and larger compaction degree.

Synergistic effects of alpha-1,2-fucosyltransferase, DAF, and CD59 in suppression of xenogenic immunological responses.

BACKGROUND: Previous studies showed that alpha-1,2-fucosyltransferase (HT), decay accelerating factor (DAF), and CD59 have an inhibitory effect on the immunological rejection of xenogenic transplantation. METHODS: To investigate their possible synergistic effects in suppression of heterogeneic transplantation, we produced transgenic mouse lines expressing human HT, DAF, and/or CD59 by the standard pronuclear injection approach. PCR and Southern blot were used to identify the transgenic founder lines. Flow cytometry confirmed the high-level expression of HT, DAF, or CD59 in the transgenic mice. RESULTS: The deposition of IgM, C3c, or C9 in the cardiac vascular endothelial cells of the HT, HT/CD59, and/or DAF multiple positive transgenic mice was markedly decreased. The survival time and function of the hearts of the co-transgenic mice were significantly longer and higher than that of the single HT-positive transgenic mice (P < 0.05). CONCLUSION: The mice co-expressing HT/DAF or HT/CD59 could resist the hyperacute rejection better than those expressing HT alone. It is feasible to use HT and C-reactive proteins co-transgenic tissues to resist hyperacute rejection and xenograft rejection.

[Gene profiling after knocking-down the expression of NS gene in prostate cancer PC-3 cells].

OBJECTIVE: To screen the genes and possible signal transduction pathways involved in the mechanism of nucleostemin (NS) in the proliferation of prostate cancer. METHODS: Oligonucleotide DNA microarray was used to screen the genome changes after knocking-down expression of NS in PC-3 cells and quantitative real-time PCR was used to further confirm the important differentially expressed genes. RESULTS: 219 differentially expressed genes were found and theses genes were involved in cell cycle, cell proliferation, signal transduction, cell apoptosis and cell differentiation, etc. INK4 family genes (p15, p16, p18) were up-regulated and cyclin D1, HDAC1 were down-regulated, the main action points were CDK4/6-cyclin D and pRb-E2F1 complexes. CONCLUSION: NS may promote the progression of prostate cancer by inhibiting the expression of p15, p16, and p18 in PC-3 cells. NS is an important G(1)/S checkpoint regulator and its regulatory activity has been certified at gene level.

[Silencing nucleostemin expression reduces the proliferation of PC-3 cells].

OBJECTIVE: To detect the expression of the nucleostemin (NS) gene in prostate cancer PC-3, LNCaP and DU145 cells, and to study the effect of the NS gene on the proliferation of PC-3 cells after its silencing. METHODS: The protein and mRNA expressions of NS in PC-3, LNCaP and DU145 cells were respectively detected by immunohistochemical staining and RT-PCR. An NS-specific short-hairpin RNA (shRNA) expression plasmid was used to transfect the PC-3 cells (NS-shRNA-PC-3), followed by observation of the changes of the NS gene and the proliferation and apoptosis of the cells. RESULTS: The NS gene was highly expressed in the three types of cells. After the transfection, the NS expression and the proliferation of the NS-siRNA-PC-3 cells were remarkably reduced, while the percentage of the GO/G1 cells and the early apoptosis of the PC-3 cells obviously increased. A marked decrease was observed in the neoplasm forming ability of the NS-siRNA-PC-3 cells in the nude mice. CONCLUSION: NS is highly expressed in prostate cancer cells. The proliferation of PC-3 cells is remarkably reduced and the early apoptosis of PC-3 cells increased after silencing the NS gene by NS-specific shRNA.

Expression of nucleostemin in prostate cancer and its effect on the proliferation of PC-3 cells.

BACKGROUND: Nucleostemin is essential for the proliferation and survival of stem and cancer cells, but it is unknown whether this newly identified molecule is involved in prostate cancer pathogenesis. METHODS: Total RNA and protein were extracted from prostate cancer tissues and PC-3, LNCap and DU145 cell lines. The nucleostemin mRNA and protein expression were measured by RT-PCR and Western blot. Immunohistochemistry was also used to detect the nucleostemin protein expression in prostate cancer tissues and PC-3 cells. A nucleostemin specific, short hairpin RNA, expression plasmid was used to transfect PC-3 cells. The changes of nucleostemin gene were detected and the proliferative capacity of the cells was determined. RESULTS: Nucleostemin was highly expressed in prostate cancer tissues and cell lines. Nucleostemin expression level in the silencer group PC-3 cells remarkably reduced. The proliferation rate of silencer group PC-3 cells decreased and the percentage of G1 stage cells increased. The neoplasm forming capacity in nude mice of the silencer group PC-3 cells decreased significantly. CONCLUSIONS: Nucleostemin is highly expressed in prostate cancer tissues and cell lines. The proliferative capacity of PC-3 cells is remarkably reduced after silencing nucleostemin gene expression.

[Intravesical perfusion of recombinant adeno-associated virus-endostatin in treatment of bladder cancer: experiments with mice].

OBJECTIVE: To study the anti-tumor effect of intravesical perfusion of recombinant adeno-associated virus-endostatin (rAAV-ES) in treatment of bladder cancer. METHODS: Forty-five C57BL/6 mice underwent intravesical perfusion of mouse bladder cancer cells of the line MB49 so as to establish orthotopic murine bladder cancer models and were divided into 3 equal groups, 3 days later to undergo intravesical perfusion of rAAV-ES, rAAV-EYFP, and PBS respectively once per week for 6 times. The anti-tumor effect of rAAV-ES on the tumor bearing mice was studied. RESULTS: The tumor weight of the rAAV-ES group was (145 +/- 30) mg, significantly lighter than those of the rAAV-EYFP and PBS groups [(250 +/- 32) mg and (250 +/- 30) mg respectively, both P < 0.05]. The survival time of the rAAV-ES-treated mice was (46 +/- 7) d, significantly longer than those of the rAAV-EYFP- and PBS-treated groups [(38 +/- 7) d and (38 +/- 6) d respectively, both P < 0.05]. CONCLUSION: An effective biologic agent in bladder cancer gene therapy, intravesical treatment with rAAV-ES inhibits the angiogenesis, thus inhibiting the tumor formation and progression.

[Expression of nucleostemin in prostate cancer tissues and its clinical significance].

OBJECTIVE: To explore the expression of the nucleostemin (NS) gene in prostate cancer (PCa) tissues and its clinical significance. METHODS: We detected the NS expression in PCa, benign prostatic hyperplasia (BPH) and high grade prostatic intraepithelial neoplasia (HGPIN) tissues by RT-PCR and immunohistochemistry, and analyzed the correlation between the expression of the NS protein and the clinical variables of PCa. RESULTS: The NS mRNA level was markedly higher in the PCa than in the BPH tissues. The rates of strongly positive, positive and weakly positive expressions of the NS protein were 48.8%, 36.6% and 12.2% in PCa, 4.0%, 32.0% and 56.0% in BPH, and 5.0%, 25.0% and 60.0% in HGPIN, respectively. The expression level of the NS protein was significantly higher in PCa than in BPH and HGPIN (P < 0.05). The expression of the NS gene was negatively correlated with the degree of cell differentiation in the PCa tissues, the worse the differentiation, the higher the NS expression level. CONCLUSION: The NS gene is highly expressed in PCa tissues and may have an important role in the adverse differentiation and malignant proliferation of prostate cancer.

[Gene therapy of bladder cancer by using recombinant adeno-associated virus-endostatin: experiments in vitro and in vivo].

OBJECTIVE: To package recombinant adeno-associated virus-endostatin (rAAV-ES) and study its anti-tumor effect in vitro and in vivo. METHODS: rAAV-ES was packaged with co-transfection technique and transfected into the human bladder cancer cells of the line EJ. 24 h later ELISA was used to examine the concentration of ES in the supernatant. The inhibition of human umbilical veins endothelial cells (HUVECs) chemotactic movement were examined by Transwell system. Nude Balb/c mice were divided into 4 groups: (1) 5 mice were inoculated with the EJ cells transfected with rAAV-ES or rAAV-enhanced yellow fluorescence protein (rAAV-EYFP) for 3 days to the subcutaneous tissues of bilateral shoulders so as to observe the growth of tumor. (2) 24 mice were injected with rAAV-ES intramuscularly and then the serum ES was examined every 10 days since the 10 th day after the injection. (3) 36 mice were randomly subdivided into 3 equal subgroups to be injected with rAAV-ES, rAAV-EYFP, or RPMI medium, inoculated with EJ cells 2 weeks later, and then killed 50 days later to observe the size of tumor. (4) 4 healthy mice and 4 mice injected with rAAV-ES for 8 weeks were killed with their hearts and brains taken out to observe the side effects. RESULTS: rAAV-ES was packaged successfully. The ES concentration in the supernatant of culture fluid of the EJ cell transfected with rAAV-ES was 54.09 ng/ml. The inhibition rate of the HUVECs chemotactic movement was 37.45%. The xenograft formation rate was 2/5 for the EJ cells transfected with rAAV-ES. The serum ES levels of the mice injected with rAAV-ES remained high. The tumor size in the mice injected with rAAV-ES was significantly smaller than those of the other groups (both P < 0.01). No pathological changes was found in the hearts and brains in the mice injected with rAAV-ES. CONCLUSION: rAAV-ES inhibits tumor angiogenesis, and tumor formation and progression. Successful packaging of rAAV-ES has laid a foundation for gene therapy of bladder cancer.

[Construction of recombinant human CD59 using ICAM-2 promoter for endothelial-specific expression in xenotransplantation].

OBJECTIVE: To construct a recombinant human CD59 gene containing intercellular adhesion molecule-2 promoter for high level endothelial-specific expression in xenotransplantation. METHODS: ICAM-2 promotor fragment and CD59-intron 1 fragment were produced by PCR from the human blood genome, and then clone these fragments into a pcDNA3-CD59 eukaryotic expression vector which was followed by digestion with the specific restricted endonuclease (for example: EcoRI, Hind III). The ICAM-2 promoter and CD59-intron 1 fragments were identified by PCR, and sequencing. The recombinant was then transfected into pig aorta endothelial cells with Lipofection, and the expression was measured by flow cytometer. RESULTS: Products of the sequences measured were in accord with the frames of the gene bank. The expression of the protein of this recombinant was positive. CONCLUSION: The CD59 recombinant gene is constructed successfully, providing a basis for transgenic research.