AIM: To investigate the effect of deleted pancreatic cancer locus 4 (DPC4) gene transfection on biological behaviors of human colorectal carcinoma cells and the role of DPC4 gene in colorectal carcinogenesis. METHODS:...AIM: To investigate the effect of deleted pancreatic cancer locus 4 (DPC4) gene transfection on biological behaviors of human colorectal carcinoma cells and the role of DPC4 gene in colorectal carcinogenesis. METHODS: PcDNA3.1-DPC4 plasmid was re-constructed by gene-recombination technology. SW620 cells, a human colorectal carcinoma cell line, were transfected with PcDNA3.1-DPC4 plasmid using lipofectamine transfecting technique. Transfected cells were selected with G418. Expression of Smad4 protein was detected in cells transfected with DPC4 gene by immunohistochemistry and Western blot. Biological characterristics of transfected cells were evaluated by population-doubling time and cloning efficiency. Alterations of percentage of S phage cells (S%) and apoptosis rate were determined by flow-cytometry. RESULTS: PcDNA3.1-DPC4 plasmid was constructed successfully. SW620 cells transfected with PcDNA3.1-DPC4 plasmid (DPC4+-SW620 cells) showed a strong intracellular expression of Smad4 protein, and the positive signal was localized in cytoplasm and nuclei, mainly in cytoplasm, where the expressions of Smad4 protein in SW620 cells transfected with PcDNA3.1 plasmid (PcDNA3.1-SW620 cells) and non-transfected SW620 cells (SW620 cells) were weaker than those in DPC4+-SW620 cells. The population-doubling time in DPC4+-SW620 cells (116 h) was significantly longer than that in SW620 cells (31 h) and PcDNA3.1-Sw620 cells (29 h) (P<0.01). The cloning efficiencies of DPC4+-SW620 cells (12%) were markedly lower than those of SW620 cells (69%) and PcDNA3.1-Sw620 cells (67%) (P<0.01). Compared with SW620 cells and PcDNA3.1-Sw620 cells, the Go-G1% of DPC4+-SW620 cells was obviously higher and the S% was markedly lower (P<0.05). Apoptosis rate of DPC4+-SW620 cells was significantly higher than that of SW620 cells and PcDNA3.1-SW620 cells. CONCLUSION: PcDNA3.1-DPC4 plasmid can be successfully re-constructed and stably transfected into human SW620cells, thereby the cells can steadily express Smad4. DPC4 protein may regulate proliferation of colorectal carcinoma cells by inhibiting cell growth and inducing cell apoptosis.展开更多
Mycelia pellet formed spontaneously in the process of cultivation was exploited as a biological carrier for whole-cell immobilization due to its unique structural characteristic. An innovative two-species whole-cell i...Mycelia pellet formed spontaneously in the process of cultivation was exploited as a biological carrier for whole-cell immobilization due to its unique structural characteristic. An innovative two-species whole-cell im- mobilization system was achieved by inoculating the marine-derived fungus Pestalotiopsis sp. J63 spores into cul- ture medium containing another fungus Penicillium janthinellum P1 pre-grown mycelia pellets for 2 days without any pretreatment. In order to evaluate the biological degradation capacity of this novel constructed immobilization system, the immobilized pellets were applied to treat paper mill effluent and decolorize dye Azure B. The use of the constructed immobilization system in the effluent resulted in successful and rapid biodegradation of numerous in- soluble fine fibers. The optimum conditions of immobilized procedure for maximum biodegradation capacity were determined using orthogonal design with biomass of P1 pellets 10 g （wet mass）, concentration of J63 spore 2x109 mlq, and immobilization time 2 d. The results demonstrate that immobilized pellets have more than 99% biodegradation capacity in a ten-hour treatment process. The kinetics of biodegradation fits the Michaelis-Menten equation well. Besides, the decolorization capability of immobilized pellets is more superior than that of P1 mycelia pellets. Overall, the present study offers a simple and reproducible way to construct a two-species whole-cell immobiliza- tion system for sewage treatment.展开更多
The influence of internal noise on the calcium oscillations is studied. It is found that stochastic calcium oscillations occur when the internal noise is considered, while the corresponding deterministic dynamics only...The influence of internal noise on the calcium oscillations is studied. It is found that stochastic calcium oscillations occur when the internal noise is considered, while the corresponding deterministic dynamics only yields a steady state. Also,. the performance of such oscillations shows two maxima with the variation of the system size, indicating the occurrence of system size resonance. This behavior is found to be intimately connected with the canard phenomenon. Interestingly, it is also found that one of the optimal system sizes matches well with the real cell size, and such a match is robust to the variation of the control parameters.展开更多
Since the discovery of HCV in 1989, the lack of a cell culture system has hampered research progress on this important human pathogen. No robust system has been obtained by empiric approaches, and HCV cell culture rem...Since the discovery of HCV in 1989, the lack of a cell culture system has hampered research progress on this important human pathogen. No robust system has been obtained by empiric approaches, and HCV cell culture remained hypothetical until 2005. The construction of functional molecular clones has served as a starting point to reconstitute a consensus infectious cDNA that was able to transcribe infectious HCV RNAs as shown by intrahepatic inoculation in a chimpanzee. Other consen- sus clones have been selected and established in a hu- man hepatoma cell line as replicons, i.e. self-replicating subgenomic or genomic viral RNAs. However, these repli- cons did not support production of infectious virus. Inter- estingly, some full-length replicons could be established without adaptive mutations and one of them was able to replicate at very high levels and to release virus particles that are infectious in cell culture and in vivo. This new cell culture system represents a major breakthrough in the HCV field and should enable a broad range of basic and applied studies to be achieved.展开更多
Autoimmune diseases are generated through irregular immune response of the human body. Psoriasis is one type of autoimmune chronic skin diseases that is differentiated by T-Cells mediated hyper-proliferation of epider...Autoimmune diseases are generated through irregular immune response of the human body. Psoriasis is one type of autoimmune chronic skin diseases that is differentiated by T-Cells mediated hyper-proliferation of epidermal Keratinocytes. Dendritic Cells and CD8＋ T-Cells have a significant role for the occurrence of this disease. In this paper, the authors have developed a mathematical model of Psoriasis involving CD4＋ T-Cells, Dendritic Ceils, CD8＋ T-Cells and Keratinocyte cell populations using the fractional differential equations with the effect of Cytokine release to observe the impact of memory on the cell-biological system. Using fractional calculus, the authors try to explore the suppressed memory, associated with the cell-biological system and to locate the position of Keratinocyte cell population as fractional derivative possess non-local property. Thus, the dynamics of Psoriasis can be predicted in a better way using fractional differential equations rather than its corresponding integer order model. Finally, the authors introduce drug into the system to obstruct the interaction between CD4＋ T-Cells and Keratinocytes to restrict the disease Psoriasis. The authors derive the Euler-Lagrange conditions for the optimality made through Matlab by developing iterative of the drug induced system. Numerical simulations are schemes.展开更多
文摘AIM: To investigate the effect of deleted pancreatic cancer locus 4 (DPC4) gene transfection on biological behaviors of human colorectal carcinoma cells and the role of DPC4 gene in colorectal carcinogenesis. METHODS: PcDNA3.1-DPC4 plasmid was re-constructed by gene-recombination technology. SW620 cells, a human colorectal carcinoma cell line, were transfected with PcDNA3.1-DPC4 plasmid using lipofectamine transfecting technique. Transfected cells were selected with G418. Expression of Smad4 protein was detected in cells transfected with DPC4 gene by immunohistochemistry and Western blot. Biological characterristics of transfected cells were evaluated by population-doubling time and cloning efficiency. Alterations of percentage of S phage cells (S%) and apoptosis rate were determined by flow-cytometry. RESULTS: PcDNA3.1-DPC4 plasmid was constructed successfully. SW620 cells transfected with PcDNA3.1-DPC4 plasmid (DPC4+-SW620 cells) showed a strong intracellular expression of Smad4 protein, and the positive signal was localized in cytoplasm and nuclei, mainly in cytoplasm, where the expressions of Smad4 protein in SW620 cells transfected with PcDNA3.1 plasmid (PcDNA3.1-SW620 cells) and non-transfected SW620 cells (SW620 cells) were weaker than those in DPC4+-SW620 cells. The population-doubling time in DPC4+-SW620 cells (116 h) was significantly longer than that in SW620 cells (31 h) and PcDNA3.1-Sw620 cells (29 h) (P<0.01). The cloning efficiencies of DPC4+-SW620 cells (12%) were markedly lower than those of SW620 cells (69%) and PcDNA3.1-Sw620 cells (67%) (P<0.01). Compared with SW620 cells and PcDNA3.1-Sw620 cells, the Go-G1% of DPC4+-SW620 cells was obviously higher and the S% was markedly lower (P<0.05). Apoptosis rate of DPC4+-SW620 cells was significantly higher than that of SW620 cells and PcDNA3.1-SW620 cells. CONCLUSION: PcDNA3.1-DPC4 plasmid can be successfully re-constructed and stably transfected into human SW620cells, thereby the cells can steadily express Smad4. DPC4 protein may regulate proliferation of colorectal carcinoma cells by inhibiting cell growth and inducing cell apoptosis.
基金Supported by the National Natural Science Foundation of China(21036005)Scientific Technology Program of Zhejiang Province(2011C33016)
文摘Mycelia pellet formed spontaneously in the process of cultivation was exploited as a biological carrier for whole-cell immobilization due to its unique structural characteristic. An innovative two-species whole-cell im- mobilization system was achieved by inoculating the marine-derived fungus Pestalotiopsis sp. J63 spores into cul- ture medium containing another fungus Penicillium janthinellum P1 pre-grown mycelia pellets for 2 days without any pretreatment. In order to evaluate the biological degradation capacity of this novel constructed immobilization system, the immobilized pellets were applied to treat paper mill effluent and decolorize dye Azure B. The use of the constructed immobilization system in the effluent resulted in successful and rapid biodegradation of numerous in- soluble fine fibers. The optimum conditions of immobilized procedure for maximum biodegradation capacity were determined using orthogonal design with biomass of P1 pellets 10 g （wet mass）, concentration of J63 spore 2x109 mlq, and immobilization time 2 d. The results demonstrate that immobilized pellets have more than 99% biodegradation capacity in a ten-hour treatment process. The kinetics of biodegradation fits the Michaelis-Menten equation well. Besides, the decolorization capability of immobilized pellets is more superior than that of P1 mycelia pellets. Overall, the present study offers a simple and reproducible way to construct a two-species whole-cell immobiliza- tion system for sewage treatment.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.20433050 and No.20673106）.
文摘The influence of internal noise on the calcium oscillations is studied. It is found that stochastic calcium oscillations occur when the internal noise is considered, while the corresponding deterministic dynamics only yields a steady state. Also,. the performance of such oscillations shows two maxima with the variation of the system size, indicating the occurrence of system size resonance. This behavior is found to be intimately connected with the canard phenomenon. Interestingly, it is also found that one of the optimal system sizes matches well with the real cell size, and such a match is robust to the variation of the control parameters.
文摘Since the discovery of HCV in 1989, the lack of a cell culture system has hampered research progress on this important human pathogen. No robust system has been obtained by empiric approaches, and HCV cell culture remained hypothetical until 2005. The construction of functional molecular clones has served as a starting point to reconstitute a consensus infectious cDNA that was able to transcribe infectious HCV RNAs as shown by intrahepatic inoculation in a chimpanzee. Other consen- sus clones have been selected and established in a hu- man hepatoma cell line as replicons, i.e. self-replicating subgenomic or genomic viral RNAs. However, these repli- cons did not support production of infectious virus. Inter- estingly, some full-length replicons could be established without adaptive mutations and one of them was able to replicate at very high levels and to release virus particles that are infectious in cell culture and in vivo. This new cell culture system represents a major breakthrough in the HCV field and should enable a broad range of basic and applied studies to be achieved.
基金supported by the Council of Scientific and Industrial Research,Government of India under Grant No.38(1320)/12/EMR-II
文摘Autoimmune diseases are generated through irregular immune response of the human body. Psoriasis is one type of autoimmune chronic skin diseases that is differentiated by T-Cells mediated hyper-proliferation of epidermal Keratinocytes. Dendritic Cells and CD8＋ T-Cells have a significant role for the occurrence of this disease. In this paper, the authors have developed a mathematical model of Psoriasis involving CD4＋ T-Cells, Dendritic Ceils, CD8＋ T-Cells and Keratinocyte cell populations using the fractional differential equations with the effect of Cytokine release to observe the impact of memory on the cell-biological system. Using fractional calculus, the authors try to explore the suppressed memory, associated with the cell-biological system and to locate the position of Keratinocyte cell population as fractional derivative possess non-local property. Thus, the dynamics of Psoriasis can be predicted in a better way using fractional differential equations rather than its corresponding integer order model. Finally, the authors introduce drug into the system to obstruct the interaction between CD4＋ T-Cells and Keratinocytes to restrict the disease Psoriasis. The authors derive the Euler-Lagrange conditions for the optimality made through Matlab by developing iterative of the drug induced system. Numerical simulations are schemes.
